Merge branch 'AX25_FM' into M17_AX25_FM

AX25Defines.h

@@ -0,0 +1,36 @@
+/*
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#if !defined(AX25DEFINES_H)
+#define  AX25DEFINES_H
+
+const uint8_t AX25_RADIO_SYMBOL_LENGTH = 20U;      // At 24 kHz sample rate
+
+const uint8_t AX25_FRAME_START = 0x7EU;
+const uint8_t AX25_FRAME_END   = 0x7EU;
+const uint8_t AX25_FRAME_ABORT = 0xFEU;
+
+const uint8_t AX25_MAX_ONES    = 5U;
+
+const uint16_t AX25_MIN_FRAME_LENGTH = 17U;        // Callsign (7) + Callsign (7) + Control (1) + Checksum (2)
+
+const uint16_t AX25_MAX_FRAME_LENGTH = 330U;       // Callsign (7) + Callsign (7) + 8 Digipeaters (56) +
+                                                   // Control (1) + PID (1) + Data (256) + Checksum (2)
+
+#endif
+

AX25Demodulator.cpp

@@ -0,0 +1,314 @@
+/*
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
+ *   Copyright 2015-2019 Mobilinkd LLC <rob@mobilinkd.com>
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "Config.h"
+#include "Globals.h"
+#include "AX25Demodulator.h"
+#include "AX25Defines.h"
+
+const float32_t SAMPLE_RATE = 24000.0F;
+const float32_t SYMBOL_RATE = 1200.0F;
+
+const uint16_t DELAY_LEN = 11U;
+
+const float32_t SAMPLES_PER_SYMBOL = SAMPLE_RATE / SYMBOL_RATE;
+const float32_t PLL_LIMIT          = SAMPLES_PER_SYMBOL / 2.0F;
+
+const uint32_t LPF_FILTER_LEN = 48U;
+
+q15_t LPF_FILTER_COEFFS[] = {
+    -2,   -8,  -17,  -28,  -40,  -47,  -47,  -34,
+    -5,   46,  122,  224,  354,  510,  689,  885,
+  1092, 1302, 1506, 1693, 1856, 1987, 2077, 2124,
+  2124, 2077, 1987, 1856, 1693, 1506, 1302, 1092,
+  885,  689,  510,  354,  224,  122,   46,    -5,
+  -34,  -47,  -47,  -40,  -28,  -17,   -8,    -2
+};
+
+// Lock low-pass filter taps (80Hz Bessel)
+// scipy.signal:
+//      b, a = bessel(4, [80.0/(1200/2)], 'lowpass')
+//
+const uint8_t PLL_IIR_SIZE = 5U;
+
+const float32_t PLL_LOCK_B[] = {
+    1.077063e-03,4.308253e-03,6.462379e-03,4.308253e-03,1.077063e-03};
+
+const float32_t PLL_LOCK_A[] = {
+    1.000000e+00,-2.774567e+00,2.962960e+00,-1.437990e+00,2.668296e-01};
+
+// 64 Hz loop filter.
+// scipy.signal:
+//      loop_coeffs = firwin(9, [64.0/(1200/2)], width = None,
+//          pass_zero = True, scale = True, window='hann')
+//
+const uint32_t PLL_FILTER_LEN = 7U;
+
+float32_t PLL_FILTER_COEFFS[] = {3.196252e-02F, 1.204223e-01F, 2.176819e-01F, 2.598666e-01F, 2.176819e-01F, 1.204223e-01F, 3.196252e-02F};
+
+CAX25Demodulator::CAX25Demodulator(int8_t n) :
+m_frame(),
+m_twist(n),
+m_lpfFilter(),
+m_lpfState(),
+m_delayLine(NULL),
+m_delayPos(0U),
+m_nrziState(false),
+m_pllFilter(),
+m_pllState(),
+m_pllLast(false),
+m_pllBits(1U),
+m_pllCount(0.0F),
+m_pllJitter(0.0F),
+m_pllDCD(false),
+m_iirHistory(),
+m_hdlcOnes(0U),
+m_hdlcFlag(false),
+m_hdlcBuffer(0U),
+m_hdlcBits(0U),
+m_hdlcState(AX25_IDLE)
+{
+  m_delayLine = new bool[DELAY_LEN];
+
+  m_lpfFilter.numTaps = LPF_FILTER_LEN;
+  m_lpfFilter.pState  = m_lpfState;
+  m_lpfFilter.pCoeffs = LPF_FILTER_COEFFS;
+
+  m_pllFilter.numTaps = PLL_FILTER_LEN;
+  m_pllFilter.pState  = m_pllState;
+  m_pllFilter.pCoeffs = PLL_FILTER_COEFFS;
+
+  for (uint8_t i = 0U; i < PLL_IIR_SIZE; i++)
+    m_iirHistory[i] = 0.0F;
+}
+
+bool CAX25Demodulator::process(q15_t* samples, uint8_t length, CAX25Frame& frame)
+{
+  bool result = false;
+
+  q15_t fa[RX_BLOCK_SIZE];
+  m_twist.process(samples, fa, RX_BLOCK_SIZE);
+
+  int16_t buffer[RX_BLOCK_SIZE];
+  for (uint8_t i = 0; i < length; i++) {
+      bool   level = (fa[i] >= 0);
+      bool delayed = delay(level);
+      buffer[i] = (int16_t(level ^ delayed) << 1) - 1;
+  }
+
+  q15_t fc[RX_BLOCK_SIZE];
+  ::arm_fir_fast_q15(&m_lpfFilter, buffer, fc, RX_BLOCK_SIZE);
+
+  for (uint8_t i = 0; i < length; i++) {
+    bool bit = fc[i] >= 0;
+    bool sample = PLL(bit);
+
+    if (sample) {
+      // We will only ever get one frame because there are
+      // not enough bits in a block for more than one.
+      if (result) {
+        HDLC(NRZI(bit));
+      } else {
+        result = HDLC(NRZI(bit));
+        if (result) {
+          // Copy the frame data.
+          ::memcpy(frame.m_data, m_frame.m_data, AX25_MAX_PACKET_LEN);
+          frame.m_length = m_frame.m_length;
+          frame.m_fcs    = m_frame.m_fcs;
+          m_frame.m_length = 0U;
+        }
+      }
+    }
+  }
+
+  return result;
+}
+
+bool CAX25Demodulator::delay(bool b)
+{
+  bool r = m_delayLine[m_delayPos];
+
+  m_delayLine[m_delayPos++] = b;
+
+  if (m_delayPos >= DELAY_LEN)
+    m_delayPos = 0U;
+
+  return r;
+}
+
+bool CAX25Demodulator::NRZI(bool b)
+{
+  bool result = (b == m_nrziState);
+
+  m_nrziState = b;
+
+  return result;
+}
+
+bool CAX25Demodulator::PLL(bool input)
+{
+  bool sample = false;
+		
+  if (input != m_pllLast || m_pllBits > 16U) {
+    // Record transition.
+    m_pllLast = input;
+
+    if (m_pllCount > PLL_LIMIT)
+      m_pllCount -= SAMPLES_PER_SYMBOL;
+
+    float32_t adjust = m_pllBits > 16U ? 5.0F : 0.0F;
+    float32_t offset = m_pllCount / float32_t(m_pllBits);
+    float32_t jitter;
+    ::arm_fir_f32(&m_pllFilter, &offset, &jitter, 1U);
+
+    float32_t absOffset = adjust;
+    if (offset < 0.0F)
+      absOffset -= offset;
+    else
+      absOffset += offset;
+    m_pllJitter = iir(absOffset);
+
+    m_pllCount -= jitter / 2.0F;
+    m_pllBits = 1U;
+  } else {
+    if (m_pllCount > PLL_LIMIT) {
+      sample = true;
+      m_pllCount -= SAMPLES_PER_SYMBOL;
+      m_pllBits++;
+    }
+  }
+
+  m_pllCount += 1.0F;
+
+  return sample;
+}
+
+bool CAX25Demodulator::HDLC(bool b)
+{
+  if (m_hdlcOnes == AX25_MAX_ONES) {
+    if (b) {
+      // flag byte
+      m_hdlcFlag = true;
+    } else {
+      // bit stuffing...
+      m_hdlcFlag = false;
+      m_hdlcOnes = 0U;
+      return false;
+    }
+  }
+
+  m_hdlcBuffer >>= 1;
+  m_hdlcBuffer |= b ? 128U : 0U;
+  m_hdlcBits++;                      // Free-running until Sync byte.
+
+  if (b)
+    m_hdlcOnes++;
+  else
+    m_hdlcOnes = 0U;
+
+  if (m_hdlcFlag) {
+    bool result = false;
+
+    switch (m_hdlcBuffer) {
+      case AX25_FRAME_END:
+        if (m_frame.m_length >= AX25_MIN_FRAME_LENGTH) {
+          result = m_frame.checkCRC();
+          if (!result)
+              m_frame.m_length = 0U;
+        } else {
+            m_frame.m_length = 0U;
+        }
+        m_hdlcState = AX25_SYNC;
+        m_hdlcFlag = false;
+        m_hdlcBits = 0U;
+        break;
+
+      case AX25_FRAME_ABORT:
+        // Frame aborted
+        m_frame.m_length = 0U;
+        m_hdlcState = AX25_IDLE;
+        m_hdlcFlag = false;
+        m_hdlcBits = 0U;
+        break;
+
+      default:
+        break;
+    }
+
+    return result;
+  }
+
+  switch (m_hdlcState) {
+    case AX25_IDLE:
+      break;
+
+    case AX25_SYNC:
+      if (m_hdlcBits == 8U) {    // 8th bit.
+        // Start of frame data.
+        m_hdlcState = AX25_RECEIVE;
+        m_frame.append(m_hdlcBuffer);
+        m_hdlcBits = 0U;
+      }
+      break;
+
+    case AX25_RECEIVE:
+      if (m_hdlcBits == 8U) {    // 8th bit.
+        m_frame.append(m_hdlcBuffer);
+        m_hdlcBits = 0U;
+      }
+      break;
+
+    default:
+      break;
+  }
+
+  return false;
+}
+
+void CAX25Demodulator::setTwist(int8_t n)
+{
+  m_twist.setTwist(n);
+}
+
+bool CAX25Demodulator::isDCD()
+{
+  if (m_pllJitter <= (SAMPLES_PER_SYMBOL * 0.03F))
+    m_pllDCD = true;
+  else if (m_pllJitter >= (SAMPLES_PER_SYMBOL * 0.15F))
+    m_pllDCD = false;
+
+  return m_pllDCD;
+}
+
+float32_t CAX25Demodulator::iir(float32_t input)
+{
+  for (int8_t i = int8_t(PLL_IIR_SIZE) - 1; i != 0; i--)
+    m_iirHistory[i] = m_iirHistory[i - 1];
+
+  m_iirHistory[0] = input;
+  for (uint8_t i = 1U; i < PLL_IIR_SIZE; i++)
+    m_iirHistory[0] -= PLL_LOCK_A[i] * m_iirHistory[i];
+
+  float32_t result = 0.0F;
+  for (uint8_t i = 0U; i < PLL_IIR_SIZE; i++)
+    result += PLL_LOCK_B[i] * m_iirHistory[i];
+
+  return result;
+}
+

AX25Demodulator.h

@@ -0,0 +1,73 @@
+/*
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#if !defined(AX25Demodulator_H)
+#define  AX25Demodulator_H
+
+#include "Config.h"
+
+#include "AX25Frame.h"
+#include "AX25Twist.h"
+
+enum AX25_STATE {
+  AX25_IDLE,
+  AX25_SYNC,
+  AX25_RECEIVE
+};
+
+class CAX25Demodulator {
+public:
+  CAX25Demodulator(int8_t n);
+
+  bool process(q15_t* samples, uint8_t length, CAX25Frame& frame);
+
+  void setTwist(int8_t n);
+
+  bool isDCD();
+
+private:
+  CAX25Frame           m_frame;
+  CAX25Twist           m_twist;
+  arm_fir_instance_q15 m_lpfFilter;
+  q15_t                m_lpfState[70U];     // NoTaps + BlockSize - 1, 48 + 20 - 1 plus some spare
+  bool*                m_delayLine;
+  uint16_t             m_delayPos;
+  bool                 m_nrziState;
+  arm_fir_instance_f32 m_pllFilter;
+  float32_t            m_pllState[20U];     // NoTaps + BlockSize - 1, 7 + 1 - 1 plus some spare
+  bool                 m_pllLast;
+  uint8_t              m_pllBits;
+  float32_t            m_pllCount;
+  float32_t            m_pllJitter;
+  bool                 m_pllDCD;
+  float32_t            m_iirHistory[5U];
+  uint16_t             m_hdlcOnes;
+  bool                 m_hdlcFlag;
+  uint16_t             m_hdlcBuffer;
+  uint16_t             m_hdlcBits;
+  AX25_STATE           m_hdlcState;
+
+  bool delay(bool b);
+  bool NRZI(bool b);
+  bool PLL(bool b);
+  bool HDLC(bool b);
+  float32_t iir(float32_t input);
+};
+
+#endif
+

AX25Frame.cpp

@@ -0,0 +1,122 @@
+/*
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "Config.h"
+#include "Globals.h"
+#include "AX25Frame.h"
+
+const uint16_t CCITT_TABLE[] = {
+	0x0000,0x1189,0x2312,0x329b,0x4624,0x57ad,0x6536,0x74bf,
+	0x8c48,0x9dc1,0xaf5a,0xbed3,0xca6c,0xdbe5,0xe97e,0xf8f7,
+	0x1081,0x0108,0x3393,0x221a,0x56a5,0x472c,0x75b7,0x643e,
+	0x9cc9,0x8d40,0xbfdb,0xae52,0xdaed,0xcb64,0xf9ff,0xe876,
+	0x2102,0x308b,0x0210,0x1399,0x6726,0x76af,0x4434,0x55bd,
+	0xad4a,0xbcc3,0x8e58,0x9fd1,0xeb6e,0xfae7,0xc87c,0xd9f5,
+	0x3183,0x200a,0x1291,0x0318,0x77a7,0x662e,0x54b5,0x453c,
+	0xbdcb,0xac42,0x9ed9,0x8f50,0xfbef,0xea66,0xd8fd,0xc974,
+	0x4204,0x538d,0x6116,0x709f,0x0420,0x15a9,0x2732,0x36bb,
+	0xce4c,0xdfc5,0xed5e,0xfcd7,0x8868,0x99e1,0xab7a,0xbaf3,
+	0x5285,0x430c,0x7197,0x601e,0x14a1,0x0528,0x37b3,0x263a,
+	0xdecd,0xcf44,0xfddf,0xec56,0x98e9,0x8960,0xbbfb,0xaa72,
+	0x6306,0x728f,0x4014,0x519d,0x2522,0x34ab,0x0630,0x17b9,
+	0xef4e,0xfec7,0xcc5c,0xddd5,0xa96a,0xb8e3,0x8a78,0x9bf1,
+	0x7387,0x620e,0x5095,0x411c,0x35a3,0x242a,0x16b1,0x0738,
+	0xffcf,0xee46,0xdcdd,0xcd54,0xb9eb,0xa862,0x9af9,0x8b70,
+	0x8408,0x9581,0xa71a,0xb693,0xc22c,0xd3a5,0xe13e,0xf0b7,
+	0x0840,0x19c9,0x2b52,0x3adb,0x4e64,0x5fed,0x6d76,0x7cff,
+	0x9489,0x8500,0xb79b,0xa612,0xd2ad,0xc324,0xf1bf,0xe036,
+	0x18c1,0x0948,0x3bd3,0x2a5a,0x5ee5,0x4f6c,0x7df7,0x6c7e,
+	0xa50a,0xb483,0x8618,0x9791,0xe32e,0xf2a7,0xc03c,0xd1b5,
+	0x2942,0x38cb,0x0a50,0x1bd9,0x6f66,0x7eef,0x4c74,0x5dfd,
+	0xb58b,0xa402,0x9699,0x8710,0xf3af,0xe226,0xd0bd,0xc134,
+	0x39c3,0x284a,0x1ad1,0x0b58,0x7fe7,0x6e6e,0x5cf5,0x4d7c,
+	0xc60c,0xd785,0xe51e,0xf497,0x8028,0x91a1,0xa33a,0xb2b3,
+	0x4a44,0x5bcd,0x6956,0x78df,0x0c60,0x1de9,0x2f72,0x3efb,
+	0xd68d,0xc704,0xf59f,0xe416,0x90a9,0x8120,0xb3bb,0xa232,
+	0x5ac5,0x4b4c,0x79d7,0x685e,0x1ce1,0x0d68,0x3ff3,0x2e7a,
+	0xe70e,0xf687,0xc41c,0xd595,0xa12a,0xb0a3,0x8238,0x93b1,
+	0x6b46,0x7acf,0x4854,0x59dd,0x2d62,0x3ceb,0x0e70,0x1ff9,
+	0xf78f,0xe606,0xd49d,0xc514,0xb1ab,0xa022,0x92b9,0x8330,
+	0x7bc7,0x6a4e,0x58d5,0x495c,0x3de3,0x2c6a,0x1ef1,0x0f78 };
+
+CAX25Frame::CAX25Frame(const uint8_t* data, uint16_t length) :
+m_data(),
+m_length(0U),
+m_fcs(0U)
+{
+  for (uint16_t i = 0U; i < length && i < (AX25_MAX_PACKET_LEN - 2U); i++)
+    m_data[m_length++] = data[i];
+}
+
+CAX25Frame::CAX25Frame() :
+m_data(),
+m_length(0U),
+m_fcs(0U)
+{
+}
+
+bool CAX25Frame::append(uint16_t c)
+{
+  if (m_length == AX25_MAX_PACKET_LEN)
+    return false;
+
+  m_data[m_length++] = uint8_t(c);
+
+  return true;
+}
+
+bool CAX25Frame::checkCRC()
+{
+  union {
+    uint16_t crc16;
+    uint8_t  crc8[2U];
+  };
+
+  crc16 = 0xFFFFU;
+  for (uint16_t i = 0U; i < (m_length - 2U); i++)
+    crc16 = uint16_t(crc8[1U]) ^ CCITT_TABLE[crc8[0U] ^ m_data[i]];
+
+  crc16 = ~crc16;
+
+  if (crc8[0U] == m_data[m_length - 2U] && crc8[1U] == m_data[m_length - 1U]) {
+    m_fcs = crc16;
+    return true;
+  } else {
+    return false;
+  }
+}
+
+void CAX25Frame::addCRC()
+{
+  union {
+    uint16_t crc16;
+    uint8_t  crc8[2U];
+  };
+
+  crc16 = 0xFFFFU;
+  for (uint16_t i = 0U; i < m_length; i++)
+    crc16 = uint16_t(crc8[1U]) ^ CCITT_TABLE[crc8[0U] ^ m_data[i]];
+
+  crc16 = ~crc16;
+
+  m_fcs = crc16;
+
+  m_data[m_length++] = crc8[0U];
+  m_data[m_length++] = crc8[1U];
+}
+

AX25Frame.h

@@ -0,0 +1,43 @@
+/*
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#if !defined(AX25Frame_H)
+#define  AX25Frame_H
+
+#include "Config.h"
+
+const uint16_t AX25_MAX_PACKET_LEN = 300U;
+
+class CAX25Frame {
+public:
+  CAX25Frame(const uint8_t* data, uint16_t length);
+  CAX25Frame();
+
+  bool append(uint16_t c);
+
+  bool checkCRC();
+
+  void addCRC();
+
+  uint8_t  m_data[AX25_MAX_PACKET_LEN];
+  uint16_t m_length;
+  uint16_t m_fcs;
+};
+
+#endif
+

AX25RX.cpp

@@ -0,0 +1,205 @@
+/*
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "Config.h"
+#include "Globals.h"
+#include "AX25RX.h"
+
+/*
+ * Generated with Scipy Filter, 152 coefficients, 1100-2300Hz bandpass,
+ * Hann window, starting and ending 0 value coefficients removed.
+ *
+ * np.array(
+ *  firwin2(152,
+ *      [
+ *          0.0,
+ *          1000.0/(sample_rate/2),
+ *          1100.0/(sample_rate/2),
+ *          2350.0/(sample_rate/2),
+ *          2500.0/(sample_rate/2),
+ *          1.0
+ *      ],
+ *      [0,0,1,1,0,0],
+ *      antisymmetric = False,
+ *      window='hann') * 32768,
+ *  dtype=int)[10:-10]
+ */
+
+const uint32_t FILTER_LEN = 130U;
+
+q15_t FILTER_COEFFS[] = {
+      5,    12,    18,    21,   19,   11,    -2,   -15,   -25,   -27,
+    -21,   -11,    -3,    -5,  -19,  -43,   -69,   -83,   -73,   -35,
+     27,    98,   155,   180,  163,  109,    39,   -20,   -45,   -26,
+     23,    74,    89,    39,  -81, -247,  -407,  -501,  -480,  -334,
+    -92,   175,   388,   479,  429,  275,    99,     5,    68,   298,
+    626,   913,   994,   740,  115, -791, -1770, -2544, -2847, -2509,
+  -1527,   -76,  1518,  2875, 3653, 3653,  2875,  1518,   -76, -1527,
+  -2509, -2847, -2544, -1770, -791,  115,   740,   994,   913,   626,
+    298,    68,     5,    99,  275,  429,   479,   388,   175,   -92,
+   -334,  -480,  -501,  -407, -247,  -81,    39,    89,    74,    23,
+    -26,   -45,   -20,    39,  109,  163,   180,   155,    98,    27,
+    -35,   -73,   -83,   -69,  -43,  -19,    -5,    -3,   -11,   -21,
+    -27,   -25,   -15,    -2,   11,   19,    21,    18,    12,     5
+};
+
+CAX25RX::CAX25RX() :
+m_filter(),
+m_state(),
+m_demod1(3),
+m_demod2(6),
+m_demod3(9),
+m_lastFCS(0U),
+m_count(0U),
+m_slotTime(30U),
+m_slotCount(0U),
+m_pPersist(128U),
+m_dcd(false),
+m_canTX(false),
+m_x(1U),
+m_a(0xB7U),
+m_b(0x73U),
+m_c(0xF6U)
+{
+  m_filter.numTaps = FILTER_LEN;
+  m_filter.pState  = m_state;
+  m_filter.pCoeffs = FILTER_COEFFS;
+
+  initRand();
+}
+
+void CAX25RX::samples(q15_t* samples, uint8_t length)
+{
+  q15_t output[RX_BLOCK_SIZE];
+  ::arm_fir_fast_q15(&m_filter, samples, output, RX_BLOCK_SIZE);
+
+  m_count++;
+
+  CAX25Frame frame;
+
+  bool ret = m_demod1.process(output, length, frame);
+  if (ret) {
+    if (frame.m_fcs != m_lastFCS || m_count > 2U) {
+      m_lastFCS = frame.m_fcs;
+      m_count   = 0U;
+      serial.writeAX25Data(frame.m_data, frame.m_length - 2U);
+    }
+    DEBUG1("Decoder 1 reported");
+  }
+
+  ret = m_demod2.process(output, length, frame);
+  if (ret) {
+    if (frame.m_fcs != m_lastFCS || m_count > 2U) {
+      m_lastFCS = frame.m_fcs;
+      m_count   = 0U;
+      serial.writeAX25Data(frame.m_data, frame.m_length - 2U);
+    }
+    DEBUG1("Decoder 2 reported");
+  }
+
+  ret = m_demod3.process(output, length, frame);
+  if (ret) {
+    if (frame.m_fcs != m_lastFCS || m_count > 2U) {
+      m_lastFCS = frame.m_fcs;
+      m_count   = 0U;
+      serial.writeAX25Data(frame.m_data, frame.m_length - 2U);
+    }
+    DEBUG1("Decoder 3 reported");
+  }
+
+  m_slotCount += RX_BLOCK_SIZE;
+  if (m_slotCount >= m_slotTime) {
+    m_slotCount = 0U;
+
+    bool dcd1 = m_demod1.isDCD();
+    bool dcd2 = m_demod2.isDCD();
+    bool dcd3 = m_demod3.isDCD();
+    
+    if (dcd1 || dcd2 || dcd3) {
+      if (!m_dcd) {
+        io.setDecode(true);
+        io.setADCDetection(true);
+        m_dcd = true;
+      }
+
+      m_canTX = false;
+    } else {
+      if (m_dcd) {
+        io.setDecode(false);
+        io.setADCDetection(false);
+        m_dcd = false;
+      }
+
+      m_canTX = m_pPersist >= rand();
+    }
+  }
+}
+
+bool CAX25RX::canTX() const
+{
+  return m_canTX;
+}
+
+void CAX25RX::setParams(int8_t twist, uint8_t slotTime, uint8_t pPersist)
+{
+  m_demod1.setTwist(twist - 3);
+  m_demod2.setTwist(twist);
+  m_demod3.setTwist(twist + 3);
+
+  m_slotTime = slotTime * 240U;    // Slot time in samples
+  m_pPersist = pPersist;
+}
+
+// Taken from https://www.electro-tech-online.com/threads/ultra-fast-pseudorandom-number-generator-for-8-bit.124249/
+//X ABC Algorithm Random Number Generator for 8-Bit Devices:
+//This is a small PRNG, experimentally verified to have at least a 50 million byte period
+//by generating 50 million bytes and observing that there were no overapping sequences and repeats.
+//This generator passes serial correlation, entropy , Monte Carlo Pi value, arithmetic mean,
+//And many other statistical tests. This generator may have a period of up to 2^32, but this has
+//not been verified.
+//
+// By XORing 3 bytes into the a,b, and c registers, you can add in entropy from 
+//an external source easily.
+//
+//This generator is free to use, but is not suitable for cryptography due to its short period(by //cryptographic standards) and simple construction. No attempt was made to make this generator 
+// suitable for cryptographic use.
+//
+//Due to the use of a constant counter, the generator should be resistant to latching up.
+//A significant performance gain is had in that the x variable is only ever incremented.
+//
+//Only 4 bytes of ram are needed for the internal state, and generating a byte requires 3 XORs , //2 ADDs, one bit shift right , and one increment. Difficult or slow operations like multiply, etc 
+//were avoided for maximum speed on ultra low power devices.
+
+
+void CAX25RX::initRand() //Can also be used to seed the rng with more entropy during use.
+{
+  m_a = (m_a ^ m_c ^ m_x);
+  m_b = (m_b + m_a);
+  m_c = (m_c + (m_b >> 1) ^ m_a);
+}
+
+uint8_t CAX25RX::rand()
+{
+  m_x++;                           //x is incremented every round and is not affected by any other variable
+
+  m_a = (m_a ^ m_c ^ m_x);         //note the mix of addition and XOR
+  m_b = (m_b + m_a);               //And the use of very few instructions
+  m_c = (m_c + (m_b >> 1) ^ m_a);  //the right shift is to ensure that high-order bits from b can affect  
+
+  return uint8_t(m_c);             //low order bits of other variables
+}

AX25RX.h

@@ -0,0 +1,59 @@
+/*
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#if !defined(AX25RX_H)
+#define  AX25RX_H
+
+#include "Config.h"
+
+#include "AX25Demodulator.h"
+
+class CAX25RX {
+public:
+  CAX25RX();
+
+  void samples(q15_t* samples, uint8_t length);
+
+  void setParams(int8_t twist, uint8_t slotTime, uint8_t pPersist);
+
+  bool canTX() const;
+
+private:
+  arm_fir_instance_q15 m_filter;
+  q15_t                m_state[160U];    // NoTaps + BlockSize - 1, 130 + 20 - 1 plus some spare
+  CAX25Demodulator     m_demod1;
+  CAX25Demodulator     m_demod2;
+  CAX25Demodulator     m_demod3;
+  uint16_t             m_lastFCS;
+  uint32_t             m_count;
+  uint32_t             m_slotTime;
+  uint32_t             m_slotCount;
+  uint8_t              m_pPersist;
+  bool                 m_dcd;
+  bool                 m_canTX;
+  uint8_t              m_x;
+  uint8_t              m_a;
+  uint8_t              m_b;
+  uint8_t              m_c;
+  
+  void initRand();
+  uint8_t rand();
+};
+
+#endif
+

AX25TX.cpp

@@ -0,0 +1,186 @@
+/*
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "Config.h"
+#include "Globals.h"
+#include "AX25TX.h"
+
+#include "AX25Defines.h"
+#include "AX25Frame.h"
+
+
+const uint8_t START_FLAG[] = { AX25_FRAME_START };
+const uint8_t END_FLAG[]   = { AX25_FRAME_END };
+
+const uint8_t BIT_MASK_TABLE1[] = { 0x80U, 0x40U, 0x20U, 0x10U, 0x08U, 0x04U, 0x02U, 0x01U };
+
+#define WRITE_BIT1(p,i,b) p[(i)>>3] = (b) ? (p[(i)>>3] | BIT_MASK_TABLE1[(i)&7]) : (p[(i)>>3] & ~BIT_MASK_TABLE1[(i)&7])
+#define READ_BIT1(p,i)    (p[(i)>>3] & BIT_MASK_TABLE1[(i)&7])
+
+const uint8_t BIT_MASK_TABLE2[] = { 0x01U, 0x02U, 0x04U, 0x08U, 0x10U, 0x20U, 0x40U, 0x80U };
+
+#define WRITE_BIT2(p,i,b) p[(i)>>3] = (b) ? (p[(i)>>3] | BIT_MASK_TABLE2[(i)&7]) : (p[(i)>>3] & ~BIT_MASK_TABLE2[(i)&7])
+#define READ_BIT2(p,i)    (p[(i)>>3] & BIT_MASK_TABLE2[(i)&7])
+
+const uint16_t AUDIO_TABLE_LEN = 120U;
+
+const q15_t AUDIO_TABLE_DATA[] = {
+  0, 214, 428, 641, 851, 1060, 1265, 1468, 1666, 1859, 2048, 2230, 2407, 2577, 2740, 2896, 3043, 3182, 3313, 3434, 3546, 3649,
+  3741, 3823, 3895, 3955, 4006, 4045, 4073, 4089, 4095, 4089, 4073, 4045, 4006, 3955, 3895, 3823, 3741, 3649, 3546, 3434, 3313,
+  3182, 3043, 2896, 2740, 2577, 2407, 2230, 2048, 1859, 1666, 1468, 1265, 1060, 851, 641, 428, 214, 0, -214, -428, -641, -851,
+  -1060, -1265, -1468, -1666, -1859, -2047, -2230, -2407, -2577, -2740, -2896, -3043, -3182, -3313, -3434, -3546, -3649, -3741,
+  -3823, -3895, -3955, -4006, -4045, -4073, -4089, -4095, -4089, -4073, -4045, -4006, -3955, -3895, -3823, -3741, -3649, -3546,
+  -3434, -3313, -3182, -3043, -2896, -2740, -2577, -2407, -2230, -2047, -1859, -1666, -1468, -1265, -1060, -851, -641, -428, -214
+};
+
+CAX25TX::CAX25TX() :
+m_poBuffer(),
+m_poLen(0U),
+m_poPtr(0U),
+m_txDelay(360U),
+m_tablePtr(0U),
+m_nrzi(false)
+{
+}
+
+void CAX25TX::process()
+{
+  if (m_poLen == 0U)
+    return;
+
+  if (!m_duplex) {
+    if (m_poPtr == 0U) {
+      bool tx = ax25RX.canTX();
+      if (!tx)
+        return;
+    }
+  }
+
+  uint16_t space = io.getSpace();
+
+  while (space > AX25_RADIO_SYMBOL_LENGTH) {
+    bool b = READ_BIT1(m_poBuffer, m_poPtr) != 0U;
+    m_poPtr++;
+
+    writeBit(b);
+
+    space -= AX25_RADIO_SYMBOL_LENGTH;
+
+    if (m_poPtr >= m_poLen) {
+      m_poPtr = 0U;
+      m_poLen = 0U;
+      return;
+    }
+  }
+}
+
+uint8_t CAX25TX::writeData(const uint8_t* data, uint16_t length)
+{
+  CAX25Frame frame(data, length);
+  frame.addCRC();
+
+  m_poLen    = 0U;
+  m_poPtr    = 0U;
+  m_nrzi     = false;
+  m_tablePtr = 0U;
+
+  // Add TX delay
+  for (uint16_t i = 0U; i < m_txDelay; i++, m_poLen++) {
+    bool preamble = NRZI(false);
+    WRITE_BIT1(m_poBuffer, m_poLen, preamble);
+  }
+
+  // Add the Start Flag
+  for (uint16_t i = 0U; i < 8U; i++, m_poLen++) {
+    bool b1 = READ_BIT1(START_FLAG, i) != 0U;
+    bool b2 = NRZI(b1);
+    WRITE_BIT1(m_poBuffer, m_poLen, b2);
+  }
+
+  uint8_t ones = 0U;
+  for (uint16_t i = 0U; i < (frame.m_length * 8U); i++) {
+    bool b1 = READ_BIT2(frame.m_data, i) != 0U;
+    bool b2 = NRZI(b1);
+    WRITE_BIT1(m_poBuffer, m_poLen, b2);
+    m_poLen++;
+
+    if (b1) {
+      ones++;
+      if (ones == AX25_MAX_ONES) {
+        // Bit stuffing
+        bool b = NRZI(false);
+        WRITE_BIT1(m_poBuffer, m_poLen, b);
+        m_poLen++;
+        ones = 0U;
+      }
+    } else {
+      ones = 0U;
+    }
+  }
+
+  // Add the End Flag
+  for (uint16_t i = 0U; i < 8U; i++, m_poLen++) {
+    bool b1 = READ_BIT1(END_FLAG, i) != 0U;
+    bool b2 = NRZI(b1);
+    WRITE_BIT1(m_poBuffer, m_poLen, b2);
+  }
+
+  return 0U;
+}
+
+void CAX25TX::writeBit(bool b)
+{
+  q15_t buffer[AX25_RADIO_SYMBOL_LENGTH];
+  for (uint8_t i = 0U; i < AX25_RADIO_SYMBOL_LENGTH; i++) {
+    q15_t value = AUDIO_TABLE_DATA[m_tablePtr];
+
+    if (b) {
+      // De-emphasise the lower frequency by 6dB
+      value >>= 2;
+      m_tablePtr += 6U;
+    } else {
+      m_tablePtr += 11U;
+    }
+
+    buffer[i] = value;
+
+    if (m_tablePtr >= AUDIO_TABLE_LEN)
+      m_tablePtr -= AUDIO_TABLE_LEN;
+  }
+
+  io.write(STATE_AX25, buffer, AX25_RADIO_SYMBOL_LENGTH);
+}
+
+void CAX25TX::setTXDelay(uint8_t delay)
+{
+  m_txDelay = delay * 12U;
+}
+
+uint8_t CAX25TX::getSpace() const
+{
+  return m_poLen == 0U ? 255U : 0U;
+}
+
+bool CAX25TX::NRZI(bool b)
+{
+    if (!b)
+      m_nrzi = !m_nrzi;
+
+    return m_nrzi;
+}
+

AX25TX.h

@@ -0,0 +1,49 @@
+/*
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#if !defined(AX25TX_H)
+#define  AX25TX_H
+
+#include "Config.h"
+
+class CAX25TX {
+public:
+  CAX25TX();
+
+  uint8_t writeData(const uint8_t* data, uint16_t length);
+
+  void process();
+
+  void setTXDelay(uint8_t delay);
+
+  uint8_t getSpace() const;
+
+private:
+  uint8_t    m_poBuffer[600U];
+  uint16_t   m_poLen;
+  uint16_t   m_poPtr;
+  uint16_t   m_txDelay;
+  uint16_t   m_tablePtr;
+  bool       m_nrzi;
+
+  void writeBit(bool b);
+  bool NRZI(bool b);
+};
+
+#endif
+

AX25Twist.cpp

@@ -0,0 +1,311 @@
+/*
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "Config.h"
+#include "Globals.h"
+#include "AX25Twist.h"
+
+// 1200Hz = -12dB, 2200Hz = 0dB; 3381Hz cutoff; cosine.
+q15_t dB12[] = {
+  176,
+  -812,
+  -3916,
+  -7586,
+  23536,
+  -7586,
+  -3916,
+  -812,
+  176
+};
+
+// 1200Hz = -11dB, 2200Hz = 0dB; 3258Hz cutoff; cosine.
+q15_t dB11[] = {
+  121,
+  -957,
+  -3959,
+  -7383,
+  23871,
+  -7383,
+  -3959,
+  -957,
+  121
+};
+
+// 1200Hz = -10dB, 2200Hz = 0dB; 3118Hz cutoff; cosine.
+q15_t dB10[] = {
+  56,
+  -1110,
+  -3987,
+  -7141,
+  24254,
+  -7141,
+  -3987,
+  -1110,
+  56
+};
+
+// 1200Hz = -9dB, 2200Hz = 0dB; 2959Hz cutoff; cosine.
+q15_t dB9[] = {
+  -19,
+  -1268,
+  -3994,
+  -6856,
+  24688,
+  -6856,
+  -3994,
+  -1268,
+  -19
+};
+
+// 1200Hz = -8dB, 2200Hz = 0dB; 2778Hz cutoff; cosine.
+q15_t dB8[] = {
+  -104,
+  -1424,
+  -3968,
+  -6516,
+  25182,
+  -6516,
+  -3968,
+  -1424,
+  -104
+};
+
+// 1200Hz = -7dB, 2200Hz = 0dB; 2573Hz cutoff; cosine.
+q15_t dB7[] = {
+  -196,
+  -1565,
+  -3896,
+  -6114,
+  25742,
+  -6114,
+  -3896,
+  -1565,
+  -196
+};
+
+// 1200Hz = -6dB, 2200Hz = 0dB; 2343Hz cutoff; cosine.
+q15_t dB6[] = {
+  -288,
+  -1676,
+  -3761,
+  -5642,
+  26370,
+  -5642,
+  -3761,
+  -1676,
+  -288
+};
+
+// 1200Hz = -5dB, 2200Hz = 0dB; 2085Hz cutoff; cosine.
+q15_t dB5[] = {
+  -370,
+  -1735,
+  -3545,
+  -5088,
+  27075,
+  -5088,
+  -3545,
+  -1735,
+  -370
+};
+
+// 1200Hz = -4dB, 2200Hz = 0dB; 1790Hz cutoff; cosine.
+q15_t dB4[] = {
+  -432,
+  -1715,
+  -3220,
+  -4427,
+  27880,
+  -4427,
+  -3220,
+  -1715,
+  -432
+};
+
+// 1200Hz = -3dB, 2200Hz = 0dB; 1456Hz cutoff; cosine.
+q15_t dB3[] = {
+  -452,
+  -1582,
+  -2759,
+  -3646,
+  28792,
+  -3646,
+  -2759,
+  -1582,
+  -452
+};
+
+// 1200Hz = -2dB, 2200Hz = 0dB; 1070Hz cutoff; cosine.
+q15_t dB2[] = {
+  -408,
+  -1295,
+  -2123,
+  -2710,
+  29846,
+  -2710,
+  -2123,
+  -1295,
+  -408
+};
+
+// 1200Hz = -1dB, 2200Hz = 0dB; 605Hz cutoff; cosine.
+q15_t dB1[] = {
+  -268,
+  -795,
+  -1244,
+  -1546,
+  31116,
+  -1546,
+  -1244,
+  -795,
+  -268
+};
+
+q15_t dB0[] = {
+  0,
+  0,
+  0,
+  0,
+  32767,
+  0,
+  0,
+  0,
+  0,
+};
+
+// 1200Hz = 0dB, 2200Hz = -1dB; 4130Hz cutoff; cosine.
+q15_t dB_1[] = {
+  -419,
+  -177,
+  3316,
+  8650,
+  11278,
+  8650,
+  3316,
+  -177,
+  -419
+};
+
+// 1200Hz = 0dB, 2200Hz = -2dB; 3190Hz cutoff; cosine.
+q15_t dB_2[] = {
+  -90,
+  1033,
+  3975,
+  7267,
+  8711,
+  7267,
+  3975,
+  1033,
+  -90
+};
+
+// 1200Hz = 0dB, 2200Hz = -3dB; 2330Hz cutoff; cosine.
+q15_t dB_3[] = {
+  292,
+  1680,
+  3752,
+  5615,
+  6362,
+  5615,
+  3752,
+  1680,
+  292
+};
+
+// 1200Hz = 0dB, 2200Hz = -4dB; 2657Hz cutoff; boxcar.
+q15_t dB_4[] = {
+  917,
+  3024,
+  5131,
+  6684,
+  7255,
+  6684,
+  5131,
+  3024,
+  917
+};
+
+// 1200Hz = 0dB, 2200Hz = -5dB; 2360Hz cutoff; boxcar.
+q15_t dB_5[] = {
+  1620,
+  3339,
+  4925,
+  6042,
+  6444,
+  6042,
+  4925,
+  3339,
+  1620
+};
+
+// 1200Hz = 0dB, 2200Hz = -6dB; 2067Hz cutoff; boxcar.
+q15_t dB_6[] = {
+  2161,
+  3472,
+  4605,
+  5373,
+  5644,
+  5373,
+  4605,
+  3472,
+  2161
+};
+
+q15_t* coeffs[] = {
+  dB12,
+  dB11,
+  dB10,
+  dB9,
+  dB8,
+  dB7,
+  dB6,
+  dB5,
+  dB4,
+  dB3,
+  dB2,
+  dB1,
+  dB0,
+  dB_1,
+  dB_2,
+  dB_3,
+  dB_4,
+  dB_5,
+  dB_6
+};
+
+CAX25Twist::CAX25Twist(int8_t n) :
+m_filter(),
+m_state()
+{
+  setTwist(n);
+}
+
+void CAX25Twist::process(q15_t* in, q15_t* out, uint8_t length)
+{
+  ::arm_fir_fast_q15(&m_filter, in, out, length);
+}
+
+void CAX25Twist::setTwist(int8_t n)
+{
+  uint8_t twist = uint8_t(n + 6);
+
+  m_filter.numTaps = 9;
+  m_filter.pState  = m_state;
+  m_filter.pCoeffs = coeffs[twist];
+}
+

AX25Twist.h

@@ -0,0 +1,39 @@
+/*
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#if !defined(AX25Twist_H)
+#define  AX25Twist_H
+
+#include "Config.h"
+
+
+class CAX25Twist {
+public:
+  CAX25Twist(int8_t n);
+
+  void process(q15_t* in, q15_t* out, uint8_t length);
+
+  void setTwist(int8_t n);
+
+private:
+  arm_fir_instance_q15 m_filter;
+  q15_t                m_state[40U];   // NoTaps + BlockSize - 1, 9 + 20 - 1 plus some spare
+};
+
+#endif
+

CWIdTX.cpp

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2017 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2017,2020 by Jonathan Naylor G4KLX
  *   Copyright (C) 2016 by Colin Durbridge G4EML
  *
  *   This program is free software; you can redistribute it and/or modify
@@ -125,7 +125,7 @@ void CCWIdTX::process()
   }
 }
 
-uint8_t CCWIdTX::write(const uint8_t* data, uint8_t length)
+uint8_t CCWIdTX::write(const uint8_t* data, uint16_t length)
 {
   ::memset(m_poBuffer, 0x00U, 1000U * sizeof(uint8_t));
 

CWIdTX.h

@@ -1,6 +1,6 @@
 /*
  *   Copyright (C) 2009-2015 by Jonathan Naylor G4KLX
- *   Copyright (C) 2016 by Colin Durbridge G4EML
+ *   Copyright (C) 2016,2020 by Colin Durbridge G4EML
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -28,7 +28,7 @@ public:
 
   void process();
 
-  uint8_t write(const uint8_t* data, uint8_t length);
+  uint8_t write(const uint8_t* data, uint16_t length);
 
   void reset();
 

CalDMR.cpp

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2015 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2015,2020 by Jonathan Naylor G4KLX
  *   Copyright (C) 2016 by Colin Durbridge G4EML
  *
  *   This program is free software; you can redistribute it and/or modify
@@ -208,7 +208,7 @@ void CCalDMR::dmrdmo1k()
   }
 }
 
-uint8_t CCalDMR::write(const uint8_t* data, uint8_t length)
+uint8_t CCalDMR::write(const uint8_t* data, uint16_t length)
 {
   if (length != 1U)
     return 4U;

CalDMR.h

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2015 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2015,2020 by Jonathan Naylor G4KLX
  *   Copyright (C) 2016 by Colin Durbridge G4EML
  *
  *   This program is free software; you can redistribute it and/or modify
@@ -41,7 +41,7 @@ public:
   void createData1k(uint8_t n);
   void createDataDMO1k(uint8_t n);
 
-  uint8_t write(const uint8_t* data, uint8_t length);
+  uint8_t write(const uint8_t* data, uint16_t length);
 
 private:
   bool      m_transmit;

CalDStarTX.cpp

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2016 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2016,2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -162,7 +162,7 @@ void CCalDStarTX::process()
   m_count = (m_count + 1U) % (30U * 21U);
 }
 
-uint8_t CCalDStarTX::write(const uint8_t* data, uint8_t length)
+uint8_t CCalDStarTX::write(const uint8_t* data, uint16_t length)
 {
   if (length != 1U)
     return 4U;

CalDStarTX.h

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2015,2016 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2015,2016,2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -26,7 +26,7 @@ class CCalDStarTX {
 public:
   CCalDStarTX();
 
-  uint8_t write(const uint8_t* data, uint8_t length);
+  uint8_t write(const uint8_t* data, uint16_t length);
 
   void process();
 

CalFM.cpp

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2015 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2015,2020 by Jonathan Naylor G4KLX
  *   Copyright (C) 2016 by Colin Durbridge G4EML
  *   Copyright (C) 2020 by Phil Taylor M0VSE
  *
@@ -52,7 +52,7 @@ void CCalFM::process()
 {
   const TONE_TABLE* entry = NULL;
 
-  if (m_modemState!=m_lastState)
+  if (m_modemState != m_lastState)
   {
     switch (m_modemState) {
         case STATE_FMCAL10K:
@@ -116,7 +116,7 @@ void CCalFM::process()
 }
 
 
-uint8_t CCalFM::write(const uint8_t* data, uint8_t length)
+uint8_t CCalFM::write(const uint8_t* data, uint16_t length)
 {
   if (length != 1U)
     return 4U;

CalFM.h

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2015 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2015,2020 by Jonathan Naylor G4KLX
  *   Copyright (C) 2016 by Colin Durbridge G4EML
  *   Copyright (C) 2020 by Phil Taylor M0VSE
  *
@@ -35,7 +35,7 @@ public:
   void fm25kcal();
   void fm30kcal();
 
-  uint8_t write(const uint8_t* data, uint8_t length);
+  uint8_t write(const uint8_t* data, uint16_t length);
 
 private:
   uint16_t  m_frequency;

CalNXDN.cpp

@@ -1,5 +1,6 @@
 /*
  *   Copyright (C) 2018 by Andy Uribe CA6JAU
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -79,7 +80,7 @@ void CCalNXDN::process()
   }
 }
 
-uint8_t CCalNXDN::write(const uint8_t* data, uint8_t length)
+uint8_t CCalNXDN::write(const uint8_t* data, uint16_t length)
 {
   if (length != 1U)
     return 4U;

CalNXDN.h

@@ -1,5 +1,6 @@
 /*
  *   Copyright (C) 2018 by Andy Uribe CA6JAU
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -32,7 +33,7 @@ public:
 
   void process();
 
-  uint8_t write(const uint8_t* data, uint8_t length);
+  uint8_t write(const uint8_t* data, uint16_t length);
 
 private:
   bool      m_transmit;

CalP25.cpp

@@ -1,5 +1,6 @@
 /*
  *   Copyright (C) 2018 by Andy Uribe CA6JAU
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -82,7 +83,7 @@ void CCalP25::process()
   }
 }
 
-uint8_t CCalP25::write(const uint8_t* data, uint8_t length)
+uint8_t CCalP25::write(const uint8_t* data, uint16_t length)
 {
   if (length != 1U)
     return 4U;

CalP25.h

@@ -1,5 +1,6 @@
 /*
  *   Copyright (C) 2018 by Andy Uribe CA6JAU
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -34,7 +35,7 @@ public:
 
   void process();
 
-  uint8_t write(const uint8_t* data, uint8_t length);
+  uint8_t write(const uint8_t* data, uint16_t length);
 
 private:
   bool      m_transmit;

CalPOCSAG.cpp

@@ -1,5 +1,6 @@
 /*
  *   Copyright (C) 2019 by Florian Wolters DF2ET
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -38,7 +39,7 @@ void CCalPOCSAG::process()
   pocsagTX.writeByte(0xAAU);
 }
 
-uint8_t CCalPOCSAG::write(const uint8_t* data, uint8_t length)
+uint8_t CCalPOCSAG::write(const uint8_t* data, uint16_t length)
 {
   if (length != 1U)
     return 4U;

CalPOCSAG.h

@@ -1,5 +1,6 @@
 /*
  *   Copyright (C) 2019 by Florian Wolters DF2ET
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -32,7 +33,7 @@ public:
 
   void process();
 
-  uint8_t write(const uint8_t* data, uint8_t length);
+  uint8_t write(const uint8_t* data, uint16_t length);
 
 private:
   POCSAGCAL m_state;

Config.h

@@ -35,8 +35,16 @@
 // For 19.2 MHz
 // #define EXTERNAL_OSC 19200000
 
+// Use a higher baudrate for host communication. Required for FM network !
+#define SERIAL_SPEED 115200 //suitable for most older boards (Arduino, Due STM32F1_POG etc). External FM will NOT work with this !
+// #define SERIAL_SPEED 230400 // Only works on newer board M4, M7, Teensy. External FM might work with this
+// #define SERIAL_SPEED 460800 // Only works on newer board M4, M7, Teensy. External FM should work with this
+
+// Allow the use of the COS line to lockout the modem
+// #define USE_COS_AS_LOCKOUT
+
 // Use pins to output the current mode via LEDs
-// #define MODE_LEDS
+#define MODE_LEDS
 
 // For the original Arduino Due pin layout
 // #define ARDUINO_DUE_PAPA
@@ -79,12 +87,13 @@
 // #define USE_ALTERNATE_NXDN_LEDS
 
 // Use the D-Star and P25 LEDs for M17
-// #define USE_ALTERNATE_M17_LEDS
+#define USE_ALTERNATE_M17_LEDS
 
 // Use the D-Star and DMR LEDs for POCSAG
-// #define USE_ALTERNATE_POCSAG_LEDS
+#define USE_ALTERNATE_POCSAG_LEDS
 
 // Use the D-Star and YSF LEDs for FM
 #define USE_ALTERNATE_FM_LEDS
 
 #endif
+

DMRDMOTX.cpp

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2017 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2017,2020 by Jonathan Naylor G4KLX
  *   Copyright (C) 2016 by Colin Durbridge G4EML
  *   Copyright (C) 2017 by Andy Uribe CA6JAU
  *
@@ -74,7 +74,7 @@ void CDMRDMOTX::process()
       m_poLen = m_txDelay;
     } else {
       for (unsigned int i = 0U; i < DMR_FRAME_LENGTH_BYTES; i++)
-        m_poBuffer[i] = m_fifo.get();
+        m_fifo.get(m_poBuffer[i]);
 
       for (unsigned int i = 0U; i < 39U; i++)
         m_poBuffer[i + DMR_FRAME_LENGTH_BYTES] = PR_FILL[i];
@@ -104,7 +104,7 @@ void CDMRDMOTX::process()
   }
 }
 
-uint8_t CDMRDMOTX::writeData(const uint8_t* data, uint8_t length)
+uint8_t CDMRDMOTX::writeData(const uint8_t* data, uint16_t length)
 {
   if (length != (DMR_FRAME_LENGTH_BYTES + 1U))
     return 4U;

DMRDMOTX.h

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2015,2016,2017 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2015,2016,2017,2020 by Jonathan Naylor G4KLX
  *   Copyright (C) 2016 by Colin Durbridge G4EML
  *
  *   This program is free software; you can redistribute it and/or modify
@@ -23,13 +23,13 @@
 #include "Config.h"
 #include "DMRDefines.h"
 
-#include "SerialRB.h"
+#include "RingBuffer.h"
 
 class CDMRDMOTX {
 public:
   CDMRDMOTX();
 
-  uint8_t writeData(const uint8_t* data, uint8_t length);
+  uint8_t writeData(const uint8_t* data, uint16_t length);
 
   void process();
 
@@ -38,7 +38,7 @@ public:
   uint8_t getSpace() const;
 
 private:
-  CSerialRB                        m_fifo;
+  CRingBuffer<uint8_t>                        m_fifo;
   arm_fir_interpolate_instance_q15 m_modFilter;
   q15_t                            m_modState[16U];    // blockSize + phaseLength - 1, 4 + 9 - 1 plus some spare
   uint8_t                          m_poBuffer[1200U];

DMRTX.cpp

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2017 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2017,2020 by Jonathan Naylor G4KLX
  *   Copyright (C) 2016 by Colin Durbridge G4EML
  *   Copyright (C) 2017 by Andy Uribe CA6JAU
  *
@@ -144,7 +144,7 @@ void CDMRTX::process()
   }
 }
 
-uint8_t CDMRTX::writeData1(const uint8_t* data, uint8_t length)
+uint8_t CDMRTX::writeData1(const uint8_t* data, uint16_t length)
 {
   if (length != (DMR_FRAME_LENGTH_BYTES + 1U))
     return 4U;
@@ -168,7 +168,7 @@ uint8_t CDMRTX::writeData1(const uint8_t* data, uint8_t length)
   return 0U;
 }
 
-uint8_t CDMRTX::writeData2(const uint8_t* data, uint8_t length)
+uint8_t CDMRTX::writeData2(const uint8_t* data, uint16_t length)
 {
   if (length != (DMR_FRAME_LENGTH_BYTES + 1U))
     return 4U;
@@ -192,7 +192,7 @@ uint8_t CDMRTX::writeData2(const uint8_t* data, uint8_t length)
   return 0U;
 }
 
-uint8_t CDMRTX::writeShortLC(const uint8_t* data, uint8_t length)
+uint8_t CDMRTX::writeShortLC(const uint8_t* data, uint16_t length)
 {
   if (length != 9U)
     return 4U;
@@ -208,7 +208,7 @@ uint8_t CDMRTX::writeShortLC(const uint8_t* data, uint8_t length)
   return 0U;
 }
 
-uint8_t CDMRTX::writeAbort(const uint8_t* data, uint8_t length)
+uint8_t CDMRTX::writeAbort(const uint8_t* data, uint16_t length)
 {
   if (length != 1U)
     return 4U;
@@ -293,7 +293,7 @@ void CDMRTX::createData(uint8_t slotIndex)
 {
   if (m_fifo[slotIndex].getData() >= DMR_FRAME_LENGTH_BYTES && m_frameCount >= STARTUP_COUNT && m_abortCount[slotIndex] >= ABORT_COUNT) {
     for (unsigned int i = 0U; i < DMR_FRAME_LENGTH_BYTES; i++) {
-      m_poBuffer[i]   = m_fifo[slotIndex].get();
+      m_fifo[slotIndex].get(m_poBuffer[i]);
       m_markBuffer[i] = MARK_NONE;
     }
   } else {

DMRTX.h

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2015,2016,2017 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2015,2016,2017,2020 by Jonathan Naylor G4KLX
  *   Copyright (C) 2016 by Colin Durbridge G4EML
  *
  *   This program is free software; you can redistribute it and/or modify
@@ -23,7 +23,7 @@
 #include "Config.h"
 #include "DMRDefines.h"
 
-#include "SerialRB.h"
+#include "RingBuffer.h"
 
 enum DMRTXSTATE {
   DMRTXSTATE_IDLE,
@@ -38,11 +38,11 @@ class CDMRTX {
 public:
   CDMRTX();
 
-  uint8_t writeData1(const uint8_t* data, uint8_t length);
+  uint8_t writeData1(const uint8_t* data, uint16_t length);
-  uint8_t writeData2(const uint8_t* data, uint8_t length);
+  uint8_t writeData2(const uint8_t* data, uint16_t length);
 
-  uint8_t writeShortLC(const uint8_t* data, uint8_t length);
+  uint8_t writeShortLC(const uint8_t* data, uint16_t length);
-  uint8_t writeAbort(const uint8_t* data, uint8_t length);
+  uint8_t writeAbort(const uint8_t* data, uint16_t length);
 
   void setStart(bool start);
   void setCal(bool start);
@@ -59,7 +59,7 @@ public:
   void setColorCode(uint8_t colorCode);
 
 private:
-  CSerialRB                        m_fifo[2U];
+  CRingBuffer<uint8_t>                        m_fifo[2U];
   arm_fir_interpolate_instance_q15 m_modFilter;
   q15_t                            m_modState[16U];    // blockSize + phaseLength - 1, 4 + 9 - 1 plus some spare
   DMRTXSTATE                       m_state;

DStarTX.cpp

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2017 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2017,2020 by Jonathan Naylor G4KLX
  *   Copyright (C) 2017 by Andy Uribe CA6JAU
  *
  *   This program is free software; you can redistribute it and/or modify
@@ -216,12 +216,13 @@ void CDStarTX::process()
       for (uint16_t i = 0U; i < m_txDelay; i++)
         m_poBuffer[m_poLen++] = BIT_SYNC;
     } else {
+      uint8_t dummy;
       // Pop the type byte off
-      m_buffer.get();
+      m_buffer.get(dummy);
 
       uint8_t header[DSTAR_HEADER_LENGTH_BYTES];
       for (uint8_t i = 0U; i < DSTAR_HEADER_LENGTH_BYTES; i++)
-        header[i] = m_buffer.get();
+        m_buffer.get(header[i]);
 
       uint8_t buffer[86U];
       txHeader(header, buffer + 2U);
@@ -239,17 +240,19 @@ void CDStarTX::process()
  
   if (type == DSTAR_DATA && m_poLen == 0U) {
     // Pop the type byte off
-    m_buffer.get();
+    uint8_t dummy;
+    m_buffer.get(dummy);
 
     for (uint8_t i = 0U; i < DSTAR_DATA_LENGTH_BYTES; i++)
-      m_poBuffer[m_poLen++] = m_buffer.get();
+      m_buffer.get(m_poBuffer[m_poLen++]);
 
     m_poPtr = 0U;
   }
 
   if (type == DSTAR_EOT && m_poLen == 0U) {
     // Pop the type byte off
-    m_buffer.get();
+    uint8_t dummy;
+    m_buffer.get(dummy);
 
     for (uint8_t j = 0U; j < 3U; j++) {
       for (uint8_t i = 0U; i < DSTAR_EOT_LENGTH_BYTES; i++)
@@ -277,7 +280,7 @@ void CDStarTX::process()
   }
 }
 
-uint8_t CDStarTX::writeHeader(const uint8_t* header, uint8_t length)
+uint8_t CDStarTX::writeHeader(const uint8_t* header, uint16_t length)
 {
   if (length != DSTAR_HEADER_LENGTH_BYTES)
     return 4U;
@@ -296,7 +299,7 @@ uint8_t CDStarTX::writeHeader(const uint8_t* header, uint8_t length)
   return 0U;
 }
 
-uint8_t CDStarTX::writeData(const uint8_t* data, uint8_t length)
+uint8_t CDStarTX::writeData(const uint8_t* data, uint16_t length)
 {
   if (length != DSTAR_DATA_LENGTH_BYTES)
     return 4U;

DStarTX.h

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2015,2016,2017 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2015,2016,2017,2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -21,14 +21,14 @@
 
 #include "Config.h"
 
-#include "SerialRB.h"
+#include "RingBuffer.h"
 
 class CDStarTX {
 public:
   CDStarTX();
 
-  uint8_t writeHeader(const uint8_t* header, uint8_t length);
+  uint8_t writeHeader(const uint8_t* header, uint16_t length);
-  uint8_t writeData(const uint8_t* data, uint8_t length);
+  uint8_t writeData(const uint8_t* data, uint16_t length);
   uint8_t writeEOT();
 
   void process();
@@ -38,7 +38,7 @@ public:
   uint8_t getSpace() const;
 
 private:
-  CSerialRB                        m_buffer;
+  CRingBuffer<uint8_t>             m_buffer;
   arm_fir_interpolate_instance_q15 m_modFilter;
   q15_t                            m_modState[20U];    // blockSize + phaseLength - 1, 8 + 9 - 1 plus some spare
   uint8_t                          m_poBuffer[600U];

FM.h

@@ -27,28 +27,33 @@
 #include "FMTimeout.h"
 #include "FMKeyer.h"
 #include "FMTimer.h"
-#include "FMRB.h"
+#include "RingBuffer.h"
 #include "FMDirectForm1.h"
-#include "FMDownsampler.h"
+#include "FMDownSampler.h"
+#include "FMUpSampler.h"
+#include "FMNoiseSquelch.h"
 
 enum FM_STATE {
   FS_LISTENING,
-  FS_KERCHUNK,
+  FS_KERCHUNK_RF,
-  FS_RELAYING,
+  FS_RELAYING_RF,
-  FS_RELAYING_WAIT,
+  FS_RELAYING_WAIT_RF,
-  FS_TIMEOUT,
+  FS_TIMEOUT_RF,
-  FS_TIMEOUT_WAIT,
+  FS_TIMEOUT_WAIT_RF,
+  FS_KERCHUNK_EXT,
+  FS_RELAYING_EXT,
+  FS_RELAYING_WAIT_EXT,
+  FS_TIMEOUT_EXT,
+  FS_TIMEOUT_WAIT_EXT,
   FS_HANG
 };
 
 
-
-
 class CFM {
 public:
   CFM();
 
-  void samples(bool cos, const q15_t* samples, uint8_t length);
+  void samples(bool cos, q15_t* samples, uint8_t length);
 
   void process();
 
@@ -56,13 +61,20 @@ public:
 
   uint8_t setCallsign(const char* callsign, uint8_t speed, uint16_t frequency, uint8_t time, uint8_t holdoff, uint8_t highLevel, uint8_t lowLevel, bool callsignAtStart, bool callsignAtEnd, bool callsignAtLatch);
   uint8_t setAck(const char* rfAck, uint8_t speed, uint16_t frequency, uint8_t minTime, uint16_t delay, uint8_t level);
-  uint8_t setMisc(uint16_t timeout, uint8_t timeoutLevel, uint8_t ctcssFrequency, uint8_t ctcssHighThreshold, uint8_t ctcssLowThreshold, uint8_t ctcssLevel, uint8_t kerchunkTime, uint8_t hangTime, uint8_t accessMode, bool cosInvert, uint8_t rfAudioBoost, uint8_t maxDev, uint8_t rxLevel);
+  uint8_t setMisc(uint16_t timeout, uint8_t timeoutLevel, uint8_t ctcssFrequency, uint8_t ctcssHighThreshold, uint8_t ctcssLowThreshold, uint8_t ctcssLevel, uint8_t kerchunkTime, uint8_t hangTime, uint8_t accessMode, bool cosInvert, bool noiseSquelch, uint8_t squelchHighThreshold, uint8_t squelchLowThreshold, uint8_t rfAudioBoost, uint8_t maxDev, uint8_t rxLevel);
+  uint8_t setExt(const char* ack, uint8_t audioBoost, uint8_t speed, uint16_t frequency, uint8_t level);
+
+  uint8_t getSpace() const;
+
+  uint8_t writeData(const uint8_t* data, uint8_t length);
 
 private:
   CFMKeyer             m_callsign;
   CFMKeyer             m_rfAck;
+  CFMKeyer             m_extAck;
   CFMCTCSSRX           m_ctcssRX;
   CFMCTCSSTX           m_ctcssTX;
+  CFMNoiseSquelch      m_squelch;
   CFMTimeout           m_timeoutTone;
   FM_STATE             m_state;
   bool                 m_callsignAtStart;
@@ -75,27 +87,51 @@ private:
   CFMTimer             m_ackMinTimer;
   CFMTimer             m_ackDelayTimer;
   CFMTimer             m_hangTimer;
+  CFMTimer             m_statusTimer;
   CFMTimer             m_reverseTimer;
+  bool                 m_needReverse;
   CFMDirectFormI       m_filterStage1;
   CFMDirectFormI       m_filterStage2;
   CFMDirectFormI       m_filterStage3;
   CFMBlanking          m_blanking;
   uint8_t              m_accessMode;
   bool                 m_cosInvert;
+  bool                 m_noiseSquelch;
   q15_t                m_rfAudioBoost;
-  CFMDownsampler       m_downsampler;
+  q15_t                m_extAudioBoost;
+  CFMDownSampler       m_downSampler;
+  bool                 m_extEnabled;
   q15_t                m_rxLevel;
-  CFMRB                m_inputRB;
+  CRingBuffer<q15_t>   m_inputRFRB;
-  CFMRB                m_outputRB;
+  CRingBuffer<q15_t>   m_outputRFRB;
+  CFMUpSampler         m_inputExtRB;
 
-  void stateMachine(bool validSignal);
+  void stateMachine(bool validRFSignal, bool validExtSignal);
-  void listeningState(bool validSignal);
+
-  void kerchunkState(bool validSignal);
+  void duplexStateMachine(bool validRFSignal, bool validExtSignal);
-  void relayingState(bool validSignal);
+  void listeningStateDuplex(bool validRFSignal, bool validExtSignal);
-  void relayingWaitState(bool validSignal);
+  void kerchunkRFStateDuplex(bool validSignal);
-  void timeoutState(bool validSignal);
+  void relayingRFStateDuplex(bool validSignal);
-  void timeoutWaitState(bool validSignal);
+  void relayingRFWaitStateDuplex(bool validSignal);
-  void hangState(bool validSignal);
+  void timeoutRFStateDuplex(bool validSignal);
+  void timeoutRFWaitStateDuplex(bool validSignal);
+  void kerchunkExtStateDuplex(bool validSignal);
+  void relayingExtStateDuplex(bool validSignal);
+  void relayingExtWaitStateDuplex(bool validSignal);
+  void timeoutExtStateDuplex(bool validSignal);
+  void timeoutExtWaitStateDuplex(bool validSignal);
+  void hangStateDuplex(bool validRFSignal, bool validExtSignal);
+
+  void simplexStateMachine(bool validRFSignal, bool validExtSignal);
+  void listeningStateSimplex(bool validRFSignal, bool validExtSignal);
+  void relayingRFStateSimplex(bool validSignal);
+  void relayingRFWaitStateSimplex(bool validSignal);
+  void timeoutRFStateSimplex(bool validSignal);
+  void timeoutRFWaitStateSimplex(bool validSignal);
+  void relayingExtStateSimplex(bool validSignal);
+  void relayingExtWaitStateSimplex(bool validSignal);
+  void timeoutExtStateSimplex(bool validSignal);
+  void timeoutExtWaitStateSimplex(bool validSignal);
 
   void clock(uint8_t length);
 

FMCTCSSRX.cpp

@@ -87,7 +87,7 @@ m_lowThreshold(0),
 m_count(0U),
 m_q0(0),
 m_q1(0),
-m_result(CTS_NONE)
+m_state(false)
 {
 }
 
@@ -111,13 +111,11 @@ uint8_t CFMCTCSSRX::setParams(uint8_t frequency, uint8_t highThreshold, uint8_t
   return 0U;
 }
 
-uint8_t CFMCTCSSRX::process(q15_t sample)
+bool CFMCTCSSRX::process(q15_t sample)
 {
   //get more dynamic into the decoder by multiplying the sample by 1.5
   q31_t sample31 = q31_t(sample) +  (q31_t(sample) >> 1);
 
-  m_result &= ~CTS_READY;
-
   q31_t q2 = m_q1;
   m_q1 = m_q0;
 
@@ -149,33 +147,29 @@ uint8_t CFMCTCSSRX::process(q15_t sample)
     // value = m_q0 * m_q0 + m_q1 * m_q1 - m_q0 * m_q1 * m_coeffDivTwo * 2
     q31_t value = t2 + t4 - t9;
 
-    bool previousCTCSSValid = CTCSS_VALID(m_result);
+    bool previousState = m_state;
 
     q31_t threshold = m_highThreshold;
-    if (previousCTCSSValid)
+    if (previousState)
       threshold = m_lowThreshold;
 
-    m_result |= CTS_READY;
+    m_state = value >= threshold;
-    if (value >= threshold)
-      m_result |= CTS_VALID;
-    else
-      m_result &= ~CTS_VALID;
 
-    if (previousCTCSSValid != CTCSS_VALID(m_result))
+    if (previousState != m_state)
-      DEBUG4("CTCSS Value / Threshold / Valid", value, threshold, CTCSS_VALID(m_result));
+      DEBUG4("CTCSS Value / Threshold / Valid", value, threshold, m_state);
 
     m_count = 0U;
     m_q0 = 0;
     m_q1 = 0;
   }
 
-  return m_result;
+  return m_state;
 }
 
 void CFMCTCSSRX::reset()
 {
   m_q0 = 0;
   m_q1 = 0;
-  m_result = CTS_NONE;
+  m_state = false;
   m_count = 0U;
 }

FMCTCSSRX.h

@@ -21,22 +21,13 @@
 
 #include "Config.h"
 
-const uint8_t CTS_NONE  = 0U;
-const uint8_t CTS_READY = 1U;
-const uint8_t CTS_VALID = 2U;
-
-#define CTCSS_READY(a) ((a & CTS_READY) != 0)
-#define CTCSS_NOT_READY(a) ((a & CTS_READY) == 0)
-#define CTCSS_VALID(a) ((a & CTS_VALID) != 0)
-#define CTCSS_NOT_VALID(a) ((a & CTS_VALID) == 0)
-
 class CFMCTCSSRX {
 public:
   CFMCTCSSRX();
 
   uint8_t setParams(uint8_t frequency, uint8_t highThreshold, uint8_t lowThreshold);
   
-  uint8_t process(q15_t sample);
+  bool process(q15_t sample);
 
   void reset();
 
@@ -47,7 +38,7 @@ private:
   uint16_t m_count;
   q31_t    m_q0;
   q31_t    m_q1;
-  uint8_t  m_result;
+  bool     m_state;
 };
 
 #endif

FMDirectForm1.h

@@ -29,7 +29,7 @@ THE SOFTWARE.
 
 // based on https://raw.githubusercontent.com/berndporr/iir_fixed_point/master/DirectFormI.h
 
-#include "Globals.h"
+#include <cstdint>
 
 #ifndef DIRECTFORMI_H_
 #define DIRECTFORMI_H_

FMDownSampler.cpp

@@ -0,0 +1,74 @@
+/*
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2020 by Geoffrey Merck F4FXL - KC3FRA
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "Config.h"
+#include "FMDownSampler.h"
+
+CFMDownSampler::CFMDownSampler(uint16_t length) :
+m_ringBuffer(length),
+m_samplePack(0U),
+m_samplePackPointer(NULL),
+m_sampleIndex(0U)
+{
+  m_samplePackPointer = (uint8_t*)&m_samplePack;
+}
+
+void CFMDownSampler::addSample(q15_t sample)
+{
+  uint32_t usample = uint32_t(int32_t(sample) + 2048);
+  //only take one of three samples
+  switch(m_sampleIndex){
+    case 0:
+      m_samplePack = usample << 12;
+    break;
+    case 3:{
+      m_samplePack |= usample;
+      
+      //we did not use MSB; skip it
+      TSamplePairPack pair{m_samplePackPointer[0U], m_samplePackPointer[1U], m_samplePackPointer[2U]}; 
+
+      m_ringBuffer.put(pair);
+
+      m_samplePack = 0U;//reset the sample pack
+    }
+    break;
+    default:
+        //Just skip this sample
+    break;
+  }
+
+  m_sampleIndex++;
+  if (m_sampleIndex >= 6U)//did we pack two samples ?
+      m_sampleIndex = 0U;  
+}
+
+bool CFMDownSampler::getPackedData(TSamplePairPack& data)
+{
+  return m_ringBuffer.get(data);
+}
+
+uint16_t CFMDownSampler::getData()
+{
+  return m_ringBuffer.getData();
+}
+
+void CFMDownSampler::reset()
+{
+  m_sampleIndex = 0U;
+}

FMDownSampler.h

@@ -21,23 +21,27 @@
 #define FMDOWNSAMPLER_H
 
 #include "Config.h"
-#include "FMDownsampleRB.h"
+#include "RingBuffer.h"
+#include "FMSamplePairPack.h"
 
-class CFMDownsampler {
+class CFMDownSampler {
 public:
-  CFMDownsampler(uint16_t length);
+  CFMDownSampler(uint16_t length);
+
   void addSample(q15_t sample);
-  inline bool getPackedData(uint8_t& data){ return m_ringBuffer.get(data); };
+
-  inline bool hasOverflowed() { return m_ringBuffer.hasOverflowed(); };
+  bool getPackedData(TSamplePairPack& data);
+
+  uint16_t getData();
+
+  void reset();
 
 private:
-  CFMDownsampleRB m_ringBuffer;
+  CRingBuffer<TSamplePairPack> m_ringBuffer;
-  union {
+  uint32_t                     m_samplePack;
-    int32_t m_samplePack;
+  uint8_t*                     m_samplePackPointer;
-    int8_t  m_samplePackBytes[4];
+  uint8_t                      m_sampleIndex;
-  };
-  uint8_t m_packIndex;
-  uint8_t m_downSampleIndex;
 };
 
 #endif
+

FMDownsampler.cpp

@@ -1,63 +0,0 @@
-/*
- *   Copyright (C) 2020 by Jonathan Naylor G4KLX
- *   Copyright (C) 2020 by Geoffrey Merck F4FXL - KC3FRA
- *
- *   This program is free software; you can redistribute it and/or modify
- *   it under the terms of the GNU General Public License as published by
- *   the Free Software Foundation; either version 2 of the License, or
- *   (at your option) any later version.
- *
- *   This program is distributed in the hope that it will be useful,
- *   but WITHOUT ANY WARRANTY; without even the implied warranty of
- *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *   GNU General Public License for more details.
- *
- *   You should have received a copy of the GNU General Public License
- *   along with this program; if not, write to the Free Software
- *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
- */
-
-#include "Config.h"
-#include "FMDownsampler.h"
-
-
-CFMDownsampler::CFMDownsampler(uint16_t length) :
-m_ringBuffer(length),//length might need tweaking
-m_packIndex(0),
-m_downSampleIndex(0)
-{
-    m_samplePack = 0;
-}
-
-void CFMDownsampler::addSample(q15_t sample)
-{
-    //only take one of three samples
-    if(m_downSampleIndex == 0) {
-      switch(m_packIndex){
-        case 0:
-          m_samplePack = int32_t(sample) << 12;
-        break;
-        case 1:{
-            m_samplePack |= int32_t(sample);
-            
-            //we did not use MSB; skip it
-            m_ringBuffer.put(m_samplePackBytes[1]); 
-            m_ringBuffer.put(m_samplePackBytes[2]); 
-            m_ringBuffer.put(m_samplePackBytes[3]); 
-
-            m_samplePack = 0;
-        }
-        break;
-        default:
-            //should never happen
-        break;
-        }
-        m_packIndex++;
-        if(m_packIndex >= 2)
-            m_packIndex = 0;  
-    }
-
-    m_downSampleIndex++;
-    if(m_downSampleIndex >= 3)
-        m_downSampleIndex = 0;
-}

FMNoiseSquelch.cpp

@@ -0,0 +1,127 @@
+/*
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "Config.h"
+#include "Globals.h"
+#include "FMNoiseSquelch.h"
+
+// 4500Hz centre frequency
+const q31_t COEFF_DIV_TWO = 821806413;
+
+// 400Hz bandwidth
+const uint16_t N = 24000U / 400U;
+
+CFMNoiseSquelch::CFMNoiseSquelch() :
+m_highThreshold(0),
+m_lowThreshold(0),
+m_count(0U),
+m_q0(0),
+m_q1(0),
+m_state(false),
+m_validCount(0U)
+{
+
+}
+
+void CFMNoiseSquelch::setParams(uint8_t highThreshold, uint8_t lowThreshold)
+{
+  m_highThreshold = q31_t(highThreshold);
+  m_lowThreshold  = q31_t(lowThreshold);
+}
+
+bool CFMNoiseSquelch::process(q15_t sample)
+{
+  //get more dynamic into the decoder by multiplying the sample by 64
+  q31_t sample31 = q31_t(sample) << 6; //+  (q31_t(sample) >> 1);
+
+  q31_t q2 = m_q1;
+  m_q1 = m_q0;
+
+  // Q31 multiplication, t3 = m_coeffDivTwo * 2 * m_q1
+  q63_t t1 = COEFF_DIV_TWO * m_q1;
+  q31_t t2 = __SSAT((t1 >> 31), 31);
+  q31_t t3 = t2 * 2;
+
+  // m_q0 = m_coeffDivTwo * m_q1 * 2 - q2 + sample
+  m_q0 = t3 - q2 + sample31;
+
+  m_count++;
+  if (m_count == N) {
+    // Q31 multiplication, t2 = m_q0 * m_q0
+    q63_t t1 = q63_t(m_q0) * q63_t(m_q0);
+    q31_t t2 = __SSAT((t1 >> 31), 31);
+
+    // Q31 multiplication, t4 = m_q0 * m_q0
+    q63_t t3 = q63_t(m_q1) * q63_t(m_q1);
+    q31_t t4 = __SSAT((t3 >> 31), 31);
+
+    // Q31 multiplication, t9 = m_q0 * m_q1 * m_coeffDivTwo * 2
+    q63_t t5 = q63_t(m_q0) * q63_t(m_q1);
+    q31_t t6 = __SSAT((t5 >> 31), 31);
+    q63_t t7 = t6 * COEFF_DIV_TWO;
+    q31_t t8 = __SSAT((t7 >> 31), 31);
+    q31_t t9  = t8 * 2;
+
+    // value = m_q0 * m_q0 + m_q1 * m_q1 - m_q0 * m_q1 * m_coeffDivTwo * 2
+    q31_t value = t2 + t4 - t9;
+
+    bool previousState = m_state;
+
+    q31_t threshold = m_highThreshold;
+    if (previousState)
+      threshold = m_lowThreshold;
+
+    if (!m_state) {
+      if (value < threshold)
+        m_validCount++;
+      else
+        m_validCount = 0U;
+    }
+
+    if (m_state) {
+      if (value >= threshold)
+        m_invalidCount++;
+      else
+        m_invalidCount = 0U;
+    }
+
+    m_state = m_validCount >= 10U && m_invalidCount < 10U;
+
+    if(previousState && !m_state)
+      m_invalidCount = 0U;
+
+    if (previousState != m_state) {
+      DEBUG4("Noise Squelch Value / Threshold / Valid", value, threshold, m_state);
+      DEBUG3("Valid Count / Invalid Count", m_validCount, m_invalidCount);
+    }
+
+    m_count = 0U;
+    m_q0 = 0;
+    m_q1 = 0;
+  }
+
+  return m_state;
+}
+
+void CFMNoiseSquelch::reset()
+{
+  m_q0 = 0;
+  m_q1 = 0;
+  m_state = false;
+  m_count = 0U;
+}

FMNoiseSquelch.h

@@ -0,0 +1,45 @@
+/*
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#if !defined(FMNOISESQUELCH_H)
+#define  FMNOISESQUELCH_H
+
+#include "Config.h"
+
+class CFMNoiseSquelch {
+public:
+  CFMNoiseSquelch();
+
+  void setParams(uint8_t highThreshold, uint8_t lowThreshold);
+  
+  bool process(q15_t sample);
+
+  void reset();
+
+private:
+  q31_t    m_highThreshold;
+  q31_t    m_lowThreshold;
+  uint16_t m_count;
+  q31_t    m_q0;
+  q31_t    m_q1;
+  bool     m_state;
+  uint8_t  m_validCount;
+  uint8_t  m_invalidCount;
+};
+
+#endif

FMRB.cpp

@@ -1,110 +0,0 @@
-/*
-TX fifo control - Copyright (C) KI6ZUM 2015
-Copyright (C) 2015,2016,2020 by Jonathan Naylor G4KLX
-
-This library is free software; you can redistribute it and/or
-modify it under the terms of the GNU Library General Public
-License as published by the Free Software Foundation; either
-version 2 of the License, or (at your option) any later version.
-
-This library is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-Library General Public License for more details.
-
-You should have received a copy of the GNU Library General Public
-License along with this library; if not, write to the
-Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
-Boston, MA  02110-1301, USA.
-*/
-
-#include "FMRB.h"
-
-CFMRB::CFMRB(uint16_t length) :
-m_length(length),
-m_head(0U),
-m_tail(0U),
-m_full(false),
-m_overflow(false)
-{
-  m_samples = new q15_t[length];
-}
-
-uint16_t CFMRB::getSpace() const
-{
-  uint16_t n = 0U;
-
-  if (m_tail == m_head)
-    n = m_full ? 0U : m_length;
-  else if (m_tail < m_head)
-    n = m_length - m_head + m_tail;
-  else
-    n = m_tail - m_head;
-
-  if (n > m_length)
-    n = 0U;
-
-  return n;
-}
-
-uint16_t CFMRB::getData() const
-{
-  if (m_tail == m_head)
-    return m_full ? m_length : 0U;
-  else if (m_tail < m_head)
-    return m_head - m_tail;
-  else
-    return m_length - m_tail + m_head;
-}
-
-bool CFMRB::put(q15_t sample)
-{
-  if (m_full) {
-    m_overflow = true;
-    return false;
-  }
-
-  m_samples[m_head] = sample;
-
-  m_head++;
-  if (m_head >= m_length)
-    m_head = 0U;
-
-  if (m_head == m_tail)
-    m_full = true;
-
-  return true;
-}
-
-bool CFMRB::get(q15_t& sample)
-{
-  if (m_head == m_tail && !m_full)
-    return false;
-
-  sample = m_samples[m_tail];
-
-  m_full = false;
-
-  m_tail++;
-  if (m_tail >= m_length)
-    m_tail = 0U;
-
-  return true;
-}
-
-bool CFMRB::hasOverflowed()
-{
-  bool overflow = m_overflow;
-
-  m_overflow = false;
-
-  return overflow;
-}
-
-void CFMRB::reset()
-{
-  m_head = 0U;
-  m_tail = 0U;
-  m_full     = false;
-  m_overflow = false;
-}

FMRB.h

@@ -1,72 +0,0 @@
-/*
-Serial fifo control - Copyright (C) KI6ZUM 2015
-Copyright (C) 2015,2016,2020 by Jonathan Naylor G4KLX
-
-This library is free software; you can redistribute it and/or
-modify it under the terms of the GNU Library General Public
-License as published by the Free Software Foundation; either
-version 2 of the License, or (at your option) any later version.
-
-This library is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-Library General Public License for more details.
-
-You should have received a copy of the GNU Library General Public
-License along with this library; if not, write to the
-Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
-Boston, MA  02110-1301, USA.
-*/
-
-#if !defined(FMRB_H)
-#define  FMRB_H
-
-#if defined(STM32F4XX)
-#include "stm32f4xx.h"
-#elif defined(STM32F7XX)
-#include "stm32f7xx.h"
-#elif defined(STM32F105xC)
-#include "stm32f1xx.h"
-#include <cstddef>
-#else
-#include <Arduino.h>
-#endif
-
-#if defined(__SAM3X8E__) || defined(STM32F105xC)
-#define  ARM_MATH_CM3
-#elif defined(STM32F7XX)
-#define  ARM_MATH_CM7
-#elif defined(STM32F4XX) || defined(__MK20DX256__) || defined(__MK64FX512__) || defined(__MK66FX1M0__)
-#define  ARM_MATH_CM4
-#else
-#error "Unknown processor type"
-#endif
-
-#include <arm_math.h>
-
-class CFMRB {
-public:
-  CFMRB(uint16_t length);
-  
-  uint16_t getSpace() const;
-  
-  uint16_t getData() const;
-
-  bool put(q15_t sample);
-
-  bool get(q15_t& sample);
-
-  bool hasOverflowed();
-
-  void reset();
-
-private:
-  uint16_t          m_length;
-  volatile q15_t*   m_samples;
-  volatile uint16_t m_head;
-  volatile uint16_t m_tail;
-  volatile bool     m_full;
-  bool              m_overflow;
-};
-
-#endif

FMSamplePairPack.h

@@ -0,0 +1,29 @@
+/*
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2020 by Geoffrey Merck F4FXL - KC3FRA
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#if !defined(TSAMPLEPACK_H)
+#define TSAMPLEPACK_H
+
+struct TSamplePairPack {
+  uint8_t byte0;
+  uint8_t byte1;
+  uint8_t byte2;
+};
+
+#endif

FMUpSampler.cpp

@@ -0,0 +1,97 @@
+/*
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2020 by Geoffrey Merck F4FXL - KC3FRA
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include "FMUpSampler.h"
+
+const uint32_t FM_UPSAMPLE_MASK = 0x00000FFFU;
+
+CFMUpSampler::CFMUpSampler() :
+m_upSampleIndex(0),
+m_pack(0U),
+m_packPointer(NULL),
+m_samples(3600U), //300ms of 12 bit 8kHz audio
+m_running(false)
+{
+  m_packPointer = (uint8_t*)&m_pack;
+}
+
+void CFMUpSampler::reset()
+{
+    m_upSampleIndex = 0U;
+    m_pack = 0U;
+    m_samples.reset();
+    m_running = false;
+}
+
+void CFMUpSampler::addData(const uint8_t* data, uint16_t length)
+{
+  TSamplePairPack* packPointer = (TSamplePairPack*)data;
+  TSamplePairPack* packPointerEnd = packPointer + (length / 3U);
+  while(packPointer != packPointerEnd) {
+    m_samples.put(*packPointer);
+    packPointer++;
+  }
+  if(!m_running)
+    m_running = m_samples.getData() > 300U;//75ms of audio
+}
+
+bool CFMUpSampler::getSample(q15_t& sample)
+{
+  if(!m_running)
+    return false;
+
+  switch (m_upSampleIndex)
+  {
+  case 0: {
+    TSamplePairPack pairPack;
+    if(!m_samples.get(pairPack)) {
+      m_running = false;
+      return false;
+    }
+      
+    m_pack = 0U;
+    m_packPointer = (uint8_t*)&m_pack;
+
+    m_packPointer[0U] = pairPack.byte0;
+    m_packPointer[1U] = pairPack.byte1;
+    m_packPointer[2U] = pairPack.byte2;
+
+    sample = q15_t(m_pack >> 12) - 2048;
+    break;
+  }
+  case 3:
+    sample = q15_t(m_pack & FM_UPSAMPLE_MASK) - 2048;
+  break;
+  default:
+    sample = 0;
+  break;
+  }
+
+  m_upSampleIndex++;
+  if(m_upSampleIndex >= 6U)
+    m_upSampleIndex = 0U;
+
+  return true;
+}
+
+uint16_t CFMUpSampler::getSpace() const
+{
+  //return available space in bytes
+  return m_samples.getSpace() * sizeof(TSamplePairPack);
+}

FMUpSampler.h

@@ -0,0 +1,48 @@
+/*
+ *   Copyright (C) 2020 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2020 by Geoffrey Merck F4FXL - KC3FRA
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+
+#if !defined(FMUPSAMPLER_H)
+#define FMUPSAMPLER_H
+
+#include "Config.h"
+#include "RingBuffer.h"
+#include "FMSamplePairPack.h"
+
+class CFMUpSampler {
+public:
+  CFMUpSampler();
+
+  void reset();
+
+  void addData(const uint8_t* data, uint16_t length);
+
+  bool getSample(q15_t& sample);
+
+  uint16_t getSpace() const;
+
+private:
+  uint8_t m_upSampleIndex;
+  uint32_t m_pack;
+  uint8_t * m_packPointer;
+  CRingBuffer<TSamplePairPack> m_samples;
+  bool m_running;
+};
+
+#endif

Globals.h

@@ -28,6 +28,7 @@
 #include "STM32Utils.h"
 #else
 #include <Arduino.h>
+#undef PI //Undefine PI to get rid of annoying warning as it is also defined in arm_math.h.
 #endif
 
 #if defined(__SAM3X8E__) || defined(STM32F105xC)
@@ -52,6 +53,7 @@ enum MMDVM_STATE {
   STATE_POCSAG    = 6,
   STATE_M17       = 7,
   STATE_FM        = 10,
+  STATE_AX25      = 11,
 
   // Dummy states start at 90
   STATE_NXDNCAL1K = 91,
@@ -99,6 +101,8 @@ enum MMDVM_STATE {
 #include "CalPOCSAG.h"
 #include "CalRSSI.h"
 #include "CWIdTX.h"
+#include "AX25RX.h"
+#include "AX25TX.h"
 #include "Debug.h"
 #include "IO.h"
 #include "FM.h"
@@ -128,6 +132,7 @@ extern bool m_nxdnEnable;
 extern bool m_pocsagEnable;
 extern bool m_m17Enable;
 extern bool m_fmEnable;
+extern bool m_ax25Enable;
 
 extern bool m_duplex;
 
@@ -163,6 +168,9 @@ extern CM17TX m17TX;
 
 extern CFM     fm;
 
+extern CAX25RX ax25RX;
+extern CAX25TX ax25TX;
+
 extern CCalDStarRX calDStarRX;
 extern CCalDStarTX calDStarTX;
 extern CCalDMR     calDMR;
@@ -175,3 +183,4 @@ extern CCalRSSI    calRSSI;
 extern CCWIdTX cwIdTX;
 
 #endif
+

IO.cpp

@@ -90,6 +90,7 @@ m_nxdnTXLevel(128 * 128),
 m_m17TXLevel(128 * 128),
 m_pocsagTXLevel(128 * 128),
 m_fmTXLevel(128 * 128),
+m_ax25TXLevel(128 * 128),
 m_rxDCOffset(DC_OFFSET),
 m_txDCOffset(DC_OFFSET),
 m_useCOSAsLockout(false),
@@ -306,6 +307,7 @@ void CIO::process()
   if (m_txBuffer.getData() == 0U && m_tx) {
     m_tx = false;
     setPTTInt(m_pttInvert ? true : false);
+    DEBUG1("TX OFF");
   }
 
   if (m_rxBuffer.getData() >= RX_BLOCK_SIZE) {
@@ -314,15 +316,16 @@ void CIO::process()
     uint16_t rssi[RX_BLOCK_SIZE];
 
     for (uint16_t i = 0U; i < RX_BLOCK_SIZE; i++) {
-      uint16_t sample;
+      TSample sample;
-      m_rxBuffer.get(sample, control[i]);
+      m_rxBuffer.get(sample);
+      control[i] = sample.control;
       m_rssiBuffer.get(rssi[i]);
 
       // Detect ADC overflow
-      if (m_detect && (sample == 0U || sample == 4095U))
+      if (m_detect && (sample.sample == 0U || sample.sample == 4095U))
         m_adcOverflow++;
 
-      q15_t res1 = q15_t(sample) - m_rxDCOffset;
+      q15_t res1 = q15_t(sample.sample) - m_rxDCOffset;
       q31_t res2 = res1 * m_rxLevel;
       samples[i] = q15_t(__SSAT((res2 >> 15), 16));
     }
@@ -419,6 +422,14 @@ void CIO::process()
         fm.samples(cos, dcSamples, RX_BLOCK_SIZE);
 #else
         fm.samples(cos, samples, RX_BLOCK_SIZE);
+#endif
+      }
+
+      if (m_ax25Enable) {
+#if defined(USE_DCBLOCKER)
+        ax25RX.samples(dcSamples, RX_BLOCK_SIZE);
+#else
+        ax25RX.samples(samples, RX_BLOCK_SIZE);
 #endif
       }
     } else if (m_modemState == STATE_DSTAR) {
@@ -493,8 +504,12 @@ void CIO::process()
       bool cos = getCOSInt();
 #if defined(USE_DCBLOCKER)
       fm.samples(cos, dcSamples, RX_BLOCK_SIZE);
+      if (m_ax25Enable)
+        ax25RX.samples(dcSamples, RX_BLOCK_SIZE);
 #else
       fm.samples(cos, samples, RX_BLOCK_SIZE);
+      if (m_ax25Enable)
+        ax25RX.samples(samples, RX_BLOCK_SIZE);
 #endif
     } else if (m_modemState == STATE_DSTARCAL) {
       q15_t GMSKVals[RX_BLOCK_SIZE];
@@ -519,6 +534,7 @@ void CIO::write(MMDVM_STATE mode, q15_t* samples, uint16_t length, const uint8_t
   if (!m_tx) {
     m_tx = true;
     setPTTInt(m_pttInvert ? false : true);
+    DEBUG1("TX ON");
   }
 
   q15_t txLevel = 0;
@@ -547,6 +563,9 @@ void CIO::write(MMDVM_STATE mode, q15_t* samples, uint16_t length, const uint8_t
     case STATE_FM:
       txLevel = m_fmTXLevel;
       break;
+    case STATE_AX25:
+      txLevel = m_ax25TXLevel;
+      break;
     default:
       txLevel = m_cwIdTXLevel;
       break;
@@ -562,9 +581,9 @@ void CIO::write(MMDVM_STATE mode, q15_t* samples, uint16_t length, const uint8_t
       m_dacOverflow++;
 
     if (control == NULL)
-      m_txBuffer.put(res3, MARK_NONE);
+      m_txBuffer.put({res3, MARK_NONE});
     else
-      m_txBuffer.put(res3, control[i]);
+      m_txBuffer.put({res3, control[i]});
   }
 }
 
@@ -618,7 +637,7 @@ void CIO::setMode(MMDVM_STATE state)
   m_modemState = state;
 }
 
-void CIO::setParameters(bool rxInvert, bool txInvert, bool pttInvert, uint8_t rxLevel, uint8_t cwIdTXLevel, uint8_t dstarTXLevel, uint8_t dmrTXLevel, uint8_t ysfTXLevel, uint8_t p25TXLevel, uint8_t nxdnTXLevel, uint8_t m17TXLevel, uint8_t pocsagTXLevel, uint8_t fmTXLevel, int16_t txDCOffset, int16_t rxDCOffset, bool useCOSAsLockout)
+void CIO::setParameters(bool rxInvert, bool txInvert, bool pttInvert, uint8_t rxLevel, uint8_t cwIdTXLevel, uint8_t dstarTXLevel, uint8_t dmrTXLevel, uint8_t ysfTXLevel, uint8_t p25TXLevel, uint8_t nxdnTXLevel, uint8_t m17TXLevel, uint8_t pocsagTXLevel, uint8_t fmTXLevel, uint8_t ax25TXLevel, int16_t txDCOffset, int16_t rxDCOffset, bool useCOSAsLockout)
 {
   m_pttInvert = pttInvert;
 
@@ -632,6 +651,7 @@ void CIO::setParameters(bool rxInvert, bool txInvert, bool pttInvert, uint8_t rx
   m_m17TXLevel    = q15_t(m17TXLevel * 128);
   m_pocsagTXLevel = q15_t(pocsagTXLevel * 128);
   m_fmTXLevel     = q15_t(fmTXLevel * 128);
+  m_ax25TXLevel   = q15_t(ax25TXLevel * 128);
 
   m_rxDCOffset   = DC_OFFSET + rxDCOffset;
   m_txDCOffset   = DC_OFFSET + txDCOffset;

IO.h

@@ -21,8 +21,12 @@
 
 #include "Globals.h"
 
-#include "SampleRB.h"
+#include "RingBuffer.h"
-#include "RSSIRB.h"
+
+struct TSample {
+  volatile uint16_t sample;
+  volatile uint8_t control;
+};
 
 class CIO {
 public:
@@ -42,7 +46,7 @@ public:
   
   void interrupt();
 
-  void setParameters(bool rxInvert, bool txInvert, bool pttInvert, uint8_t rxLevel, uint8_t cwIdTXLevel, uint8_t dstarTXLevel, uint8_t dmrTXLevel, uint8_t ysfTXLevel, uint8_t p25TXLevel, uint8_t nxdnTXLevel, uint8_t m17TXLevel, uint8_t pocsagTXLevel, uint8_t fmTXLevel, int16_t txDCOffset, int16_t rxDCOffset, bool useCOSAsLockout);
+  void setParameters(bool rxInvert, bool txInvert, bool pttInvert, uint8_t rxLevel, uint8_t cwIdTXLevel, uint8_t dstarTXLevel, uint8_t dmrTXLevel, uint8_t ysfTXLevel, uint8_t p25TXLevel, uint8_t nxdnTXLevel, uint8_t m17TXLevel, uint8_t pocsagTXLevel, uint8_t fmTXLevel, uint8_t ax25TXLevel, int16_t txDCOffset, int16_t rxDCOffset, bool useCOSAsLockout);
 
   void getOverflow(bool& adcOverflow, bool& dacOverflow);
 
@@ -59,9 +63,9 @@ public:
 private:
   bool                  m_started;
 
-  CSampleRB            m_rxBuffer;
+  CRingBuffer<TSample>  m_rxBuffer;
-  CSampleRB            m_txBuffer;
+  CRingBuffer<TSample>  m_txBuffer;
-  CRSSIRB              m_rssiBuffer;
+  CRingBuffer<uint16_t> m_rssiBuffer;
 
   arm_biquad_casd_df1_inst_q31 m_dcFilter;
   q31_t                        m_dcState[4];
@@ -90,6 +94,7 @@ private:
   q15_t                m_m17TXLevel;
   q15_t                m_pocsagTXLevel;
   q15_t                m_fmTXLevel;
+  q15_t                m_ax25TXLevel;
 
   uint16_t             m_rxDCOffset;
   uint16_t             m_txDCOffset;

IODue.cpp

@@ -188,14 +188,13 @@ void CIO::startInt()
 void CIO::interrupt()
 {
   if ((ADC->ADC_ISR & ADC_ISR_EOC_Chan) == ADC_ISR_EOC_Chan) {    // Ensure there was an End-of-Conversion and we read the ISR reg
-    uint8_t control = MARK_NONE;
+    TSample sample = {DC_OFFSET, MARK_NONE};
-    uint16_t sample = DC_OFFSET;
 
-    m_txBuffer.get(sample, control);
+    m_txBuffer.get(sample);
-    DACC->DACC_CDR = sample;
+    DACC->DACC_CDR = sample.sample;
 
-    sample = ADC->ADC_CDR[ADC_CDR_Chan];
+    sample.sample = ADC->ADC_CDR[ADC_CDR_Chan];
-    m_rxBuffer.put(sample, control);
+    m_rxBuffer.put(sample);
 
 #if defined(SEND_RSSI_DATA)
     m_rssiBuffer.put(ADC->ADC_CDR[RSSI_CDR_Chan]);

IOSTM.cpp

@@ -342,25 +342,24 @@ void CIO::startInt()
 
 void CIO::interrupt()
 {
-   uint8_t control  = MARK_NONE;
+   TSample sample = {DC_OFFSET, MARK_NONE};
-   uint16_t sample  = DC_OFFSET;
    uint16_t rawRSSI = 0U;
 
-   m_txBuffer.get(sample, control);
+   m_txBuffer.get(sample);
 
    // Send the value to the DAC
 #if defined(STM32F4_NUCLEO) && defined(STM32F4_NUCLEO_ARDUINO_HEADER)
-   DAC_SetChannel2Data(DAC_Align_12b_R, sample);
+   DAC_SetChannel2Data(DAC_Align_12b_R, sample.sample);
 #else
-   DAC_SetChannel1Data(DAC_Align_12b_R, sample);
+   DAC_SetChannel1Data(DAC_Align_12b_R, sample.sample);
 #endif
 
    // Read value from ADC1 and ADC2
    if ((ADC_GetFlagStatus(ADC1, ADC_FLAG_EOC) == RESET)) {
       // shouldn't be still in reset at this point so null the sample value?
-      sample  = 0U;
+      sample.sample  = 0U;
    } else {
-      sample  = ADC_GetConversionValue(ADC1);
+      sample.sample  = ADC_GetConversionValue(ADC1);
 #if defined(SEND_RSSI_DATA)
       rawRSSI = ADC_GetConversionValue(ADC2);
 #endif
@@ -370,7 +369,7 @@ void CIO::interrupt()
    ADC_ClearFlag(ADC1, ADC_FLAG_EOC);
    ADC_SoftwareStartConv(ADC1);
 
-   m_rxBuffer.put(sample, control);
+   m_rxBuffer.put(sample);
    m_rssiBuffer.put(rawRSSI);
 
    m_watchdog++;

IOSTM_CMSIS.cpp

@@ -370,8 +370,7 @@ void CIO::startInt()
 
 void CIO::interrupt()
 {
-  uint8_t control  = MARK_NONE;
+  TSample sample = {DC_OFFSET, MARK_NONE};
-  uint16_t sample  = DC_OFFSET;
 #if defined(SEND_RSSI_DATA)
   uint16_t rawRSSI = 0U;
 #endif
@@ -388,12 +387,12 @@ void CIO::interrupt()
     *rssi_adon = 1;
 #endif
     
-    m_txBuffer.get(sample, control);
+    m_txBuffer.get(sample);
-    DAC->DHR12R1 = sample;  // Send the value to the DAC
+    DAC->DHR12R1 = sample.sample;  // Send the value to the DAC
 
     // Read value from ADC1 and ADC2
-    sample  = ADC1->DR;   // read conversion result; EOC is cleared by this read
+    sample.sample  = ADC1->DR;   // read conversion result; EOC is cleared by this read
-    m_rxBuffer.put(sample, control);
+    m_rxBuffer.put(sample);
 #if defined(SEND_RSSI_DATA)
     rawRSSI = ADC2->DR;
     m_rssiBuffer.put(rawRSSI);

IOTeensy.cpp

@@ -164,15 +164,14 @@ void CIO::startInt()
 
 void CIO::interrupt()
 {
-  uint8_t control = MARK_NONE;
+   TSample sample = {DC_OFFSET, MARK_NONE};
-  uint16_t sample = DC_OFFSET;
 
-  m_txBuffer.get(sample, control);
+  m_txBuffer.get(sample);
-  *(int16_t *)&(DAC0_DAT0L) = sample;
+  *(int16_t *)&(DAC0_DAT0L) = sample.sample;
 
   if ((ADC0_SC1A & ADC_SC1_COCO) == ADC_SC1_COCO) {
-    sample = ADC0_RA;
+    sample.sample = ADC0_RA;
-    m_rxBuffer.put(sample, control);
+    m_rxBuffer.put(sample);
   }
     
 #if defined(SEND_RSSI_DATA)

M17TX.cpp

@@ -67,7 +67,8 @@ void CM17TX::process()
         m_poBuffer[m_poLen++] = M17_START_SYNC;
     } else {
       for (uint8_t i = 0U; i < M17_FRAME_LENGTH_BYTES; i++) {
-        uint8_t c = m_buffer.get();
+        uint8_t c = 0U;
+        m_buffer.get(c);
         m_poBuffer[m_poLen++] = c;
       }
     }

M17TX.h

@@ -21,7 +21,7 @@
 
 #include "Config.h"
 
-#include "SerialRB.h"
+#include "RingBuffer.h"
 
 class CM17TX {
 public:
@@ -38,7 +38,7 @@ public:
   void setParams(uint8_t txHang);
 
 private:
-  CSerialRB                        m_buffer;
+  CRingBuffer<uint8_t>             m_buffer;
   arm_fir_interpolate_instance_q15 m_modFilter;
   q15_t                            m_modState[16U];    // blockSize + phaseLength - 1, 4 + 9 - 1 plus some spare
   uint8_t                          m_poBuffer[1200U];

MMDVM.cpp

@@ -34,6 +34,7 @@ bool m_nxdnEnable   = true;
 bool m_m17Enable    = true;
 bool m_pocsagEnable = true;
 bool m_fmEnable     = true;
+bool m_ax25Enable   = true;
 
 bool m_duplex = true;
 
@@ -65,6 +66,8 @@ CM17TX     m17TX;
 CPOCSAGTX  pocsagTX;
 
 CFM        fm;
+CAX25RX    ax25RX;
+CAX25TX    ax25TX;
 
 CCalDStarRX calDStarRX;
 CCalDStarTX calDStarTX;
@@ -117,6 +120,9 @@ void loop()
   if (m_pocsagEnable && (m_modemState == STATE_POCSAG || pocsagTX.busy()))
     pocsagTX.process();
 
+  if (m_ax25Enable && (m_modemState == STATE_IDLE || m_modemState == STATE_FM))
+    ax25TX.process();
+
   if (m_fmEnable && m_modemState == STATE_FM)
     fm.process();
 

MMDVM.ino

@@ -31,6 +31,7 @@ bool m_nxdnEnable   = true;
 bool m_m17Enable    = true;
 bool m_pocsagEnable = true;
 bool m_fmEnable     = true;
+bool m_ax25Enable   = true;
 
 bool m_duplex = true;
 
@@ -62,6 +63,8 @@ CM17TX     m17TX;
 CPOCSAGTX  pocsagTX;
 
 CFM        fm;
+CAX25RX    ax25RX;
+CAX25TX    ax25TX;
 
 CCalDStarRX calDStarRX;
 CCalDStarTX calDStarTX;
@@ -114,6 +117,9 @@ void loop()
   if (m_pocsagEnable && (m_modemState == STATE_POCSAG || pocsagTX.busy()))
     pocsagTX.process();
 
+  if (m_ax25Enable && (m_modemState == STATE_IDLE || m_modemState == STATE_FM))
+    ax25TX.process();
+
   if (m_fmEnable && m_modemState == STATE_FM)
     fm.process();
 

Makefile.Arduino

@@ -1,5 +1,5 @@
 #!/usr/bin/make
-# makefile for the arduino due (works with arduino IDE 1.6.11)
+# makefile for the arduino due (works with arduino IDE 1.6.12)
 #
 # The original file can be found at https://github.com/pauldreik/arduino-due-makefile
 #
@@ -34,7 +34,7 @@ OBJCOPY:=$(ADIR)/packages/arduino/tools/arm-none-eabi-gcc/4.8.3-2014q1/bin/arm-n
 
 C:=$(CC)
 #SAM:=arduino/sam/
-SAM:=$(ADIR)/packages/arduino/hardware/sam/1.6.11
+SAM:=$(ADIR)/packages/arduino/hardware/sam/1.6.12
 #CMSIS:=arduino/sam/system/CMSIS/
 #LIBSAM:=arduino/sam/system/libsam
 TMPDIR:=$(PWD)/build

NXDNTX.cpp

@@ -81,7 +81,8 @@ void CNXDNTX::process()
       m_poBuffer[m_poLen++] = NXDN_PREAMBLE[2U];
     } else {
       for (uint8_t i = 0U; i < NXDN_FRAME_LENGTH_BYTES; i++) {
-        uint8_t c = m_buffer.get();
+        uint8_t c = 0U;
+        m_buffer.get(c);
         m_poBuffer[m_poLen++] = c;
       }
     }
@@ -122,7 +123,7 @@ void CNXDNTX::process()
   }
 }
 
-uint8_t CNXDNTX::writeData(const uint8_t* data, uint8_t length)
+uint8_t CNXDNTX::writeData(const uint8_t* data, uint16_t length)
 {
   if (length != (NXDN_FRAME_LENGTH_BYTES + 1U))
     return 4U;

NXDNTX.h

@@ -21,13 +21,13 @@
 
 #include "Config.h"
 
-#include "SerialRB.h"
+#include "RingBuffer.h"
 
 class CNXDNTX {
 public:
   CNXDNTX();
 
-  uint8_t writeData(const uint8_t* data, uint8_t length);
+  uint8_t writeData(const uint8_t* data, uint16_t length);
 
   void process();
 
@@ -38,7 +38,7 @@ public:
   void setParams(uint8_t txHang);
 
 private:
-  CSerialRB                        m_buffer;
+  CRingBuffer<uint8_t>                        m_buffer;
   arm_fir_interpolate_instance_q15 m_modFilter;
   arm_fir_instance_q15             m_sincFilter;
   q15_t                            m_modState[16U];    // blockSize + phaseLength - 1, 4 + 9 - 1 plus some spare

P25TX.cpp

@@ -75,9 +75,11 @@ void CP25TX::process()
       for (uint16_t i = 0U; i < m_txDelay; i++)
         m_poBuffer[m_poLen++] = P25_START_SYNC;
     } else {
-      uint8_t length = m_buffer.get();
+      uint8_t length;
+      m_buffer.get(length);
       for (uint8_t i = 0U; i < length; i++) {
-        uint8_t c = m_buffer.get();
+        uint8_t c = 0U;
+        m_buffer.get(c);
         m_poBuffer[m_poLen++] = c;
       }
     }
@@ -118,7 +120,7 @@ void CP25TX::process()
   }
 }
 
-uint8_t CP25TX::writeData(const uint8_t* data, uint8_t length)
+uint8_t CP25TX::writeData(const uint8_t* data, uint16_t length)
 {
   if (length < (P25_TERM_FRAME_LENGTH_BYTES + 1U))
     return 4U;

P25TX.h

@@ -21,13 +21,13 @@
 
 #include "Config.h"
 
-#include "SerialRB.h"
+#include "RingBuffer.h"
 
 class CP25TX {
 public:
   CP25TX();
 
-  uint8_t writeData(const uint8_t* data, uint8_t length);
+  uint8_t writeData(const uint8_t* data, uint16_t length);
 
   void process();
 
@@ -38,7 +38,7 @@ public:
   void setParams(uint8_t txHang);
 
 private:
-  CSerialRB                        m_buffer;
+  CRingBuffer<uint8_t>                        m_buffer;
   arm_fir_interpolate_instance_q15 m_modFilter;
   arm_fir_instance_q15             m_lpFilter;
   q15_t                            m_modState[16U];    // blockSize + phaseLength - 1, 4 + 9 - 1 plus some spare

POCSAGTX.cpp

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2018 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2018,2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -61,7 +61,8 @@ void CPOCSAGTX::process()
         m_poBuffer[m_poLen++] = POCSAG_SYNC;
     } else {
       for (uint8_t i = 0U; i < POCSAG_FRAME_LENGTH_BYTES; i++) {
-        uint8_t c = m_buffer.get();
+        uint8_t c = 0U;
+        m_buffer.get(c);
         m_poBuffer[m_poLen++] = c;
       }
     }
@@ -95,7 +96,7 @@ bool CPOCSAGTX::busy()
     return false;
 }
 
-uint8_t CPOCSAGTX::writeData(const uint8_t* data, uint8_t length)
+uint8_t CPOCSAGTX::writeData(const uint8_t* data, uint16_t length)
 {
   if (length != POCSAG_FRAME_LENGTH_BYTES)
     return 4U;
@@ -146,4 +147,3 @@ uint8_t CPOCSAGTX::getSpace() const
 {
   return m_buffer.getSpace() / POCSAG_FRAME_LENGTH_BYTES;
 }
-

POCSAGTX.h

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2015-2019 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2015-2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -21,13 +21,13 @@
 
 #include "Config.h"
 
-#include "SerialRB.h"
+#include "RingBuffer.h"
 
 class CPOCSAGTX {
 public:
   CPOCSAGTX();
 
-  uint8_t writeData(const uint8_t* data, uint8_t length);
+  uint8_t writeData(const uint8_t* data, uint16_t length);
 
   void writeByte(uint8_t c);
 
@@ -40,7 +40,7 @@ public:
   bool busy();
 
 private:
-  CSerialRB            m_buffer;
+  CRingBuffer<uint8_t>            m_buffer;
   arm_fir_instance_q15 m_modFilter;
   q15_t                m_modState[170U];     // NoTaps + BlockSize - 1, 6 + 160 - 1 plus some spare
   uint8_t              m_poBuffer[200U];

RSSIRB.cpp

@@ -1,102 +0,0 @@
-/*
-TX fifo control - Copyright (C) KI6ZUM 2015
-Copyright (C) 2015,2016 by Jonathan Naylor G4KLX
-
-This library is free software; you can redistribute it and/or
-modify it under the terms of the GNU Library General Public
-License as published by the Free Software Foundation; either
-version 2 of the License, or (at your option) any later version.
-
-This library is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-Library General Public License for more details.
-
-You should have received a copy of the GNU Library General Public
-License along with this library; if not, write to the
-Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
-Boston, MA  02110-1301, USA.
-*/
-
-#include "RSSIRB.h"
-
-CRSSIRB::CRSSIRB(uint16_t length) :
-m_length(length),
-m_head(0U),
-m_tail(0U),
-m_full(false),
-m_overflow(false)
-{
-  m_rssi = new uint16_t[length];
-}
-
-uint16_t CRSSIRB::getSpace() const
-{
-  uint16_t n = 0U;
-
-  if (m_tail == m_head)
-    n = m_full ? 0U : m_length;
-  else if (m_tail < m_head)
-    n = m_length - m_head + m_tail;
-  else
-    n = m_tail - m_head;
-
-  if (n > m_length)
-    n = 0U;
-
-  return n;
-}
-
-uint16_t CRSSIRB::getData() const
-{
-  if (m_tail == m_head)
-    return m_full ? m_length : 0U;
-  else if (m_tail < m_head)
-    return m_head - m_tail;
-  else
-    return m_length - m_tail + m_head;
-}
-
-bool CRSSIRB::put(uint16_t rssi)
-{
-  if (m_full) {
-    m_overflow = true;
-    return false;
-  }
-
-  m_rssi[m_head] = rssi;
-
-  m_head++;
-  if (m_head >= m_length)
-    m_head = 0U;
-
-  if (m_head == m_tail)
-    m_full = true;
-
-  return true;
-}
-
-bool CRSSIRB::get(uint16_t& rssi)
-{
-  if (m_head == m_tail && !m_full)
-    return false;
-
-  rssi  = m_rssi[m_tail];
-
-  m_full = false;
-
-  m_tail++;
-  if (m_tail >= m_length)
-    m_tail = 0U;
-
-  return true;
-}
-
-bool CRSSIRB::hasOverflowed()
-{
-  bool overflow = m_overflow;
-
-  m_overflow = false;
-
-  return overflow;
-}

RSSIRB.h

@@ -1,59 +0,0 @@
-/*
-Serial fifo control - Copyright (C) KI6ZUM 2015
-Copyright (C) 2015,2016 by Jonathan Naylor G4KLX
-
-This library is free software; you can redistribute it and/or
-modify it under the terms of the GNU Library General Public
-License as published by the Free Software Foundation; either
-version 2 of the License, or (at your option) any later version.
-
-This library is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-Library General Public License for more details.
-
-You should have received a copy of the GNU Library General Public
-License along with this library; if not, write to the
-Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
-Boston, MA  02110-1301, USA.
-*/
-
-#if !defined(RSSIRB_H)
-#define  RSSIRB_H
-
-#if defined(STM32F4XX)
-#include "stm32f4xx.h"
-#elif defined(STM32F7XX)
-#include "stm32f7xx.h"
-#elif defined(STM32F105xC)
-#include "stm32f1xx.h"
-#include <cstddef>
-#else
-#include <Arduino.h>
-#endif
-
-class CRSSIRB {
-public:
-  CRSSIRB(uint16_t length);
-  
-  uint16_t getSpace() const;
-  
-  uint16_t getData() const;
-
-  bool put(uint16_t rssi);
-
-  bool get(uint16_t& rssi);
-
-  bool hasOverflowed();
-
-private:
-  uint16_t           m_length;
-  volatile uint16_t* m_rssi;
-  volatile uint16_t  m_head;
-  volatile uint16_t  m_tail;
-  volatile bool      m_full;
-  bool               m_overflow;
-};
-
-#endif
-

RingBuffer.h

@@ -1,5 +1,6 @@
 /*
  *   Copyright (C) 2020 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2020 by Geoffrey Merck F4FXL - KC3FRA
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -16,8 +17,8 @@
  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
-#if !defined(FMDOWNSAMPLERB_H)
+#if !defined(RINGBUFFER_H)
-#define  FMDOWNSAMPLERB_H
+#define  RINGBUFFER_H
 
 #if defined(STM32F4XX)
 #include "stm32f4xx.h"
@@ -28,6 +29,7 @@
 #include <cstddef>
 #else
 #include <Arduino.h>
+#undef PI
 #endif
 
 #if defined(__SAM3X8E__) || defined(STM32F105xC)
@@ -42,27 +44,34 @@
 
 #include <arm_math.h>
 
-class CFMDownsampleRB {
+template <typename TDATATYPE>
+class CRingBuffer {
 public:
-  CFMDownsampleRB(uint16_t length);
+  CRingBuffer(uint16_t length = 370U);
   
   uint16_t getSpace() const;
   
   uint16_t getData() const;
 
-  bool put(uint8_t sample);
+  bool put(TDATATYPE item) volatile;
 
-  bool get(uint8_t& sample);
+  bool get(TDATATYPE& item) volatile;
+
+  TDATATYPE peek() const;
 
   bool hasOverflowed();
 
+  void reset();
+
 private:
   uint16_t              m_length;
-  volatile uint8_t* m_samples;
+  TDATATYPE*            m_buffer;
   volatile uint16_t     m_head;
   volatile uint16_t     m_tail;
   volatile bool         m_full;
   bool                  m_overflow;
 };
 
+#include "RingBuffer.impl.h"
+
 #endif

RingBuffer.impl.h

@@ -1,5 +1,6 @@
 /*
  *   Copyright (C) 2020 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2020 by Geoffrey Merck F4FXL - KC3FRA
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -16,20 +17,19 @@
  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
+#include "RingBuffer.h"
 
-#include "FMDownsampleRB.h"
+template <typename TDATATYPE> CRingBuffer<TDATATYPE>::CRingBuffer(uint16_t length) :
-
-CFMDownsampleRB::CFMDownsampleRB(uint16_t length) :
 m_length(length),
 m_head(0U),
 m_tail(0U),
 m_full(false),
 m_overflow(false)
 {
-  m_samples = new uint8_t[length];
+  m_buffer = new TDATATYPE[length];
 }
 
-uint16_t CFMDownsampleRB::getSpace() const
+template <typename TDATATYPE> uint16_t CRingBuffer<TDATATYPE>::getSpace() const
 {
   uint16_t n = 0U;
 
@@ -46,7 +46,7 @@ uint16_t CFMDownsampleRB::getSpace() const
   return n;
 }
 
-uint16_t CFMDownsampleRB::getData() const
+template <typename TDATATYPE> uint16_t CRingBuffer<TDATATYPE>::getData() const
 {
   if (m_tail == m_head)
     return m_full ? m_length : 0U;
@@ -56,14 +56,14 @@ uint16_t CFMDownsampleRB::getData() const
     return m_length - m_tail + m_head;
 }
 
-bool CFMDownsampleRB::put(uint8_t sample)
+template <typename TDATATYPE> bool CRingBuffer<TDATATYPE>::put(TDATATYPE item) volatile
 {
   if (m_full) {
     m_overflow = true;
     return false;
   }
 
-  m_samples[m_head] = sample;
+  m_buffer[m_head] = item;
 
   m_head++;
   if (m_head >= m_length)
@@ -75,12 +75,17 @@ bool CFMDownsampleRB::put(uint8_t sample)
   return true;
 }
 
-bool CFMDownsampleRB::get(uint8_t& sample)
+template <typename TDATATYPE> TDATATYPE CRingBuffer<TDATATYPE>::peek() const
+{
+  return m_buffer[m_tail];
+}
+
+template <typename TDATATYPE> bool CRingBuffer<TDATATYPE>::get(TDATATYPE& item) volatile
 {
   if (m_head == m_tail && !m_full)
     return false;
 
-  sample = m_samples[m_tail];
+  item = m_buffer[m_tail];
 
   m_full = false;
 
@@ -91,7 +96,7 @@ bool CFMDownsampleRB::get(uint8_t& sample)
   return true;
 }
 
-bool CFMDownsampleRB::hasOverflowed()
+template <typename TDATATYPE> bool CRingBuffer<TDATATYPE>::hasOverflowed()
 {
   bool overflow = m_overflow;
 
@@ -99,3 +104,11 @@ bool CFMDownsampleRB::hasOverflowed()
 
   return overflow;
 }
+
+template <typename TDATATYPE> void CRingBuffer<TDATATYPE>::reset()
+{
+  m_head = 0U;
+  m_tail = 0U;
+  m_full     = false;
+  m_overflow = false;
+}

STMUART.cpp

@@ -0,0 +1,100 @@
+/*
+ *   Copyright (c) 2020 by Jonathan Naylor G4KLX
+ *   Copyright (c) 2020 by Geoffrey Merck F4FXL - KC3FRA   
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#if defined(STM32F4XX) || defined(STM32F7XX)
+
+#include "STMUART.h"
+
+CSTMUART::CSTMUART() :
+m_usart(NULL)
+{
+
+}
+
+void CSTMUART::init(USART_TypeDef* usart)
+{
+  m_usart = usart;
+}
+
+void CSTMUART::write(const uint8_t * data, uint16_t length)
+{
+  if(length == 0U || m_usart == NULL)
+    return;
+
+
+  m_txFifo.put(data[0]);
+  USART_ITConfig(m_usart, USART_IT_TXE, ENABLE);//switch TX IRQ is on
+
+  for(uint16_t i = 1U; i < length; i++) {
+    m_txFifo.put(data[i]);
+  }
+
+  USART_ITConfig(m_usart, USART_IT_TXE, ENABLE);//make sure TX IRQ is on
+}
+
+uint8_t CSTMUART::read()
+{
+  return m_rxFifo.get();
+}
+
+void CSTMUART::handleIRQ()
+{
+  if(m_usart == NULL)
+    return;
+
+  if (USART_GetITStatus(m_usart, USART_IT_RXNE)) {
+    if(!m_rxFifo.isFull())
+      m_rxFifo.put((uint8_t) USART_ReceiveData(m_usart));
+    USART_ClearITPendingBit(USART1, USART_IT_RXNE);
+  }
+
+  if (USART_GetITStatus(m_usart, USART_IT_TXE)) {
+    if(!m_txFifo.isEmpty())
+      USART_SendData(m_usart, m_txFifo.get());
+
+    USART_ClearITPendingBit(m_usart, USART_IT_TXE);
+
+    if (m_txFifo.isEmpty()) // if there's no more data to transmit then turn off TX interrupts
+      USART_ITConfig(m_usart, USART_IT_TXE, DISABLE);
+  }
+}
+
+  // Flushes the transmit shift register
+// warning: this call is blocking
+void CSTMUART::flush()
+{
+  if(m_usart == NULL)
+    return;
+
+   // wait until the TXE shows the shift register is empty
+   while (USART_GetITStatus(m_usart, USART_FLAG_TXE))
+      ;
+}
+
+uint16_t CSTMUART::available()
+{
+  return m_rxFifo.isEmpty() ? 0U : 1U;
+}
+
+uint16_t CSTMUART::availableForWrite()
+{
+  return m_txFifo.isFull() ? 0U : 1U;
+}
+
+#endif

STMUART.h

@@ -0,0 +1,91 @@
+/*
+ *   Copyright (c) 2020 by Jonathan Naylor G4KLX
+ *   Copyright (c) 2020 by Geoffrey Merck F4FXL - KC3FRA   
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#if defined(STM32F4XX) || defined(STM32F7XX)
+#if !defined(STMUART_H)
+#define STMUART_H
+
+#if defined(STM32F4XX)
+#include "stm32f4xx.h"
+#elif defined(STM32F7XX)
+#include "stm32f7xx.h"
+#endif
+
+const uint16_t BUFFER_SIZE = 2048U; //needs to be a power of 2 !
+const uint16_t BUFFER_MASK = BUFFER_SIZE - 1;
+
+class CSTMUARTFIFO {
+public:
+  CSTMUARTFIFO() :
+  m_head(0U),
+  m_tail(0U)
+  {
+  }
+
+  void put(uint8_t data)
+  {
+    m_buffer[BUFFER_MASK & (m_head++)] = data;
+  }
+
+  uint8_t get()
+  {
+    return m_buffer[BUFFER_MASK & (m_tail++)];
+  }
+
+  void reset()
+  {
+    m_tail = 0U;
+    m_head = 0U;
+  }
+
+  bool isEmpty()
+  {
+    return m_tail == m_head;
+  }
+
+  bool isFull()
+  {
+    return ((m_head + 1U) & BUFFER_MASK) == (m_tail & BUFFER_MASK);
+  }
+
+private:
+  volatile uint8_t  m_buffer[BUFFER_SIZE];
+  volatile uint16_t m_head;
+  volatile uint16_t m_tail;
+};
+
+class CSTMUART {
+public:
+  CSTMUART();
+  void init(USART_TypeDef* usart);
+  void write(const uint8_t * data, uint16_t length);
+  uint8_t read();
+  void handleIRQ();
+  void flush();
+  uint16_t available();
+  uint16_t availableForWrite();
+
+private:
+  USART_TypeDef * m_usart;
+  CSTMUARTFIFO    m_rxFifo;
+  CSTMUARTFIFO    m_txFifo;
+};
+
+#endif
+#endif

SampleRB.cpp

@@ -1,106 +0,0 @@
-/*
-TX fifo control - Copyright (C) KI6ZUM 2015
-Copyright (C) 2015,2016 by Jonathan Naylor G4KLX
-
-This library is free software; you can redistribute it and/or
-modify it under the terms of the GNU Library General Public
-License as published by the Free Software Foundation; either
-version 2 of the License, or (at your option) any later version.
-
-This library is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-Library General Public License for more details.
-
-You should have received a copy of the GNU Library General Public
-License along with this library; if not, write to the
-Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
-Boston, MA  02110-1301, USA.
-*/
-
-#include "SampleRB.h"
-
-CSampleRB::CSampleRB(uint16_t length) :
-m_length(length),
-m_head(0U),
-m_tail(0U),
-m_full(false),
-m_overflow(false)
-{
-  m_samples = new uint16_t[length];
-  m_control = new uint8_t[length];
-}
-
-uint16_t CSampleRB::getSpace() const
-{
-  uint16_t n = 0U;
-
-  if (m_tail == m_head)
-    n = m_full ? 0U : m_length;
-  else if (m_tail < m_head)
-    n = m_length - m_head + m_tail;
-  else
-    n = m_tail - m_head;
-
-  if (n > m_length)
-    n = 0U;
-
-  return n;
-}
-
-uint16_t CSampleRB::getData() const
-{
-  if (m_tail == m_head)
-    return m_full ? m_length : 0U;
-  else if (m_tail < m_head)
-    return m_head - m_tail;
-  else
-    return m_length - m_tail + m_head;
-}
-
-bool CSampleRB::put(uint16_t sample, uint8_t control)
-{
-  if (m_full) {
-    m_overflow = true;
-    return false;
-  }
-
-  m_samples[m_head] = sample;
-  m_control[m_head] = control;
-
-  m_head++;
-  if (m_head >= m_length)
-    m_head = 0U;
-
-  if (m_head == m_tail)
-    m_full = true;
-
-  return true;
-}
-
-bool CSampleRB::get(uint16_t& sample, uint8_t& control)
-{
-  if (m_head == m_tail && !m_full)
-    return false;
-
-  sample  = m_samples[m_tail];
-  control = m_control[m_tail];
-
-  m_full = false;
-
-  m_tail++;
-  if (m_tail >= m_length)
-    m_tail = 0U;
-
-  return true;
-}
-
-bool CSampleRB::hasOverflowed()
-{
-  bool overflow = m_overflow;
-
-  m_overflow = false;
-
-  return overflow;
-}
-

SampleRB.h

@@ -1,60 +0,0 @@
-/*
-Serial fifo control - Copyright (C) KI6ZUM 2015
-Copyright (C) 2015,2016 by Jonathan Naylor G4KLX
-
-This library is free software; you can redistribute it and/or
-modify it under the terms of the GNU Library General Public
-License as published by the Free Software Foundation; either
-version 2 of the License, or (at your option) any later version.
-
-This library is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-Library General Public License for more details.
-
-You should have received a copy of the GNU Library General Public
-License along with this library; if not, write to the
-Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
-Boston, MA  02110-1301, USA.
-*/
-
-#if !defined(SAMPLERB_H)
-#define  SAMPLERB_H
-
-#if defined(STM32F4XX)
-#include "stm32f4xx.h"
-#elif defined(STM32F7XX)
-#include "stm32f7xx.h"
-#elif defined(STM32F105xC)
-#include "stm32f1xx.h"
-#include <cstddef>
-#else
-#include <Arduino.h>
-#endif
-
-class CSampleRB {
-public:
-  CSampleRB(uint16_t length);
-  
-  uint16_t getSpace() const;
-  
-  uint16_t getData() const;
-
-  bool put(uint16_t sample, uint8_t control);
-
-  bool get(uint16_t& sample, uint8_t& control);
-
-  bool hasOverflowed();
-
-private:
-  uint16_t           m_length;
-  volatile uint16_t* m_samples;
-  volatile uint8_t*  m_control;
-  volatile uint16_t  m_head;
-  volatile uint16_t  m_tail;
-  volatile bool      m_full;
-  bool               m_overflow;
-};
-
-#endif
-

SerialPort.cpp

@@ -68,9 +68,15 @@ const uint8_t MMDVM_M17_LOST     = 0x46U;
 
 const uint8_t MMDVM_POCSAG_DATA  = 0x50U;
 
+const uint8_t MMDVM_AX25_DATA    = 0x55U;
+
 const uint8_t MMDVM_FM_PARAMS1   = 0x60U;
 const uint8_t MMDVM_FM_PARAMS2   = 0x61U;
 const uint8_t MMDVM_FM_PARAMS3   = 0x62U;
+const uint8_t MMDVM_FM_PARAMS4   = 0x63U;
+const uint8_t MMDVM_FM_DATA      = 0x65U;
+const uint8_t MMDVM_FM_STATUS    = 0x66U;
+const uint8_t MMDVM_FM_EOT       = 0x67U;
 
 const uint8_t MMDVM_ACK          = 0x70U;
 const uint8_t MMDVM_NAK          = 0x7FU;
@@ -106,7 +112,7 @@ const uint8_t MMDVM_DEBUG5       = 0xF5U;
 #define	HW_TYPE	"MMDVM"
 #endif
 
-#define DESCRIPTION "20201015 (D-Star/DMR/System Fusion/P25/NXDN/M17/POCSAG/FM)"
+#define DESCRIPTION "20201106 (D-Star/DMR/System Fusion/P25/NXDN/M17/POCSAG/FM/AX.25)"
 
 #if defined(GITVERSION)
 #define concat(h, a, b, c) h " " a " " b " GitID #" c ""
@@ -161,82 +167,69 @@ void CSerialPort::getStatus()
 
   // Send all sorts of interesting internal values
   reply[0U]  = MMDVM_FRAME_START;
-  reply[1U]  = 14U;
+  reply[1U]  = 15U;
   reply[2U]  = MMDVM_GET_STATUS;
 
-  reply[3U]  = 0x00U;
+  reply[3U]  = uint8_t(m_modemState);
-  if (m_dstarEnable)
-    reply[3U] |= 0x01U;
-  if (m_dmrEnable)
-    reply[3U] |= 0x02U;
-  if (m_ysfEnable)
-    reply[3U] |= 0x04U;
-  if (m_p25Enable)
-    reply[3U] |= 0x08U;
-  if (m_nxdnEnable)
-    reply[3U] |= 0x10U;
-  if (m_pocsagEnable)
-    reply[3U] |= 0x20U;
-  if (m_fmEnable)
-    reply[3U] |= 0x40U;
-  if (m_m17Enable)
-    reply[3U] |= 0x80U;
 
-  reply[4U]  = uint8_t(m_modemState);
+  reply[4U]  = m_tx  ? 0x01U : 0x00U;
-
-  reply[5U]  = m_tx  ? 0x01U : 0x00U;
 
   bool adcOverflow;
   bool dacOverflow;
   io.getOverflow(adcOverflow, dacOverflow);
 
   if (adcOverflow)
-    reply[5U] |= 0x02U;
+    reply[4U] |= 0x02U;
 
   if (io.hasRXOverflow())
-    reply[5U] |= 0x04U;
+    reply[4U] |= 0x04U;
 
   if (io.hasTXOverflow())
-    reply[5U] |= 0x08U;
+    reply[4U] |= 0x08U;
 
   if (io.hasLockout())
-    reply[5U] |= 0x10U;
+    reply[4U] |= 0x10U;
 
   if (dacOverflow)
-    reply[5U] |= 0x20U;
+    reply[4U] |= 0x20U;
     
-  reply[5U] |= m_dcd ? 0x40U : 0x00U;
+  reply[4U] |= m_dcd ? 0x40U : 0x00U;
 
   if (m_dstarEnable)
-    reply[6U] = dstarTX.getSpace();
+    reply[5U] = dstarTX.getSpace();
   else
-    reply[6U] = 0U;
+    reply[5U] = 0U;
 
   if (m_dmrEnable) {
     if (m_duplex) {
-      reply[7U] = dmrTX.getSpace1();
+      reply[6U] = dmrTX.getSpace1();
-      reply[8U] = dmrTX.getSpace2();
+      reply[7U] = dmrTX.getSpace2();
     } else {
-      reply[7U] = 10U;
+      reply[6U] = 10U;
-      reply[8U] = dmrDMOTX.getSpace();
+      reply[7U] = dmrDMOTX.getSpace();
     }
   } else {
+    reply[6U] = 0U;
     reply[7U] = 0U;
-    reply[8U] = 0U;
   }
 
   if (m_ysfEnable)
-    reply[9U] = ysfTX.getSpace();
+    reply[8U] = ysfTX.getSpace();
+  else
+    reply[8U] = 0U;
+
+  if (m_p25Enable)
+    reply[9U] = p25TX.getSpace();
   else
     reply[9U] = 0U;
 
-  if (m_p25Enable)
+  if (m_nxdnEnable)
-    reply[10U] = p25TX.getSpace();
+    reply[10U] = nxdnTX.getSpace();
   else
     reply[10U] = 0U;
 
-  if (m_nxdnEnable)
+  if (m_m17Enable)
-    reply[11U] = nxdnTX.getSpace();
+    reply[11U] = m17TX.getSpace();
   else
     reply[11U] = 0U;
 
@@ -245,12 +238,17 @@ void CSerialPort::getStatus()
   else
     reply[12U] = 0U;
 
-  if (m_m17Enable)
+  if (m_fmEnable)
-    reply[13U] = m17TX.getSpace();
+    reply[13U] = fm.getSpace();
   else
     reply[13U] = 0U;
 
-  writeInt(1U, reply, 14);
+  if (m_ax25Enable)
+    reply[14U] = ax25TX.getSpace();
+  else
+    reply[14U] = 0U;
+
+  writeInt(1U, reply, 15);
 }
 
 void CSerialPort::getVersion()
@@ -272,9 +270,9 @@ void CSerialPort::getVersion()
   writeInt(1U, reply, count);
 }
 
-uint8_t CSerialPort::setConfig(const uint8_t* data, uint8_t length)
+uint8_t CSerialPort::setConfig(const uint8_t* data, uint16_t length)
 {
-  if (length < 23U)
+  if (length < 28U)
     return 4U;
 
   bool rxInvert        = (data[0U] & 0x01U) == 0x01U;
@@ -291,15 +289,17 @@ uint8_t CSerialPort::setConfig(const uint8_t* data, uint8_t length)
   bool ysfEnable    = (data[1U] & 0x04U) == 0x04U;
   bool p25Enable    = (data[1U] & 0x08U) == 0x08U;
   bool nxdnEnable   = (data[1U] & 0x10U) == 0x10U;
-  bool pocsagEnable = (data[1U] & 0x20U) == 0x20U;
+  bool fmEnable     = (data[1U] & 0x20U) == 0x20U;
-  bool fmEnable     = (data[1U] & 0x40U) == 0x40U;
+  bool m17Enable    = (data[1U] & 0x40U) == 0x40U;
-  bool m17Enable    = (data[1U] & 0x80U) == 0x80U;
 
-  uint8_t txDelay = data[2U];
+  bool pocsagEnable = (data[2U] & 0x01U) == 0x01U;
+  bool ax25Enable   = (data[2U] & 0x02U) == 0x02U;
+
+  uint8_t txDelay = data[3U];
   if (txDelay > 50U)
     return 4U;
 
-  MMDVM_STATE modemState = MMDVM_STATE(data[3U]);
+  MMDVM_STATE modemState = MMDVM_STATE(data[4U]);
 
   if (modemState != STATE_IDLE && modemState != STATE_DSTAR && modemState != STATE_DMR && modemState != STATE_YSF && modemState != STATE_P25 && modemState != STATE_NXDN && modemState != STATE_M17 && modemState != STATE_POCSAG && modemState != STATE_FM && modemState != STATE_DSTARCAL && modemState != STATE_DMRCAL && modemState != STATE_RSSICAL && modemState != STATE_LFCAL && modemState != STATE_DMRCAL1K && modemState != STATE_P25CAL1K && modemState != STATE_DMRDMO1K && modemState != STATE_NXDNCAL1K && modemState != STATE_POCSAGCAL && modemState != STATE_FMCAL10K && modemState != STATE_FMCAL12K && modemState != STATE_FMCAL15K && modemState != STATE_FMCAL20K && modemState != STATE_FMCAL25K && modemState != STATE_FMCAL30K)
     return 4U;
@@ -320,37 +320,40 @@ uint8_t CSerialPort::setConfig(const uint8_t* data, uint8_t length)
   if (modemState == STATE_FM && !fmEnable)
     return 4U;
 
-  uint8_t rxLevel = data[4U];
+  int16_t txDCOffset = int16_t(data[5U]) - 128;
+  int16_t rxDCOffset = int16_t(data[6U]) - 128;
 
-  uint8_t colorCode = data[6U];
+  uint8_t rxLevel = data[7U];
-  if (colorCode > 15U)
-    return 4U;
 
-  uint8_t dmrDelay = data[7U];
+  uint8_t cwIdTXLevel   = data[8U];
-
-  uint8_t cwIdTXLevel  = data[5U];
   uint8_t dstarTXLevel  = data[9U];
   uint8_t dmrTXLevel    = data[10U];
   uint8_t ysfTXLevel    = data[11U];
   uint8_t p25TXLevel    = data[12U];
+  uint8_t nxdnTXLevel   = data[13U];
+  uint8_t m17TXLevel    = data[14U];
+  uint8_t pocsagTXLevel = data[15U];
+  uint8_t fmTXLevel     = data[16U];
+  uint8_t ax25TXLevel   = data[17U];
 
-  int16_t txDCOffset = int16_t(data[13U]) - 128;
+  uint8_t ysfTXHang     = data[18U];
-  int16_t rxDCOffset = int16_t(data[14U]) - 128;
-
-  uint8_t nxdnTXLevel   = data[15U];
-
-  uint8_t ysfTXHang     = data[16U];
-
-  uint8_t pocsagTXLevel = data[17U];
-
-  uint8_t fmTXLevel     = data[18U];
-
   uint8_t p25TXHang     = data[19U];
-
   uint8_t nxdnTXHang    = data[20U];
+  uint8_t m17TXHang     = data[21U];
 
-  uint8_t m17TXLevel    = data[21U];
+  uint8_t colorCode = data[22U];
-  uint8_t m17TXHang     = data[22U];
+  if (colorCode > 15U)
+    return 4U;
+
+  uint8_t dmrDelay = data[23U];
+
+  int8_t ax25RXTwist    = int8_t(data[24U]) - 128;
+  if (ax25RXTwist < -4 || ax25RXTwist > 10)
+    return 4U;
+
+  uint8_t ax25TXDelay   = data[25U];
+  uint8_t ax25SlotTime  = data[26U];
+  uint8_t ax25PPersist  = data[27U];
 
   setMode(modemState);
 
@@ -362,6 +365,7 @@ uint8_t CSerialPort::setConfig(const uint8_t* data, uint8_t length)
   m_m17Enable    = m17Enable;
   m_pocsagEnable = pocsagEnable;
   m_fmEnable     = fmEnable;
+  m_ax25Enable   = ax25Enable;
   m_duplex       = !simplex;
 
   dstarTX.setTXDelay(txDelay);
@@ -371,6 +375,7 @@ uint8_t CSerialPort::setConfig(const uint8_t* data, uint8_t length)
   nxdnTX.setTXDelay(txDelay);
   m17TX.setTXDelay(txDelay);
   pocsagTX.setTXDelay(txDelay);
+  ax25TX.setTXDelay(ax25TXDelay);
 
   dmrTX.setColorCode(colorCode);
   dmrRX.setColorCode(colorCode);
@@ -382,15 +387,16 @@ uint8_t CSerialPort::setConfig(const uint8_t* data, uint8_t length)
   p25TX.setParams(p25TXHang);
   nxdnTX.setParams(nxdnTXHang);
   m17TX.setParams(m17TXHang);
+  ax25RX.setParams(ax25RXTwist, ax25SlotTime, ax25PPersist);
 
-  io.setParameters(rxInvert, txInvert, pttInvert, rxLevel, cwIdTXLevel, dstarTXLevel, dmrTXLevel, ysfTXLevel, p25TXLevel, nxdnTXLevel, m17TXLevel, pocsagTXLevel, fmTXLevel, txDCOffset, rxDCOffset, useCOSAsLockout);
+  io.setParameters(rxInvert, txInvert, pttInvert, rxLevel, cwIdTXLevel, dstarTXLevel, dmrTXLevel, ysfTXLevel, p25TXLevel, nxdnTXLevel, m17TXLevel, pocsagTXLevel, fmTXLevel, ax25TXLevel, txDCOffset, rxDCOffset, useCOSAsLockout);
 
   io.start();
 
   return 0U;
 }
 
-uint8_t CSerialPort::setFMParams1(const uint8_t* data, uint8_t length)
+uint8_t CSerialPort::setFMParams1(const uint8_t* data, uint16_t length)
 {
   if (length < 8U)
     return 4U;
@@ -415,7 +421,7 @@ uint8_t CSerialPort::setFMParams1(const uint8_t* data, uint8_t length)
   return fm.setCallsign(callsign, speed, frequency, time, holdoff, highLevel, lowLevel, callAtStart, callAtEnd, callAtLatch);
 }
 
-uint8_t CSerialPort::setFMParams2(const uint8_t* data, uint8_t length)
+uint8_t CSerialPort::setFMParams2(const uint8_t* data, uint16_t length)
 {
   if (length < 6U)
     return 4U;
@@ -435,9 +441,9 @@ uint8_t CSerialPort::setFMParams2(const uint8_t* data, uint8_t length)
   return fm.setAck(ack, speed, frequency, minTime, delay, level);
 }
 
-uint8_t CSerialPort::setFMParams3(const uint8_t* data, uint8_t length)
+uint8_t CSerialPort::setFMParams3(const uint8_t* data, uint16_t length)
 {
-  if (length < 12U)
+  if (length < 14U)
     return 4U;
 
   uint16_t timeout        = data[0U] * 5U;
@@ -451,17 +457,40 @@ uint8_t CSerialPort::setFMParams3(const uint8_t* data, uint8_t length)
   uint8_t  kerchunkTime   = data[6U];
   uint8_t  hangTime       = data[7U];
 
-  uint8_t  accessMode     = data[8U] & 0x7FU;
+  uint8_t  accessMode     = data[8U] & 0x0FU;
+  bool     noiseSquelch   = (data[8U] & 0x40U) == 0x40U;
   bool     cosInvert      = (data[8U] & 0x80U) == 0x80U;
 
   uint8_t  rfAudioBoost   = data[9U];
   uint8_t  maxDev         = data[10U];
   uint8_t  rxLevel        = data[11U];
 
-  return fm.setMisc(timeout, timeoutLevel, ctcssFrequency, ctcssHighThreshold, ctcssLowThreshold, ctcssLevel, kerchunkTime, hangTime, accessMode, cosInvert, rfAudioBoost, maxDev, rxLevel);
+  uint8_t  squelchHighThreshold = data[12U];
+  uint8_t  squelchLowThreshold  = data[13U];
+
+  return fm.setMisc(timeout, timeoutLevel, ctcssFrequency, ctcssHighThreshold, ctcssLowThreshold, ctcssLevel, kerchunkTime, hangTime, accessMode, cosInvert, noiseSquelch, squelchHighThreshold, squelchLowThreshold, rfAudioBoost, maxDev, rxLevel);
 }
 
-uint8_t CSerialPort::setMode(const uint8_t* data, uint8_t length)
+uint8_t CSerialPort::setFMParams4(const uint8_t* data, uint16_t length)
+{
+  if (length < 4U)
+    return 4U;
+
+  uint8_t  audioBoost = data[0U];
+  uint8_t  speed      = data[1U];
+  uint16_t frequency  = data[2U] * 10U;
+  uint8_t  level      = data[3U];
+
+  char ack[50U];
+  uint8_t n = 0U;
+  for (uint8_t i = 4U; i < length; i++, n++)
+    ack[n] = data[i];
+  ack[n] = '\0';
+
+  return fm.setExt(ack, audioBoost, speed, frequency, level);
+}
+
+uint8_t CSerialPort::setMode(const uint8_t* data, uint16_t length)
 {
   if (length < 1U)
     return 4U;
@@ -600,7 +629,7 @@ void CSerialPort::setMode(MMDVM_STATE modemState)
 
 void CSerialPort::start()
 {
-  beginInt(1U, 115200);
+  beginInt(1U, SERIAL_SPEED);
 
 #if defined(SERIAL_REPEATER)
   beginInt(3U, 9600);
@@ -618,15 +647,25 @@ void CSerialPort::process()
         m_buffer[0U] = c;
         m_ptr = 1U;
         m_len = 0U;
-      }
+      } else {
-      else {
         m_ptr = 0U;
         m_len = 0U;
       }
     } else if (m_ptr == 1U) {
-      // Handle the frame length
+      // Handle the frame length, 1/2
       m_len = m_buffer[m_ptr] = c;
       m_ptr = 2U;
+    } else if (m_ptr == 2U) {
+      // Handle the frame length, 2/2
+      m_buffer[m_ptr] = c;
+      m_ptr = 3U;
+
+      if (m_len == 0U)
+        m_len = c + 255U;
+
+      // The full packet has been received, process it
+      if (m_ptr == m_len)
+        processMessage(m_buffer + 3U, m_len - 3U);
     } else {
       // Any other bytes are added to the buffer
       m_buffer[m_ptr] = c;
@@ -634,6 +673,41 @@ void CSerialPort::process()
 
       // The full packet has been received, process it
       if (m_ptr == m_len) {
+        if (m_len > 255U)
+          processMessage(m_buffer + 4U, m_len - 4U);
+        else
+          processMessage(m_buffer + 3U, m_len - 3U);
+      }
+    }
+  }
+
+  if (io.getWatchdog() >= 48000U) {
+    m_ptr = 0U;
+    m_len = 0U;
+  }
+
+#if defined(SERIAL_REPEATER)
+  // Write any outgoing serial data
+  uint16_t space = m_repeat.getData();
+  if (space > 0U) {
+    int avail = availableForWriteInt(3U);
+    if (avail < space)
+      space = avail;
+
+    for (uint16_t i = 0U; i < space; i++) {
+      uint8_t c = m_repeat.get();
+      writeInt(3U, &c, 1U);
+    }
+  }
+
+  // Read any incoming serial data
+  while (availableInt(3U))
+    readInt(3U);
+#endif
+}
+
+void CSerialPort::processMessage(const uint8_t* buffer, uint16_t length)
+{
   uint8_t err = 2U;
 
   switch (m_buffer[2U]) {
@@ -646,7 +720,7 @@ void CSerialPort::process()
       break;
 
     case MMDVM_SET_CONFIG:
-            err = setConfig(m_buffer + 3U, m_len - 3U);
+      err = setConfig(buffer, length);
       if (err == 0U)
         sendACK();
       else
@@ -654,7 +728,7 @@ void CSerialPort::process()
       break;
 
     case MMDVM_SET_MODE:
-            err = setMode(m_buffer + 3U, m_len - 3U);
+      err = setMode(buffer, length);
       if (err == 0U)
         sendACK();
       else
@@ -666,7 +740,7 @@ void CSerialPort::process()
       break;
 
     case MMDVM_FM_PARAMS1:
-            err = setFMParams1(m_buffer + 3U, m_len - 3U);
+      err = setFMParams1(buffer, length);
       if (err == 0U) {
         sendACK();
       } else {
@@ -676,7 +750,7 @@ void CSerialPort::process()
       break;
 
     case MMDVM_FM_PARAMS2:
-            err = setFMParams2(m_buffer + 3U, m_len - 3U);
+      err = setFMParams2(buffer, length);
       if (err == 0U) {
         sendACK();
       } else {
@@ -686,7 +760,7 @@ void CSerialPort::process()
       break;
 
     case MMDVM_FM_PARAMS3:
-            err = setFMParams3(m_buffer + 3U, m_len - 3U);
+      err = setFMParams3(buffer, length);
       if (err == 0U) {
         sendACK();
       } else {
@@ -695,19 +769,29 @@ void CSerialPort::process()
       }
       break;
 
+    case MMDVM_FM_PARAMS4:
+      err = setFMParams4(buffer, length);
+      if (err == 0U) {
+        sendACK();
+      } else {
+        DEBUG2("Received invalid FM params 4", err);
+        sendNAK(err);
+      }
+      break;
+
     case MMDVM_CAL_DATA:
       if (m_modemState == STATE_DSTARCAL)
-              err = calDStarTX.write(m_buffer + 3U, m_len - 3U);
+        err = calDStarTX.write(buffer, length);
       if (m_modemState == STATE_DMRCAL || m_modemState == STATE_LFCAL || m_modemState == STATE_DMRCAL1K || m_modemState == STATE_DMRDMO1K)
-              err = calDMR.write(m_buffer + 3U, m_len - 3U);
+        err = calDMR.write(buffer, length);
       if (m_modemState == STATE_FMCAL10K || m_modemState == STATE_FMCAL12K || m_modemState == STATE_FMCAL15K || m_modemState == STATE_FMCAL20K || m_modemState == STATE_FMCAL25K || m_modemState == STATE_FMCAL30K)
-              err = calFM.write(m_buffer + 3U, m_len - 3U);
+        err = calFM.write(buffer, length);
       if (m_modemState == STATE_P25CAL1K)
-              err = calP25.write(m_buffer + 3U, m_len - 3U);
+        err = calP25.write(buffer, length);
       if (m_modemState == STATE_NXDNCAL1K)
-              err = calNXDN.write(m_buffer + 3U, m_len - 3U);
+        err = calNXDN.write(buffer, length);
       if (m_modemState == STATE_POCSAGCAL)
-              err = calPOCSAG.write(m_buffer + 3U, m_len - 3U);
+        err = calPOCSAG.write(buffer, length);
       if (err == 0U) {
         sendACK();
       } else {
@@ -719,7 +803,7 @@ void CSerialPort::process()
     case MMDVM_SEND_CWID:
       err = 5U;
       if (m_modemState == STATE_IDLE)
-              err = cwIdTX.write(m_buffer + 3U, m_len - 3U);
+        err = cwIdTX.write(buffer, length);
       if (err != 0U) {
         DEBUG2("Invalid CW Id data", err);
         sendNAK(err);
@@ -729,7 +813,7 @@ void CSerialPort::process()
     case MMDVM_DSTAR_HEADER:
       if (m_dstarEnable) {
         if (m_modemState == STATE_IDLE || m_modemState == STATE_DSTAR)
-                err = dstarTX.writeHeader(m_buffer + 3U, m_len - 3U);
+          err = dstarTX.writeHeader(buffer, length);
       }
       if (err == 0U) {
         if (m_modemState == STATE_IDLE)
@@ -743,7 +827,7 @@ void CSerialPort::process()
     case MMDVM_DSTAR_DATA:
       if (m_dstarEnable) {
         if (m_modemState == STATE_IDLE || m_modemState == STATE_DSTAR)
-                err = dstarTX.writeData(m_buffer + 3U, m_len - 3U);
+          err = dstarTX.writeData(buffer, length);
       }
       if (err == 0U) {
         if (m_modemState == STATE_IDLE)
@@ -772,7 +856,7 @@ void CSerialPort::process()
       if (m_dmrEnable) {
         if (m_modemState == STATE_IDLE || m_modemState == STATE_DMR) {
           if (m_duplex)
-                  err = dmrTX.writeData1(m_buffer + 3U, m_len - 3U);
+            err = dmrTX.writeData1(buffer, length);
         }
       }
       if (err == 0U) {
@@ -788,9 +872,9 @@ void CSerialPort::process()
       if (m_dmrEnable) {
         if (m_modemState == STATE_IDLE || m_modemState == STATE_DMR) {
           if (m_duplex)
-                  err = dmrTX.writeData2(m_buffer + 3U, m_len - 3U);
+            err = dmrTX.writeData2(buffer, length);
           else
-                  err = dmrDMOTX.writeData(m_buffer + 3U, m_len - 3U);
+            err = dmrDMOTX.writeData(buffer, length);
         }
       }
       if (err == 0U) {
@@ -825,7 +909,7 @@ void CSerialPort::process()
 
     case MMDVM_DMR_SHORTLC:
       if (m_dmrEnable)
-              err = dmrTX.writeShortLC(m_buffer + 3U, m_len - 3U);
+        err = dmrTX.writeShortLC(buffer, length);
       if (err != 0U) {
         DEBUG2("Received invalid DMR Short LC", err);
         sendNAK(err);
@@ -834,7 +918,7 @@ void CSerialPort::process()
 
     case MMDVM_DMR_ABORT:
       if (m_dmrEnable)
-              err = dmrTX.writeAbort(m_buffer + 3U, m_len - 3U);
+        err = dmrTX.writeAbort(buffer, length);
       if (err != 0U) {
         DEBUG2("Received invalid DMR Abort", err);
         sendNAK(err);
@@ -844,7 +928,7 @@ void CSerialPort::process()
     case MMDVM_YSF_DATA:
       if (m_ysfEnable) {
         if (m_modemState == STATE_IDLE || m_modemState == STATE_YSF)
-                err = ysfTX.writeData(m_buffer + 3U, m_len - 3U);
+          err = ysfTX.writeData(buffer, length);
       }
       if (err == 0U) {
         if (m_modemState == STATE_IDLE)
@@ -858,7 +942,7 @@ void CSerialPort::process()
     case MMDVM_P25_HDR:
       if (m_p25Enable) {
         if (m_modemState == STATE_IDLE || m_modemState == STATE_P25)
-                err = p25TX.writeData(m_buffer + 3U, m_len - 3U);
+          err = p25TX.writeData(buffer, length);
       }
       if (err == 0U) {
         if (m_modemState == STATE_IDLE)
@@ -872,7 +956,7 @@ void CSerialPort::process()
     case MMDVM_P25_LDU:
       if (m_p25Enable) {
         if (m_modemState == STATE_IDLE || m_modemState == STATE_P25)
-                err = p25TX.writeData(m_buffer + 3U, m_len - 3U);
+          err = p25TX.writeData(buffer, length);
       }
       if (err == 0U) {
         if (m_modemState == STATE_IDLE)
@@ -886,7 +970,7 @@ void CSerialPort::process()
     case MMDVM_NXDN_DATA:
       if (m_nxdnEnable) {
         if (m_modemState == STATE_IDLE || m_modemState == STATE_NXDN)
-                err = nxdnTX.writeData(m_buffer + 3U, m_len - 3U);
+          err = nxdnTX.writeData(buffer, length);
       }
       if (err == 0U) {
         if (m_modemState == STATE_IDLE)
@@ -900,7 +984,7 @@ void CSerialPort::process()
     case MMDVM_M17_DATA:
       if (m_m17Enable) {
         if (m_modemState == STATE_IDLE || m_modemState == STATE_M17)
-                err = m17TX.writeData(m_buffer + 3U, m_len - 3U);
+          err = m17TX.writeData(buffer, length);
       }
       if (err == 0U) {
         if (m_modemState == STATE_IDLE)
@@ -914,7 +998,7 @@ void CSerialPort::process()
     case MMDVM_POCSAG_DATA:
       if (m_pocsagEnable) {
         if (m_modemState == STATE_IDLE || m_modemState == STATE_POCSAG)
-                err = pocsagTX.writeData(m_buffer + 3U, m_len - 3U);
+          err = pocsagTX.writeData(buffer, length);
       }
       if (err == 0U) {
         if (m_modemState == STATE_IDLE)
@@ -925,6 +1009,31 @@ void CSerialPort::process()
       }
       break;
 
+    case MMDVM_FM_DATA:
+      if (m_fmEnable) {
+        if (m_modemState == STATE_IDLE || m_modemState == STATE_FM)
+          err = fm.writeData(m_buffer + 3U, m_len - 3U);
+      }
+      if (err == 0U) {
+        if (m_modemState == STATE_IDLE)
+          setMode(STATE_FM);
+      } else {
+        DEBUG2("Received invalid FM data", err);
+        sendNAK(err);
+      }
+      break;
+
+    case MMDVM_AX25_DATA:
+      if (m_ax25Enable) {
+        if (m_modemState == STATE_IDLE || m_modemState == STATE_FM)
+          err = ax25TX.writeData(buffer, length);
+      }
+      if (err != 0U) {
+        DEBUG2("Received invalid AX.25 data", err);
+        sendNAK(err);
+      }
+      break;
+
     case MMDVM_TRANSPARENT:
     case MMDVM_QSO_INFO:
       // Do nothing on the MMDVM.
@@ -946,33 +1055,6 @@ void CSerialPort::process()
 
   m_ptr = 0U;
   m_len = 0U;
-      }
-    }
-  }
-
-  if (io.getWatchdog() >= 48000U) {
-    m_ptr = 0U;
-    m_len = 0U;
-  }
-
-#if defined(SERIAL_REPEATER)
-  // Write any outgoing serial data
-  uint16_t space = m_repeat.getData();
-  if (space > 0U) {
-    int avail = availableForWriteInt(3U);
-    if (avail < space)
-      space = avail;
-
-    for (uint16_t i = 0U; i < space; i++) {
-      uint8_t c = m_repeat.get();
-      writeInt(3U, &c, 1U);
-    }
-  }
-
-  // Read any incoming serial data
-  while (availableInt(3U))
-    readInt(3U);
-#endif
 }
 
 void CSerialPort::writeDStarHeader(const uint8_t* header, uint8_t length)
@@ -1277,6 +1359,105 @@ void CSerialPort::writeM17Lost()
   writeInt(1U, reply, 3);
 }
 
+void CSerialPort::writeFMData(const uint8_t* data, uint16_t length)
+{
+  if (m_modemState != STATE_FM && m_modemState != STATE_IDLE)
+    return;
+
+  if (!m_fmEnable)
+    return;
+
+  uint8_t reply[512U];
+
+  reply[0U] = MMDVM_FRAME_START;
+
+  if (length > 252U) {
+    reply[1U] = 0U;
+    reply[2U] = (length + 4U) - 255U;
+    reply[3U] = MMDVM_FM_DATA;
+
+    for (uint8_t i = 0U; i < length; i++)
+      reply[i + 4U] = data[i];
+
+    writeInt(1U, reply, length + 4U);
+  } else {
+    reply[1U] = length + 3U;
+    reply[2U] = MMDVM_FM_DATA;
+
+    for (uint8_t i = 0U; i < length; i++)
+      reply[i + 3U] = data[i];
+
+    writeInt(1U, reply, length + 3U);
+  }
+}
+
+void CSerialPort::writeFMStatus(uint8_t status)
+{
+  if (m_modemState != STATE_FM && m_modemState != STATE_IDLE)
+    return;
+
+  if (!m_fmEnable)
+    return;
+
+  uint8_t reply[10U];
+
+  reply[0U] = MMDVM_FRAME_START;
+  reply[1U] = 4U;
+  reply[2U] = MMDVM_FM_STATUS;
+  reply[3U] = status;
+
+  writeInt(1U, reply, 4U);
+}
+
+void CSerialPort::writeFMEOT()
+{
+  if (m_modemState != STATE_FM && m_modemState != STATE_IDLE)
+    return;
+
+  if (!m_fmEnable)
+    return;
+
+  uint8_t reply[10U];
+
+  reply[0U] = MMDVM_FRAME_START;
+  reply[1U] = 3U;
+  reply[2U] = MMDVM_FM_EOT;
+
+  writeInt(1U, reply, 3U);
+}
+
+void CSerialPort::writeAX25Data(const uint8_t* data, uint16_t length)
+{
+  if (m_modemState != STATE_FM && m_modemState != STATE_IDLE)
+    return;
+
+  if (!m_ax25Enable)
+    return;
+
+  uint8_t reply[512U];
+
+  reply[0U] = MMDVM_FRAME_START;
+
+  if (length > 252U) {
+    reply[1U] = 0U;
+    reply[2U] = (length + 4U) - 255U;
+    reply[3U] = MMDVM_AX25_DATA;
+
+    for (uint8_t i = 0U; i < length; i++)
+      reply[i + 4U] = data[i];
+
+    writeInt(1U, reply, length + 4U);
+  } else {
+    reply[1U] = length + 3U;
+    reply[2U] = MMDVM_AX25_DATA;
+
+    for (uint8_t i = 0U; i < length; i++)
+      reply[i + 3U] = data[i];
+
+    writeInt(1U, reply, length + 3U);
+  }
+}
+
 void CSerialPort::writeCalData(const uint8_t* data, uint8_t length)
 {
   if (m_modemState != STATE_DSTARCAL)
@@ -1446,3 +1627,4 @@ void CSerialPort::writeDebug(const char* text, int16_t n1, int16_t n2, int16_t n
 
   writeInt(1U, reply, count, true);
 }
+

SerialPort.h

@@ -21,7 +21,11 @@
 
 #include "Config.h"
 #include "Globals.h"
-#include "SerialRB.h"
+#include "RingBuffer.h"
+
+#if !defined(SERIAL_SPEED)
+#define SERIAL_SPEED 115200
+#endif
 
 
 class CSerialPort {
@@ -53,6 +57,12 @@ public:
   void writeM17Data(const uint8_t* data, uint8_t length);
   void writeM17Lost();
 
+  void writeAX25Data(const uint8_t* data, uint16_t length);
+
+  void writeFMData(const uint8_t* data, uint16_t length);
+  void writeFMStatus(uint8_t status);
+  void writeFMEOT();
+
   void writeCalData(const uint8_t* data, uint8_t length);
   void writeRSSIData(const uint8_t* data, uint8_t length);
 
@@ -63,22 +73,24 @@ public:
   void writeDebug(const char* text, int16_t n1, int16_t n2, int16_t n3, int16_t n4);
 
 private:
-  uint8_t   m_buffer[256U];
+  uint8_t   m_buffer[512U];
-  uint8_t   m_ptr;
+  uint16_t  m_ptr;
-  uint8_t   m_len;
+  uint16_t  m_len;
   bool      m_debug;
-  CSerialRB m_repeat;
+  CRingBuffer<uint8_t> m_repeat;
 
   void    sendACK();
   void    sendNAK(uint8_t err);
   void    getStatus();
   void    getVersion();
-  uint8_t setConfig(const uint8_t* data, uint8_t length);
+  uint8_t setConfig(const uint8_t* data, uint16_t length);
-  uint8_t setMode(const uint8_t* data, uint8_t length);
+  uint8_t setMode(const uint8_t* data, uint16_t length);
   void    setMode(MMDVM_STATE modemState);
-  uint8_t setFMParams1(const uint8_t* data, uint8_t length);
+  uint8_t setFMParams1(const uint8_t* data, uint16_t length);
-  uint8_t setFMParams2(const uint8_t* data, uint8_t length);
+  uint8_t setFMParams2(const uint8_t* data, uint16_t length);
-  uint8_t setFMParams3(const uint8_t* data, uint8_t length);
+  uint8_t setFMParams3(const uint8_t* data, uint16_t length);
+  uint8_t setFMParams4(const uint8_t* data, uint16_t length);
+  void    processMessage(const uint8_t* data, uint16_t length);
 
   // Hardware versions
   void    beginInt(uint8_t n, int speed);

SerialRB.cpp

@@ -1,100 +0,0 @@
-/*
-Serial RB control - Copyright (C) KI6ZUM 2015
-Copyright (C) 2015,2016 by Jonathan Naylor G4KLX
-
-This library is free software; you can redistribute it and/or
-modify it under the terms of the GNU Library General Public
-License as published by the Free Software Foundation; either
-version 2 of the License, or (at your option) any later version.
-
-This library is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-Library General Public License for more details.
-
-You should have received a copy of the GNU Library General Public
-License along with this library; if not, write to the
-Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
-Boston, MA  02110-1301, USA.
-*/
-
-#include "SerialRB.h"
-
-CSerialRB::CSerialRB(uint16_t length) :
-m_length(length),
-m_head(0U),
-m_tail(0U),
-m_full(false)
-{
-  m_buffer = new uint8_t[length];
-}
-
-void CSerialRB::reset()
-{
-  m_head = 0U;
-  m_tail = 0U;
-  m_full = false;
-}
-
-uint16_t CSerialRB::getSpace() const
-{
-  uint16_t n = 0U;
-
-  if (m_tail == m_head)
-    n = m_full ? 0U : m_length;
-  else if (m_tail < m_head)
-    n = m_length - m_head + m_tail;
-  else
-    n = m_tail - m_head;
-
-  if (n > m_length)
-    n = 0U;
-
-  return n;
-}
-
-uint16_t CSerialRB::getData() const
-{
-  if (m_tail == m_head)
-    return m_full ? m_length : 0U;
-  else if (m_tail < m_head)
-    return m_head - m_tail;
-  else
-    return m_length - m_tail + m_head;
-}
-
-bool CSerialRB::put(uint8_t c)
-{
-  if (m_full)
-    return false;
-
-  m_buffer[m_head] = c;
-
-  m_head++;
-  if (m_head >= m_length)
-    m_head = 0U;
-
-  if (m_head == m_tail)
-    m_full = true;
-
-  return true;
-}
-
-uint8_t CSerialRB::peek() const
-{
-  return m_buffer[m_tail];
-}
-
-uint8_t CSerialRB::get()
-{
-  uint8_t value = m_buffer[m_tail];
-
-  m_full = false;
-
-  m_tail++;
-  if (m_tail >= m_length)
-    m_tail = 0U;
-
-  return value;
-}
-

SerialRB.h

@@ -1,62 +0,0 @@
-/*
-Serial fifo control - Copyright (C) KI6ZUM 2015
-Copyright (C) 2015,2016 by Jonathan Naylor G4KLX
-
-This library is free software; you can redistribute it and/or
-modify it under the terms of the GNU Library General Public
-License as published by the Free Software Foundation; either
-version 2 of the License, or (at your option) any later version.
-
-This library is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-Library General Public License for more details.
-
-You should have received a copy of the GNU Library General Public
-License along with this library; if not, write to the
-Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
-Boston, MA  02110-1301, USA.
-*/
-
-#if !defined(SERIALRB_H)
-#define  SERIALRB_H
-
-#if defined(STM32F4XX)
-#include "stm32f4xx.h"
-#elif defined(STM32F7XX)
-#include "stm32f7xx.h"
-#elif defined(STM32F105xC)
-#include "stm32f1xx.h"
-#include <cstddef>
-#else
-#include <Arduino.h>
-#endif
-
-const uint16_t SERIAL_RINGBUFFER_SIZE = 370U;
-
-class CSerialRB {
-public:
-  CSerialRB(uint16_t length = SERIAL_RINGBUFFER_SIZE);
-
-  uint16_t getSpace() const;
-
-  uint16_t getData() const;
-
-  void reset();
-
-  bool put(uint8_t c);
-
-  uint8_t peek() const;
-
-  uint8_t get();
-
-private:
-  uint16_t          m_length;
-  volatile uint8_t* m_buffer;
-  volatile uint16_t m_head;
-  volatile uint16_t m_tail;
-  volatile bool     m_full;
-};
-
-#endif
-

SerialSTM.cpp

@@ -39,9 +39,7 @@ UART5  - TXD PC12 - RXD PD2 (Discovery, MMDVM-Pi, MMDVM-Pi F722 board, MMDVM-F4M
 
 #if defined(STM32F4XX) || defined(STM32F7XX)
 
-#define TX_SERIAL_FIFO_SIZE 512U
+#include "STMUART.h"
-#define RX_SERIAL_FIFO_SIZE 512U
-
 extern "C" {
    void USART1_IRQHandler();
    void USART2_IRQHandler();
@@ -52,111 +50,12 @@ extern "C" {
 /* ************* USART1 ***************** */
 #if defined(STM32F4_PI) || defined(STM32F4_F4M) || defined(STM32F722_F7M) || defined(STM32F722_PI) || defined(STM32F722_RPT_HAT) || defined(STM32F4_DVM) || (defined(STM32F4_NUCLEO) && defined(STM32F4_NUCLEO_ARDUINO_HEADER)) || defined(DRCC_DVM) || defined(STM32F4_EDA_405) || defined(STM32F4_EDA_446)
 
-volatile uint8_t  TXSerialfifo1[TX_SERIAL_FIFO_SIZE];
-volatile uint8_t  RXSerialfifo1[RX_SERIAL_FIFO_SIZE];
-volatile uint16_t TXSerialfifohead1, TXSerialfifotail1;
-volatile uint16_t RXSerialfifohead1, RXSerialfifotail1;
 
-// Init queues
+static CSTMUART m_USART1;
-void TXSerialfifoinit1()
-{
-   TXSerialfifohead1 = 0U;
-   TXSerialfifotail1 = 0U;
-}
-
-void RXSerialfifoinit1()
-{
-   RXSerialfifohead1 = 0U;
-   RXSerialfifotail1 = 0U;
-}
-
-// How full is queue
-// TODO decide if how full or how empty is preferred info to return
-uint16_t TXSerialfifolevel1()
-{
-   uint32_t tail = TXSerialfifotail1;
-   uint32_t head = TXSerialfifohead1;
-
-   if (tail > head)
-      return TX_SERIAL_FIFO_SIZE + head - tail;
-   else
-      return head - tail;
-}
-
-uint16_t RXSerialfifolevel1()
-{
-   uint32_t tail = RXSerialfifotail1;
-   uint32_t head = RXSerialfifohead1;
-
-   if (tail > head)
-      return RX_SERIAL_FIFO_SIZE + head - tail;
-   else
-      return head - tail;
-}
-
-// Flushes the transmit shift register
-// warning: this call is blocking
-void TXSerialFlush1()
-{
-   // wait until the TXE shows the shift register is empty
-   while (USART_GetITStatus(USART1, USART_FLAG_TXE))
-      ;
-}
-
-uint8_t TXSerialfifoput1(uint8_t next)
-{
-   if (TXSerialfifolevel1() < TX_SERIAL_FIFO_SIZE) {
-      TXSerialfifo1[TXSerialfifohead1] = next;
-
-      TXSerialfifohead1++;
-      if (TXSerialfifohead1 >= TX_SERIAL_FIFO_SIZE)
-         TXSerialfifohead1 = 0U;
-
-      // make sure transmit interrupts are enabled as long as there is data to send
-      USART_ITConfig(USART1, USART_IT_TXE, ENABLE);
-      return 1U;
-   } else {
-      return 0U; // signal an overflow occurred by returning a zero count
-   }
-}
 
 void USART1_IRQHandler()
 {
-   uint8_t c;
+  m_USART1.handleIRQ();
-
-   if (USART_GetITStatus(USART1, USART_IT_RXNE)) {
-      c = (uint8_t) USART_ReceiveData(USART1);
-
-      if (RXSerialfifolevel1() < RX_SERIAL_FIFO_SIZE) {
-         RXSerialfifo1[RXSerialfifohead1] = c;
-
-         RXSerialfifohead1++;
-         if (RXSerialfifohead1 >= RX_SERIAL_FIFO_SIZE)
-            RXSerialfifohead1 = 0U;
-      } else {
-         // TODO - do something if rx fifo is full?
-      }
-
-      USART_ClearITPendingBit(USART1, USART_IT_RXNE);
-   }
-
-   if (USART_GetITStatus(USART1, USART_IT_TXE)) {
-      c = 0U;
-
-      if (TXSerialfifohead1 != TXSerialfifotail1) { // if the fifo is not empty
-         c = TXSerialfifo1[TXSerialfifotail1];
-
-         TXSerialfifotail1++;
-         if (TXSerialfifotail1 >= TX_SERIAL_FIFO_SIZE)
-            TXSerialfifotail1 = 0U;
-
-         USART_SendData(USART1, c);
-      } else { // if there's no more data to transmit then turn off TX interrupts
-         USART_ITConfig(USART1, USART_IT_TXE, DISABLE);
-      }
-
-      USART_ClearITPendingBit(USART1, USART_IT_TXE);
-   }
 }
 
 void InitUSART1(int speed)
@@ -201,41 +100,7 @@ void InitUSART1(int speed)
 
    USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);
 
-   // initialize the fifos
+   m_USART1.init(USART1);
-   TXSerialfifoinit1();
-   RXSerialfifoinit1();
-}
-
-uint8_t AvailUSART1()
-{
-   if (RXSerialfifolevel1() > 0U)
-      return 1U;
-   else
-      return 0U;
-}
-
-int AvailForWriteUSART1()
-{
-   return TX_SERIAL_FIFO_SIZE - TXSerialfifolevel1();
-}
-
-uint8_t ReadUSART1()
-{
-   uint8_t data_c = RXSerialfifo1[RXSerialfifotail1];
-
-   RXSerialfifotail1++;
-   if (RXSerialfifotail1 >= RX_SERIAL_FIFO_SIZE)
-      RXSerialfifotail1 = 0U;
-
-   return data_c;
-}
-
-void WriteUSART1(const uint8_t* data, uint16_t length)
-{
-   for (uint16_t i = 0U; i < length; i++)
-      TXSerialfifoput1(data[i]);
-
-   USART_ITConfig(USART1, USART_IT_TXE, ENABLE);
 }
 
 #endif
@@ -243,111 +108,12 @@ void WriteUSART1(const uint8_t* data, uint16_t length)
 /* ************* USART2 ***************** */
 #if defined(STM32F4_NUCLEO) || defined(STM32F4_RPT_HAT_TGO) || defined(DRCC_DVM)
 
-volatile uint8_t  TXSerialfifo2[TX_SERIAL_FIFO_SIZE];
+static CSTMUART m_USART2;
-volatile uint8_t  RXSerialfifo2[RX_SERIAL_FIFO_SIZE];
-volatile uint16_t TXSerialfifohead2, TXSerialfifotail2;
-volatile uint16_t RXSerialfifohead2, RXSerialfifotail2;
 
-// Init queues
-void TXSerialfifoinit2()
-{
-   TXSerialfifohead2 = 0U;
-   TXSerialfifotail2 = 0U;
-}
-
-void RXSerialfifoinit2()
-{
-   RXSerialfifohead2 = 0U;
-   RXSerialfifotail2 = 0U;
-}
-
-// How full is queue
-// TODO decide if how full or how empty is preferred info to return
-uint16_t TXSerialfifolevel2()
-{
-   uint32_t tail = TXSerialfifotail2;
-   uint32_t head = TXSerialfifohead2;
-
-   if (tail > head)
-      return TX_SERIAL_FIFO_SIZE + head - tail;
-   else
-      return head - tail;
-}
-
-uint16_t RXSerialfifolevel2()
-{
-   uint32_t tail = RXSerialfifotail2;
-   uint32_t head = RXSerialfifohead2;
-
-   if (tail > head)
-      return RX_SERIAL_FIFO_SIZE + head - tail;
-   else
-      return head - tail;
-}
-
-// Flushes the transmit shift register
-// warning: this call is blocking
-void TXSerialFlush2()
-{
-   // wait until the TXE shows the shift register is empty
-   while (USART_GetITStatus(USART2, USART_FLAG_TXE))
-      ;
-}
-
-uint8_t TXSerialfifoput2(uint8_t next)
-{
-   if (TXSerialfifolevel2() < TX_SERIAL_FIFO_SIZE) {
-      TXSerialfifo2[TXSerialfifohead2] = next;
-
-      TXSerialfifohead2++;
-      if (TXSerialfifohead2 >= TX_SERIAL_FIFO_SIZE)
-         TXSerialfifohead2 = 0U;
-
-      // make sure transmit interrupts are enabled as long as there is data to send
-      USART_ITConfig(USART2, USART_IT_TXE, ENABLE);
-      return 1U;
-   } else {
-      return 0U; // signal an overflow occurred by returning a zero count
-   }
-}
 
 void USART2_IRQHandler()
 {
-   uint8_t c;
+   m_USART2.handleIRQ();
-
-   if (USART_GetITStatus(USART2, USART_IT_RXNE)) {
-      c = (uint8_t) USART_ReceiveData(USART2);
-
-      if (RXSerialfifolevel2() < RX_SERIAL_FIFO_SIZE) {
-         RXSerialfifo2[RXSerialfifohead2] = c;
-
-         RXSerialfifohead2++;
-         if (RXSerialfifohead2 >= RX_SERIAL_FIFO_SIZE)
-            RXSerialfifohead2 = 0U;
-      } else {
-         // TODO - do something if rx fifo is full?
-      }
-
-      USART_ClearITPendingBit(USART2, USART_IT_RXNE);
-   }
-
-   if (USART_GetITStatus(USART2, USART_IT_TXE)) {
-      c = 0U;
-
-      if (TXSerialfifohead2 != TXSerialfifotail2) { // if the fifo is not empty
-         c = TXSerialfifo2[TXSerialfifotail2];
-
-         TXSerialfifotail2++;
-         if (TXSerialfifotail2 >= TX_SERIAL_FIFO_SIZE)
-            TXSerialfifotail2 = 0U;
-
-         USART_SendData(USART2, c);
-      } else { // if there's no more data to transmit then turn off TX interrupts
-         USART_ITConfig(USART2, USART_IT_TXE, DISABLE);
-      }
-
-      USART_ClearITPendingBit(USART2, USART_IT_TXE);
-   }
 }
 
 void InitUSART2(int speed)
@@ -392,41 +158,7 @@ void InitUSART2(int speed)
 
    USART_ITConfig(USART2, USART_IT_RXNE, ENABLE);
 
-   // initialize the fifos
+   m_USART2.init(USART2);
-   TXSerialfifoinit2();
-   RXSerialfifoinit2();
-}
-
-uint8_t AvailUSART2()
-{
-   if (RXSerialfifolevel2() > 0U)
-      return 1U;
-   else
-      return 0U;
-}
-
-int AvailForWriteUSART2()
-{
-   return TX_SERIAL_FIFO_SIZE - TXSerialfifolevel2();
-}
-
-uint8_t ReadUSART2()
-{
-   uint8_t data_c = RXSerialfifo2[RXSerialfifotail2];
-
-   RXSerialfifotail2++;
-   if (RXSerialfifotail2 >= RX_SERIAL_FIFO_SIZE)
-      RXSerialfifotail2 = 0U;
-
-   return data_c;
-}
-
-void WriteUSART2(const uint8_t* data, uint16_t length)
-{
-   for (uint16_t i = 0U; i < length; i++)
-      TXSerialfifoput2(data[i]);
-
-   USART_ITConfig(USART2, USART_IT_TXE, ENABLE);
 }
 
 #endif
@@ -434,111 +166,11 @@ void WriteUSART2(const uint8_t* data, uint16_t length)
 /* ************* USART3 ***************** */
 #if defined(STM32F4_DISCOVERY) || defined(STM32F7_NUCLEO)
 
-volatile uint8_t  TXSerialfifo3[TX_SERIAL_FIFO_SIZE];
+static CSTMUART m_USART3;
-volatile uint8_t  RXSerialfifo3[RX_SERIAL_FIFO_SIZE];
-volatile uint16_t TXSerialfifohead3, TXSerialfifotail3;
-volatile uint16_t RXSerialfifohead3, RXSerialfifotail3;
-
-// Init queues
-void TXSerialfifoinit3()
-{
-   TXSerialfifohead3 = 0U;
-   TXSerialfifotail3 = 0U;
-}
-
-void RXSerialfifoinit3()
-{
-   RXSerialfifohead3 = 0U;
-   RXSerialfifotail3 = 0U;
-}
-
-// How full is queue
-// TODO decide if how full or how empty is preferred info to return
-uint16_t TXSerialfifolevel3()
-{
-   uint32_t tail = TXSerialfifotail3;
-   uint32_t head = TXSerialfifohead3;
-
-   if (tail > head)
-      return TX_SERIAL_FIFO_SIZE + head - tail;
-   else
-      return head - tail;
-}
-
-uint16_t RXSerialfifolevel3()
-{
-   uint32_t tail = RXSerialfifotail3;
-   uint32_t head = RXSerialfifohead3;
-
-   if (tail > head)
-      return RX_SERIAL_FIFO_SIZE + head - tail;
-   else
-      return head - tail;
-}
-
-// Flushes the transmit shift register
-// warning: this call is blocking
-void TXSerialFlush3()
-{
-   // wait until the TXE shows the shift register is empty
-   while (USART_GetITStatus(USART3, USART_FLAG_TXE))
-      ;
-}
-
-uint8_t TXSerialfifoput3(uint8_t next)
-{
-   if (TXSerialfifolevel3() < TX_SERIAL_FIFO_SIZE) {
-      TXSerialfifo3[TXSerialfifohead3] = next;
-
-      TXSerialfifohead3++;
-      if (TXSerialfifohead3 >= TX_SERIAL_FIFO_SIZE)
-         TXSerialfifohead3 = 0U;
-
-      // make sure transmit interrupts are enabled as long as there is data to send
-      USART_ITConfig(USART3, USART_IT_TXE, ENABLE);
-      return 1U;
-   } else {
-      return 0U; // signal an overflow occurred by returning a zero count
-   }
-}
 
 void USART3_IRQHandler()
 {
-   uint8_t c;
+   m_USART3.handleIRQ();
-
-   if (USART_GetITStatus(USART3, USART_IT_RXNE)) {
-      c = (uint8_t) USART_ReceiveData(USART3);
-
-      if (RXSerialfifolevel3() < RX_SERIAL_FIFO_SIZE) {
-         RXSerialfifo3[RXSerialfifohead3] = c;
-
-         RXSerialfifohead3++;
-         if (RXSerialfifohead3 >= RX_SERIAL_FIFO_SIZE)
-            RXSerialfifohead3 = 0U;
-      } else {
-         // TODO - do something if rx fifo is full?
-      }
-
-      USART_ClearITPendingBit(USART3, USART_IT_RXNE);
-   }
-
-   if (USART_GetITStatus(USART3, USART_IT_TXE)) {
-      c = 0U;
-
-      if (TXSerialfifohead3 != TXSerialfifotail3) { // if the fifo is not empty
-         c = TXSerialfifo3[TXSerialfifotail3];
-
-         TXSerialfifotail3++;
-         if (TXSerialfifotail3 >= TX_SERIAL_FIFO_SIZE)
-            TXSerialfifotail3 = 0U;
-
-         USART_SendData(USART3, c);
-      } else { // if there's no more data to transmit then turn off TX interrupts
-         USART_ITConfig(USART3, USART_IT_TXE, DISABLE);
-      }
-
-      USART_ClearITPendingBit(USART3, USART_IT_TXE);
-   }
 }
 
 #if defined(STM32F7_NUCLEO)
@@ -600,41 +232,7 @@ void InitUSART3(int speed)
 
    USART_ITConfig(USART3, USART_IT_RXNE, ENABLE);
 
-   // initialize the fifos
+   m_USART3.init(USART3);
-   TXSerialfifoinit3();
-   RXSerialfifoinit3();
-}
-
-uint8_t AvailUSART3()
-{
-   if (RXSerialfifolevel3() > 0U)
-      return 1U;
-   else
-      return 0U;
-}
-
-int AvailForWriteUSART3()
-{
-   return TX_SERIAL_FIFO_SIZE - TXSerialfifolevel3();
-}
-
-uint8_t ReadUSART3()
-{
-   uint8_t data_c = RXSerialfifo3[RXSerialfifotail3];
-
-   RXSerialfifotail3++;
-   if (RXSerialfifotail3 >= RX_SERIAL_FIFO_SIZE)
-      RXSerialfifotail3 = 0U;
-
-   return data_c;
-}
-
-void WriteUSART3(const uint8_t* data, uint16_t length)
-{
-   for (uint16_t i = 0U; i < length; i++)
-      TXSerialfifoput3(data[i]);
-
-   USART_ITConfig(USART3, USART_IT_TXE, ENABLE);
 }
 
 #endif
@@ -642,111 +240,11 @@ void WriteUSART3(const uint8_t* data, uint16_t length)
 /* ************* UART5 ***************** */
 #if !(defined(STM32F4_NUCLEO) && defined(STM32F4_NUCLEO_ARDUINO_HEADER))
 
-volatile uint8_t  TXSerialfifo5[TX_SERIAL_FIFO_SIZE];
+static CSTMUART m_UART5;
-volatile uint8_t  RXSerialfifo5[RX_SERIAL_FIFO_SIZE];
-volatile uint16_t TXSerialfifohead5, TXSerialfifotail5;
-volatile uint16_t RXSerialfifohead5, RXSerialfifotail5;
-
-// Init queues
-void TXSerialfifoinit5()
-{
-   TXSerialfifohead5 = 0U;
-   TXSerialfifotail5 = 0U;
-}
-
-void RXSerialfifoinit5()
-{
-   RXSerialfifohead5 = 0U;
-   RXSerialfifotail5 = 0U;
-}
-
-// How full is queue
-// TODO decide if how full or how empty is preferred info to return
-uint16_t TXSerialfifolevel5()
-{
-   uint32_t tail = TXSerialfifotail5;
-   uint32_t head = TXSerialfifohead5;
-
-   if (tail > head)
-      return TX_SERIAL_FIFO_SIZE + head - tail;
-   else
-      return head - tail;
-}
-
-uint16_t RXSerialfifolevel5()
-{
-   uint32_t tail = RXSerialfifotail5;
-   uint32_t head = RXSerialfifohead5;
-
-   if (tail > head)
-      return RX_SERIAL_FIFO_SIZE + head - tail;
-   else
-      return head - tail;
-}
-
-// Flushes the transmit shift register
-// warning: this call is blocking
-void TXSerialFlush5()
-{
-   // wait until the TXE shows the shift register is empty
-   while (USART_GetITStatus(UART5, USART_FLAG_TXE))
-      ;
-}
-
-uint8_t TXSerialfifoput5(uint8_t next)
-{
-   if (TXSerialfifolevel5() < TX_SERIAL_FIFO_SIZE) {
-      TXSerialfifo5[TXSerialfifohead5] = next;
-
-      TXSerialfifohead5++;
-      if (TXSerialfifohead5 >= TX_SERIAL_FIFO_SIZE)
-         TXSerialfifohead5 = 0U;
-
-      // make sure transmit interrupts are enabled as long as there is data to send
-      USART_ITConfig(UART5, USART_IT_TXE, ENABLE);
-      return 1U;
-   } else {
-      return 0U; // signal an overflow occurred by returning a zero count
-   }
-}
 
 void UART5_IRQHandler()
 {
-   uint8_t c;
+   m_UART5.handleIRQ();
-
-   if (USART_GetITStatus(UART5, USART_IT_RXNE)) {
-      c = (uint8_t) USART_ReceiveData(UART5);
-
-      if (RXSerialfifolevel5() < RX_SERIAL_FIFO_SIZE) {
-         RXSerialfifo5[RXSerialfifohead5] = c;
-
-         RXSerialfifohead5++;
-         if (RXSerialfifohead5 >= RX_SERIAL_FIFO_SIZE)
-            RXSerialfifohead5 = 0U;
-      } else {
-         // TODO - do something if rx fifo is full?
-      }
-
-      USART_ClearITPendingBit(UART5, USART_IT_RXNE);
-   }
-
-   if (USART_GetITStatus(UART5, USART_IT_TXE)) {
-      c = 0U;
-
-      if (TXSerialfifohead5 != TXSerialfifotail5) { // if the fifo is not empty
-         c = TXSerialfifo5[TXSerialfifotail5];
-
-         TXSerialfifotail5++;
-         if (TXSerialfifotail5 >= TX_SERIAL_FIFO_SIZE)
-            TXSerialfifotail5 = 0U;
-
-         USART_SendData(UART5, c);
-      } else { // if there's no more data to transmit then turn off TX interrupts
-      USART_ITConfig(UART5, USART_IT_TXE, DISABLE);
-      }
-
-      USART_ClearITPendingBit(UART5, USART_IT_TXE);
-   }
 }
 
 void InitUART5(int speed)
@@ -795,41 +293,7 @@ void InitUART5(int speed)
 
    USART_ITConfig(UART5, USART_IT_RXNE, ENABLE);
 
-   // initialize the fifos
+   m_UART5.init(UART5);
-   TXSerialfifoinit5();
-   RXSerialfifoinit5();
-}
-
-uint8_t AvailUART5()
-{
-   if (RXSerialfifolevel5() > 0U)
-      return 1U;
-   else
-      return 0U;
-}
-
-int AvailForWriteUART5()
-{
-   return TX_SERIAL_FIFO_SIZE - TXSerialfifolevel5();
-}
-
-uint8_t ReadUART5()
-{
-   uint8_t data_c = RXSerialfifo5[RXSerialfifotail5];
-
-   RXSerialfifotail5++;
-   if (RXSerialfifotail5 >= RX_SERIAL_FIFO_SIZE)
-      RXSerialfifotail5 = 0U;
-
-   return data_c;
-}
-
-void WriteUART5(const uint8_t* data, uint16_t length)
-{
-   for (uint16_t i = 0U; i < length; i++)
-      TXSerialfifoput5(data[i]);
-
-   USART_ITConfig(UART5, USART_IT_TXE, ENABLE);
 }
 
 #endif
@@ -868,21 +332,21 @@ int CSerialPort::availableInt(uint8_t n)
    switch (n) {
       case 1U:
          #if defined(STM32F4_DISCOVERY) || defined(STM32F7_NUCLEO)
-         return AvailUSART3();
+         return m_USART3.availble();//AvailUSART3();
          #elif defined(STM32F4_PI) || defined(STM32F4_F4M) || defined(STM32F722_PI) || defined(STM32F722_F7M) || defined(STM32F722_RPT_HAT) || defined(STM32F4_DVM) || defined(STM32F4_EDA_405) || defined(STM32F4_EDA_446)
-         return AvailUSART1();
+         return m_USART1.available();//AvailUSART1();
          #elif defined(STM32F4_NUCLEO) || defined(STM32F4_RPT_HAT_TGO)
-         return AvailUSART2();
+         return m_USART2.available();//AvailUSART2();
          #elif defined(DRCC_DVM)
-         return AvailUSART1();
+         return m_USART1.available();//AvailUSART1();
          #endif
       case 3U:
          #if defined(STM32F4_NUCLEO) && defined(STM32F4_NUCLEO_ARDUINO_HEADER)
-         return AvailUSART1();
+         return m_USART1.available(); //AvailUSART1();
          #elif defined(DRCC_DVM)
-         return AvailUSART2();
+         return m_USART2.available(); //AvailUSART2();
          #else
-         return AvailUART5();
+         return m_UART5.available();//AvailUART5();
          #endif
       default:
          return 0;
@@ -894,21 +358,21 @@ int CSerialPort::availableForWriteInt(uint8_t n)
    switch (n) {
       case 1U:
          #if defined(STM32F4_DISCOVERY) || defined(STM32F7_NUCLEO)
-         return AvailForWriteUSART3();
+         return m_USART3.availableForWrite(); //AvailForWriteUSART3();
          #elif defined(STM32F4_PI) || defined(STM32F4_F4M) || defined(STM32F722_PI) || defined(STM32F722_F7M) || defined(STM32F722_RPT_HAT) || defined(STM32F4_DVM) || defined(STM32F4_EDA_405) || defined(STM32F4_EDA_446)
-         return AvailForWriteUSART1();
+         return m_USART1.availableForWrite(); //AvailForWriteUSART1();
          #elif defined(STM32F4_NUCLEO) || defined(STM32F4_RPT_HAT_TGO)
-         return AvailForWriteUSART2();
+         return m_USART2.availableForWrite();//AvailForWriteUSART2();
          #elif defined(DRCC_DVM)
-         return AvailForWriteUSART1();
+         return m_USART1.availableForWrite();//AvailForWriteUSART1();
          #endif
       case 3U:
          #if defined(STM32F4_NUCLEO) && defined(STM32F4_NUCLEO_ARDUINO_HEADER)
-         return AvailForWriteUSART1();
+         return m_USART1.availableForWrite(); //AvailForWriteUSART1();
          #elif defined(DRCC_DVM)
-         return AvailForWriteUSART2();
+         return m_USART2.availableForWrite();//AvailForWriteUSART2();
          #else
-         return AvailForWriteUART5();
+         return m_UART5.availableForWrite();//AvailForWriteUART5();
          #endif
       default:
          return 0;
@@ -920,21 +384,21 @@ uint8_t CSerialPort::readInt(uint8_t n)
    switch (n) {
       case 1U:
          #if defined(STM32F4_DISCOVERY) || defined(STM32F7_NUCLEO)
-         return ReadUSART3();
+         return m_USART3.read();//ReadUSART3();
          #elif defined(STM32F4_PI) || defined(STM32F4_F4M) || defined(STM32F722_PI) || defined(STM32F722_F7M) || defined(STM32F722_RPT_HAT) || defined(STM32F4_DVM) || defined(STM32F4_EDA_405) || defined(STM32F4_EDA_446)
-         return ReadUSART1();
+         return m_USART1.read();//ReadUSART1();
          #elif defined(STM32F4_NUCLEO) || defined(STM32F4_RPT_HAT_TGO)
-         return ReadUSART2();
+         return m_USART2.read();//ReadUSART2();
          #elif defined(DRCC_DVM)
-         return ReadUSART1();
+         return m_USART1.read();//ReadUSART1();
          #endif
       case 3U:
          #if defined(STM32F4_NUCLEO) && defined(STM32F4_NUCLEO_ARDUINO_HEADER)
-         return ReadUSART1();
+         return m_USART1.read();//ReadUSART1();
          #elif defined(DRCC_DVM)
-         return ReadUSART2();
+         return m_USART2.read();//ReadUSART2();
          #else
-         return ReadUART5();
+         return m_UART5.read();//ReadUART5();
          #endif
       default:
          return 0U;
@@ -946,36 +410,36 @@ void CSerialPort::writeInt(uint8_t n, const uint8_t* data, uint16_t length, bool
    switch (n) {
       case 1U:
          #if defined(STM32F4_DISCOVERY) || defined(STM32F7_NUCLEO)
-         WriteUSART3(data, length);
+         m_USART3.write(data, length); //WriteUSART3(data, length);
          if (flush)
-            TXSerialFlush3();
+            m_USART3.flush();//TXSerialFlush3();
          #elif defined(STM32F4_PI) || defined(STM32F4_F4M) || defined(STM32F722_PI) || defined(STM32F722_F7M) || defined(STM32F722_RPT_HAT) || defined(STM32F4_DVM) || defined(STM32F4_EDA_405) || defined(STM32F4_EDA_446)
-         WriteUSART1(data, length);
+         m_USART1.write(data, length);//WriteUSART1(data, length);
          if (flush)
-            TXSerialFlush1();
+            m_USART1.flush();//TXSerialFlush1();
          #elif defined(STM32F4_NUCLEO) || defined(STM32F4_RPT_HAT_TGO)
-         WriteUSART2(data, length);
+         m_USART2.write(data, length);//WriteUSART2(data, length);
          if (flush)
-            TXSerialFlush2();
+            m_USART2.flush();//TXSerialFlush2();
          #elif defined(DRCC_DVM)
-         WriteUSART1(data, length);
+         m_USART1.write(data, length);//WriteUSART1(data, length);
          if (flush)
-            TXSerialFlush1();
+            m_USART1.flush();//TXSerialFlush1();
          #endif
          break;
       case 3U:
          #if defined(STM32F4_NUCLEO) && defined(STM32F4_NUCLEO_ARDUINO_HEADER)
-         WriteUSART1(data, length);
+         m_USART1.write(data, length); //WriteUSART1(data, length);
          if (flush)
-            TXSerialFlush1();
+            m_USART1.flush();
          #elif defined(DRCC_DVM)
-         WriteUSART2(data, length);
+         m_USART2.write(data, length);//WriteUSART2(data, length);
          if (flush)
-            TXSerialFlush2();
+            m_USART2.flush();//TXSerialFlush2();
          #else
-         WriteUART5(data, length);
+         m_UART5.write(data, length);//WriteUART5(data, length);
          if (flush)
-            TXSerialFlush5();
+            m_UART5.flush();//TXSerialFlush5();
          #endif
          break;
       default:
@@ -984,3 +448,4 @@ void CSerialPort::writeInt(uint8_t n, const uint8_t* data, uint16_t length, bool
 }
 
 #endif
+

Tools/FMGenerateFilterCoefficients.py

@@ -17,30 +17,30 @@ f2 = 2700
 rp = 0.2
 
 # scaling factor in bits, do not change !
-q = 0
+q = 15
 # scaling factor as facor...
 scaling_factor = 2**q
 
 # let's generate a sequence of 2nd order IIR filters
 sos = signal.cheby1(3,rp,[f1, f2],'bandpass', output='sos', fs=fs)
-#sos = signal.cheby1(1, rp, 2122, 'lowpass', output='sos', fs=fs) #deemphasis filter
+#os = signal.cheby1(4, rp, f2, 'lowpass', output='sos', fs=fs) #deemphasis filter
 #sos = signal.cheby1(1, rp, 2122, 'highpass', output='sos', fs=fs) #deemphasis filter
 
-#sos = np.round((sos) * scaling_factor)
+sosrounded = np.round((sos) * scaling_factor)
 
 # print coefficients
-for biquad in sos:
+for biquad in sosrounded:
     for coeff in biquad:
-        #print(int(coeff),",",sep="",end="")
+        print(int(coeff),",",sep="",end="")
-        print((coeff),",",sep="",end="")
+        #print((coeff),",",sep="",end="")
     print("")
 
 # plot the frequency response
 b,a = signal.sos2tf(sos)
-w,h = signal.freqz(b,a)
+w,h = signal.freqz(b,a, worN=2048)
 pl.plot(w/np.pi/2*fs,20*np.log(np.abs(h)))
 pl.xlabel('frequency/Hz');
 pl.ylabel('gain/dB');
-pl.ylim(top=1,bottom=-20);
+pl.ylim(top=1,bottom=-30);
 pl.xlim(left=250, right=12000);
 pl.show()

YSFTX.cpp

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2018 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2018,2020 by Jonathan Naylor G4KLX
  *   Copyright (C) 2017 by Andy Uribe CA6JAU
  *
  *   This program is free software; you can redistribute it and/or modify
@@ -73,7 +73,8 @@ void CYSFTX::process()
         m_poBuffer[m_poLen++] = YSF_START_SYNC;
     } else {
       for (uint8_t i = 0U; i < YSF_FRAME_LENGTH_BYTES; i++) {
-        uint8_t c = m_buffer.get();
+        uint8_t c = 0U;
+        m_buffer.get(c);
         m_poBuffer[m_poLen++] = c;
       }
     }
@@ -116,7 +117,7 @@ void CYSFTX::process()
   }
 }
 
-uint8_t CYSFTX::writeData(const uint8_t* data, uint8_t length)
+uint8_t CYSFTX::writeData(const uint8_t* data, uint16_t length)
 {
   if (length != (YSF_FRAME_LENGTH_BYTES + 1U))
     return 4U;

YSFTX.h

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2015,2016,2017 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2015,2016,2017,2020 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -21,13 +21,13 @@
 
 #include "Config.h"
 
-#include "SerialRB.h"
+#include "RingBuffer.h"
 
 class CYSFTX {
 public:
   CYSFTX();
 
-  uint8_t writeData(const uint8_t* data, uint8_t length);
+  uint8_t writeData(const uint8_t* data, uint16_t length);
 
   void process();
 
@@ -38,7 +38,7 @@ public:
   void setParams(bool on, uint8_t txHang);
 
 private:
-  CSerialRB                        m_buffer;
+  CRingBuffer<uint8_t>                        m_buffer;
   arm_fir_interpolate_instance_q15 m_modFilter;
   q15_t                            m_modState[16U];    // blockSize + phaseLength - 1, 4 + 9 - 1 plus some spare
   uint8_t                          m_poBuffer[1200U];