From 57e18e337f766aa931e552c8cb884fb8f0124893 Mon Sep 17 00:00:00 2001 From: Jonathan Naylor Date: Wed, 10 Jun 2020 13:53:18 +0100 Subject: [PATCH] Add the seperate AX25Frame class. --- AX25Demodulator.cpp | 22 +++++++++++- AX25Demodulator.h | 14 ++++---- AX25Frame.cpp | 84 +++++++++++++++++++++++++++++++++++++++++++++ AX25Frame.h | 36 +++++++++++++++++++ AX25RX.cpp | 2 +- 5 files changed, 149 insertions(+), 9 deletions(-) create mode 100644 AX25Frame.cpp create mode 100644 AX25Frame.h diff --git a/AX25Demodulator.cpp b/AX25Demodulator.cpp index 8df7833..e824cc1 100644 --- a/AX25Demodulator.cpp +++ b/AX25Demodulator.cpp @@ -20,16 +20,36 @@ #include "Globals.h" #include "AX25Demodulator.h" +const float DELAY = 0.000448F; +const float SAMPLE_RATE = 24000.0F; + +const uint16_t DELAY_LEN = uint16_t((DELAY / (1.0F / SAMPLE_RATE)) + 0.5F); + CAX25Demodulator::CAX25Demodulator() : +m_delayLine(NULL), +m_delayPos(0U), m_nrziState(false) { + m_delayLine = new bool[2U * DELAY_LEN]; } -bool CAX25Demodulator::process(const q15_t* samples, uint8_t length, AX25Frame& frame) +bool CAX25Demodulator::process(const q15_t* samples, uint8_t length, CAX25Frame& frame) { return false; } +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); diff --git a/AX25Demodulator.h b/AX25Demodulator.h index 16abc7e..550ec8b 100644 --- a/AX25Demodulator.h +++ b/AX25Demodulator.h @@ -21,21 +21,21 @@ #include "Config.h" -struct AX25Frame { - uint8_t m_data[300U]; - uint16_t m_length; - uint16_t m_fcs; -}; +#include "AX25Frame.h" + class CAX25Demodulator { public: CAX25Demodulator(); - bool process(const q15_t* samples, uint8_t length, AX25Frame& frame); + bool process(const q15_t* samples, uint8_t length, CAX25Frame& frame); private: - bool m_nrziState; + bool* m_delayLine; + uint16_t m_delayPos; + bool m_nrziState; + bool delay(bool b); bool NRZI(bool b); }; diff --git a/AX25Frame.cpp b/AX25Frame.cpp new file mode 100644 index 0000000..2540cb3 --- /dev/null +++ b/AX25Frame.cpp @@ -0,0 +1,84 @@ +/* + * 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[] = { + 0x0000U, 0x1189U, 0x2312U, 0x329bU, 0x4624U, 0x57adU, 0x6536U, 0x74bfU, + 0x8c48U, 0x9dc1U, 0xaf5aU, 0xbed3U, 0xca6cU, 0xdbe5U, 0xe97eU, 0xf8f7U, + 0x1081U, 0x0108U, 0x3393U, 0x221aU, 0x56a5U, 0x472cU, 0x75b7U, 0x643eU, + 0x9cc9U, 0x8d40U, 0xbfdbU, 0xae52U, 0xdaedU, 0xcb64U, 0xf9ffU, 0xe876U, + 0x2102U, 0x308bU, 0x0210U, 0x1399U, 0x6726U, 0x76afU, 0x4434U, 0x55bdU, + 0xad4aU, 0xbcc3U, 0x8e58U, 0x9fd1U, 0xeb6eU, 0xfae7U, 0xc87cU, 0xd9f5U, + 0x3183U, 0x200aU, 0x1291U, 0x0318U, 0x77a7U, 0x662eU, 0x54b5U, 0x453cU, + 0xbdcbU, 0xac42U, 0x9ed9U, 0x8f50U, 0xfbefU, 0xea66U, 0xd8fdU, 0xc974U, + 0x4204U, 0x538dU, 0x6116U, 0x709fU, 0x0420U, 0x15a9U, 0x2732U, 0x36bbU, + 0xce4cU, 0xdfc5U, 0xed5eU, 0xfcd7U, 0x8868U, 0x99e1U, 0xab7aU, 0xbaf3U, + 0x5285U, 0x430cU, 0x7197U, 0x601eU, 0x14a1U, 0x0528U, 0x37b3U, 0x263aU, + 0xdecdU, 0xcf44U, 0xfddfU, 0xec56U, 0x98e9U, 0x8960U, 0xbbfbU, 0xaa72U, + 0x6306U, 0x728fU, 0x4014U, 0x519dU, 0x2522U, 0x34abU, 0x0630U, 0x17b9U, + 0xef4eU, 0xfec7U, 0xcc5cU, 0xddd5U, 0xa96aU, 0xb8e3U, 0x8a78U, 0x9bf1U, + 0x7387U, 0x620eU, 0x5095U, 0x411cU, 0x35a3U, 0x242aU, 0x16b1U, 0x0738U, + 0xffcfU, 0xee46U, 0xdcddU, 0xcd54U, 0xb9ebU, 0xa862U, 0x9af9U, 0x8b70U, + 0x8408U, 0x9581U, 0xa71aU, 0xb693U, 0xc22cU, 0xd3a5U, 0xe13eU, 0xf0b7U, + 0x0840U, 0x19c9U, 0x2b52U, 0x3adbU, 0x4e64U, 0x5fedU, 0x6d76U, 0x7cffU, + 0x9489U, 0x8500U, 0xb79bU, 0xa612U, 0xd2adU, 0xc324U, 0xf1bfU, 0xe036U, + 0x18c1U, 0x0948U, 0x3bd3U, 0x2a5aU, 0x5ee5U, 0x4f6cU, 0x7df7U, 0x6c7eU, + 0xa50aU, 0xb483U, 0x8618U, 0x9791U, 0xe32eU, 0xf2a7U, 0xc03cU, 0xd1b5U, + 0x2942U, 0x38cbU, 0x0a50U, 0x1bd9U, 0x6f66U, 0x7eefU, 0x4c74U, 0x5dfdU, + 0xb58bU, 0xa402U, 0x9699U, 0x8710U, 0xf3afU, 0xe226U, 0xd0bdU, 0xc134U, + 0x39c3U, 0x284aU, 0x1ad1U, 0x0b58U, 0x7fe7U, 0x6e6eU, 0x5cf5U, 0x4d7cU, + 0xc60cU, 0xd785U, 0xe51eU, 0xf497U, 0x8028U, 0x91a1U, 0xa33aU, 0xb2b3U, + 0x4a44U, 0x5bcdU, 0x6956U, 0x78dfU, 0x0c60U, 0x1de9U, 0x2f72U, 0x3efbU, + 0xd68dU, 0xc704U, 0xf59fU, 0xe416U, 0x90a9U, 0x8120U, 0xb3bbU, 0xa232U, + 0x5ac5U, 0x4b4cU, 0x79d7U, 0x685eU, 0x1ce1U, 0x0d68U, 0x3ff3U, 0x2e7aU, + 0xe70eU, 0xf687U, 0xc41cU, 0xd595U, 0xa12aU, 0xb0a3U, 0x8238U, 0x93b1U, + 0x6b46U, 0x7acfU, 0x4854U, 0x59ddU, 0x2d62U, 0x3cebU, 0x0e70U, 0x1ff9U, + 0xf78fU, 0xe606U, 0xd49dU, 0xc514U, 0xb1abU, 0xa022U, 0x92b9U, 0x8330U, + 0x7bc7U, 0x6a4eU, 0x58d5U, 0x495cU, 0x3de3U, 0x2c6aU, 0x1ef1U, 0x0f78U}; + +CAX25Frame::CAX25Frame() : +m_data(), +m_length(0U), +m_fcs(0U) +{ +} + +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; + } +} + diff --git a/AX25Frame.h b/AX25Frame.h new file mode 100644 index 0000000..30e08f7 --- /dev/null +++ b/AX25Frame.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(AX25Frame_H) +#define AX25Frame_H + +#include "Config.h" + +class CAX25Frame { +public: + CAX25Frame(); + + bool checkCRC(); + + uint8_t m_data[300U]; + uint16_t m_length; + uint16_t m_fcs; +}; + +#endif + diff --git a/AX25RX.cpp b/AX25RX.cpp index 2fea46e..538e014 100644 --- a/AX25RX.cpp +++ b/AX25RX.cpp @@ -30,7 +30,7 @@ m_lastFCS(0U) void CAX25RX::samples(const q15_t* samples, uint8_t length) { - AX25Frame frame; + CAX25Frame frame; bool ret = m_demod1.process(samples, length, frame); if (ret) {