From 6d0335b357183ef38d9320954edde8e144e16365 Mon Sep 17 00:00:00 2001 From: Jonathan Naylor Date: Thu, 26 Nov 2020 10:03:54 +0000 Subject: [PATCH] Update for latest M17 specification. --- M17Defines.h | 25 ++++++++++----- M17RX.cpp | 85 ++++++++++++++++++++++++++++++++++++++++++++------ M17RX.h | 6 +++- SerialPort.cpp | 42 +++++++++++++++++++++++-- SerialPort.h | 1 + Version.h | 2 +- 6 files changed, 140 insertions(+), 21 deletions(-) diff --git a/M17Defines.h b/M17Defines.h index 4947341..f98214b 100644 --- a/M17Defines.h +++ b/M17Defines.h @@ -30,18 +30,29 @@ const unsigned int M17_SYNC_LENGTH_BITS = 16U; const unsigned int M17_SYNC_LENGTH_SYMBOLS = M17_SYNC_LENGTH_BITS / 2U; const unsigned int M17_SYNC_LENGTH_SAMPLES = M17_SYNC_LENGTH_SYMBOLS * M17_RADIO_SYMBOL_LENGTH; -const uint8_t M17_SYNC_BYTES[] = {0x32U, 0x43U}; +const uint8_t M17_HEADER_SYNC_BYTES[] = {0x5DU, 0xDDU}; +const uint8_t M17_DATA_SYNC_BYTES[] = {0xDDU, 0xDDU}; + const uint8_t M17_SYNC_BYTES_LENGTH = 2U; -const uint16_t M17_SYNC_BITS = 0x3243U; +const uint16_t M17_HEADER_SYNC_BITS = 0x5DDDU; +const uint16_t M17_DAYA_SYNC_BITS = 0xDDDDU; -// 3 2 4 3 -// 00 11 00 10 01 00 00 11 -// +1 -3 +1 -1 +3 +1 +1 -3 +// 5 D D D +// 01 01 11 01 11 01 11 01 +// +3 +3 -3 +3 -3 +3 -3 +3 -const int8_t M17_SYNC_SYMBOLS_VALUES[] = {+1, -3, +1, -1, +3, +1, +1, -3}; +const int8_t M17_HEADER_SYNC_SYMBOLS_VALUES[] = {+3, +3, -3, +3, -3, +3, -3, +3}; -const uint8_t M17_SYNC_SYMBOLS = 0xAEU; +const uint8_t M17_HEADER_SYNC_SYMBOLS = 0xD5U; + +// D D D D +// 11 01 11 01 11 01 11 01 +// -3 +3 -3 +3 -3 +3 -3 +3 + +const int8_t M17_DATA_SYNC_SYMBOLS_VALUES[] = {-3, +3, -3, +3, -3, +3, -3, +3}; + +const uint8_t M17_DATA_SYNC_SYMBOLS = 0x55U; #endif diff --git a/M17RX.cpp b/M17RX.cpp index 25f097c..18a0a97 100644 --- a/M17RX.cpp +++ b/M17RX.cpp @@ -55,6 +55,7 @@ m_maxSyncPtr(NOENDPTR), m_maxCorr(0), m_lostCount(0U), m_countdown(0U), +m_nextState(M17RXS_NONE), m_centre(), m_centreVal(0), m_threshold(), @@ -81,6 +82,7 @@ void CM17RX::reset() m_thresholdVal = 0; m_lostCount = 0U; m_countdown = 0U; + m_nextState = M17RXS_NONE; m_rssiAccum = 0U; m_rssiCount = 0U; } @@ -100,6 +102,9 @@ void CM17RX::samples(const q15_t* samples, uint16_t* rssi, uint8_t length) m_buffer[m_dataPtr] = sample; switch (m_state) { + case M17RXS_HEADER: + processHeader(sample); + break; case M17RXS_DATA: processData(sample); break; @@ -120,8 +125,10 @@ void CM17RX::samples(const q15_t* samples, uint16_t* rssi, uint8_t length) void CM17RX::processNone(q15_t sample) { - bool ret = correlateSync(); - if (ret) { + bool ret1 = correlateSync(M17_HEADER_SYNC_SYMBOLS, M17_HEADER_SYNC_SYMBOLS_VALUES, M17_HEADER_SYNC_BYTES); + bool ret2 = correlateSync(M17_DATA_SYNC_SYMBOLS, M17_DATA_SYNC_SYMBOLS_VALUES, M17_DATA_SYNC_BYTES); + + if (ret1 || ret2) { // On the first sync, start the countdown to the state change if (m_countdown == 0U) { m_rssiAccum = 0U; @@ -133,6 +140,8 @@ void CM17RX::processNone(q15_t sample) m_averagePtr = NOAVEPTR; m_countdown = 5U; + + m_nextState = ret1 ? M17RXS_HEADER : M17RXS_DATA; } } @@ -148,19 +157,53 @@ void CM17RX::processNone(q15_t sample) if (m_maxSyncPtr >= M17_FRAME_LENGTH_SAMPLES) m_maxSyncPtr -= M17_FRAME_LENGTH_SAMPLES; - m_state = M17RXS_DATA; + m_state = m_nextState; m_countdown = 0U; } } +void CM17RX::processHeader(q15_t sample) +{ + if (m_minSyncPtr < m_maxSyncPtr) { + if (m_dataPtr >= m_minSyncPtr && m_dataPtr <= m_maxSyncPtr) + correlateSync(M17_HEADER_SYNC_SYMBOLS, M17_HEADER_SYNC_SYMBOLS_VALUES, M17_HEADER_SYNC_BYTES); + } else { + if (m_dataPtr >= m_minSyncPtr || m_dataPtr <= m_maxSyncPtr) + correlateSync(M17_HEADER_SYNC_SYMBOLS, M17_HEADER_SYNC_SYMBOLS_VALUES, M17_HEADER_SYNC_BYTES); + } + + if (m_dataPtr == m_endPtr) { + m_minSyncPtr = m_syncPtr + M17_FRAME_LENGTH_SAMPLES - 1U; + if (m_minSyncPtr >= M17_FRAME_LENGTH_SAMPLES) + m_minSyncPtr -= M17_FRAME_LENGTH_SAMPLES; + + m_maxSyncPtr = m_syncPtr + 1U; + if (m_maxSyncPtr >= M17_FRAME_LENGTH_SAMPLES) + m_maxSyncPtr -= M17_FRAME_LENGTH_SAMPLES; + + calculateLevels(m_startPtr, M17_FRAME_LENGTH_SYMBOLS); + + DEBUG4("M17RX: header sync found pos/centre/threshold", m_syncPtr, m_centreVal, m_thresholdVal); + + uint8_t frame[M17_FRAME_LENGTH_BYTES + 3U]; + samplesToBits(m_startPtr, M17_FRAME_LENGTH_SYMBOLS, frame, 8U, m_centreVal, m_thresholdVal); + + m_lostCount--; + frame[0U] = 0x01U; + writeRSSIHeader(frame); + m_state = M17RXS_DATA; + m_maxCorr = 0; + } +} + void CM17RX::processData(q15_t sample) { if (m_minSyncPtr < m_maxSyncPtr) { if (m_dataPtr >= m_minSyncPtr && m_dataPtr <= m_maxSyncPtr) - correlateSync(); + correlateSync(M17_DATA_SYNC_SYMBOLS, M17_DATA_SYNC_SYMBOLS_VALUES, M17_DATA_SYNC_BYTES); } else { if (m_dataPtr >= m_minSyncPtr || m_dataPtr <= m_maxSyncPtr) - correlateSync(); + correlateSync(M17_DATA_SYNC_SYMBOLS, M17_DATA_SYNC_SYMBOLS_VALUES, M17_DATA_SYNC_BYTES); } if (m_dataPtr == m_endPtr) { @@ -177,7 +220,7 @@ void CM17RX::processData(q15_t sample) calculateLevels(m_startPtr, M17_FRAME_LENGTH_SYMBOLS); - DEBUG4("M17RX: sync found pos/centre/threshold", m_syncPtr, m_centreVal, m_thresholdVal); + DEBUG4("M17RX: data sync found pos/centre/threshold", m_syncPtr, m_centreVal, m_thresholdVal); uint8_t frame[M17_FRAME_LENGTH_BYTES + 3U]; samplesToBits(m_startPtr, M17_FRAME_LENGTH_SYMBOLS, frame, 8U, m_centreVal, m_thresholdVal); @@ -196,6 +239,7 @@ void CM17RX::processData(q15_t sample) m_endPtr = NOENDPTR; m_averagePtr = NOAVEPTR; m_countdown = 0U; + m_nextState = M17RXS_NONE; m_maxCorr = 0; } else { frame[0U] = m_lostCount == (MAX_SYNC_FRAMES - 1U) ? 0x01U : 0x00U; @@ -205,9 +249,9 @@ void CM17RX::processData(q15_t sample) } } -bool CM17RX::correlateSync() +bool CM17RX::correlateSync(uint8_t syncSymbols, const int8_t* syncSymbolValues, const uint8_t* syncBytes) { - if (countBits8(m_bitBuffer[m_bitPtr] ^ M17_SYNC_SYMBOLS) <= MAX_SYNC_SYMBOLS_ERRS) { + if (countBits8(m_bitBuffer[m_bitPtr] ^ syncSymbols) <= MAX_SYNC_SYMBOLS_ERRS) { uint16_t ptr = m_dataPtr + M17_FRAME_LENGTH_SAMPLES - M17_SYNC_LENGTH_SAMPLES + M17_RADIO_SYMBOL_LENGTH; if (ptr >= M17_FRAME_LENGTH_SAMPLES) ptr -= M17_FRAME_LENGTH_SAMPLES; @@ -224,7 +268,7 @@ bool CM17RX::correlateSync() if (val < min) min = val; - switch (M17_SYNC_SYMBOLS_VALUES[i]) { + switch (syncSymbolValues[i]) { case +3: corr -= (val + val + val); break; @@ -267,7 +311,7 @@ bool CM17RX::correlateSync() uint8_t errs = 0U; for (uint8_t i = 0U; i < M17_SYNC_BYTES_LENGTH; i++) - errs += countBits8(sync[i] ^ M17_SYNC_BYTES[i]); + errs += countBits8(sync[i] ^ syncBytes[i]); if (errs <= maxErrs) { m_maxCorr = corr; @@ -385,6 +429,27 @@ void CM17RX::samplesToBits(uint16_t start, uint16_t count, uint8_t* buffer, uint } } +void CM17RX::writeRSSIHeader(uint8_t* data) +{ +#if defined(SEND_RSSI_DATA) + if (m_rssiCount > 0U) { + uint16_t rssi = m_rssiAccum / m_rssiCount; + + data[121U] = (rssi >> 8) & 0xFFU; + data[122U] = (rssi >> 0) & 0xFFU; + + serial.writeM17Header(data, M17_FRAME_LENGTH_BYTES + 3U); + } else { + serial.writeM17Header(data, M17_FRAME_LENGTH_BYTES + 1U); + } +#else + serial.writeM17Header(data, M17_FRAME_LENGTH_BYTES + 1U); +#endif + + m_rssiAccum = 0U; + m_rssiCount = 0U; +} + void CM17RX::writeRSSIData(uint8_t* data) { #if defined(SEND_RSSI_DATA) diff --git a/M17RX.h b/M17RX.h index cc7cb1c..5700d54 100644 --- a/M17RX.h +++ b/M17RX.h @@ -27,6 +27,7 @@ enum M17RX_STATE { M17RXS_NONE, + M17RXS_HEADER, M17RXS_DATA }; @@ -52,6 +53,7 @@ private: q31_t m_maxCorr; uint16_t m_lostCount; uint8_t m_countdown; + M17RX_STATE m_nextState; q15_t m_centre[16U]; q15_t m_centreVal; q15_t m_threshold[16U]; @@ -61,10 +63,12 @@ private: uint16_t m_rssiCount; void processNone(q15_t sample); + void processHeader(q15_t sample); void processData(q15_t sample); - bool correlateSync(); + bool correlateSync(uint8_t syncSymbols, const int8_t* syncSymbolValues, const uint8_t* syncBytes); void calculateLevels(uint16_t start, uint16_t count); void samplesToBits(uint16_t start, uint16_t count, uint8_t* buffer, uint16_t offset, q15_t centre, q15_t threshold); + void writeRSSIHeader(uint8_t* data); void writeRSSIData(uint8_t* data); }; diff --git a/SerialPort.cpp b/SerialPort.cpp index 5e8dc05..9ce0892 100644 --- a/SerialPort.cpp +++ b/SerialPort.cpp @@ -63,8 +63,9 @@ const uint8_t MMDVM_P25_LOST = 0x32U; const uint8_t MMDVM_NXDN_DATA = 0x40U; const uint8_t MMDVM_NXDN_LOST = 0x41U; -const uint8_t MMDVM_M17_DATA = 0x45U; -const uint8_t MMDVM_M17_LOST = 0x46U; +const uint8_t MMDVM_M17_HEADER = 0x45U; +const uint8_t MMDVM_M17_DATA = 0x46U; +const uint8_t MMDVM_M17_LOST = 0x47U; const uint8_t MMDVM_POCSAG_DATA = 0x50U; @@ -1257,6 +1258,20 @@ void CSerialPort::processMessage(uint8_t type, const uint8_t* buffer, uint16_t l #endif #if defined(MODE_M17) + case MMDVM_M17_HEADER: + if (m_m17Enable) { + if (m_modemState == STATE_IDLE || m_modemState == STATE_M17) + err = m17TX.writeData(buffer, length); + } + if (err == 0U) { + if (m_modemState == STATE_IDLE) + setMode(STATE_M17); + } else { + DEBUG2("Received invalid M17 header", err); + sendNAK(err); + } + break; + case MMDVM_M17_DATA: if (m_m17Enable) { if (m_modemState == STATE_IDLE || m_modemState == STATE_M17) @@ -1621,6 +1636,29 @@ void CSerialPort::writeNXDNLost() #endif #if defined(MODE_M17) +void CSerialPort::writeM17Header(const uint8_t* data, uint8_t length) +{ + if (m_modemState != STATE_M17 && m_modemState != STATE_IDLE) + return; + + if (!m_m17Enable) + return; + + uint8_t reply[130U]; + + reply[0U] = MMDVM_FRAME_START; + reply[1U] = 0U; + reply[2U] = MMDVM_M17_HEADER; + + uint8_t count = 3U; + for (uint8_t i = 0U; i < length; i++, count++) + reply[count] = data[i]; + + reply[1U] = count; + + writeInt(1U, reply, count); +} + void CSerialPort::writeM17Data(const uint8_t* data, uint8_t length) { if (m_modemState != STATE_M17 && m_modemState != STATE_IDLE) diff --git a/SerialPort.h b/SerialPort.h index 2a6a8e5..3302a8d 100644 --- a/SerialPort.h +++ b/SerialPort.h @@ -65,6 +65,7 @@ public: #endif #if defined(MODE_M17) + void writeM17Header(const uint8_t* data, uint8_t length); void writeM17Data(const uint8_t* data, uint8_t length); void writeM17Lost(); #endif diff --git a/Version.h b/Version.h index 0972132..c3d6469 100644 --- a/Version.h +++ b/Version.h @@ -19,7 +19,7 @@ #if !defined(VERSION_H) #define VERSION_H -#define VERSION "20201120" +#define VERSION "20201126" #endif