Add M17 packet mode support.

This commit is contained in:
Jonathan Naylor 2021-01-01 13:17:02 +00:00
parent 9ae4a5376d
commit bada4d9285
3 changed files with 78 additions and 15 deletions

View File

@ -1,5 +1,5 @@
/* /*
* Copyright (C) 2009-2017,2020 by Jonathan Naylor G4KLX * Copyright (C) 2009-2017,2020,2021 by Jonathan Naylor G4KLX
* *
* This program is free software; you can redistribute it and/or modify * 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 * it under the terms of the GNU General Public License as published by
@ -105,8 +105,11 @@ void CM17RX::samples(const q15_t* samples, uint16_t* rssi, uint8_t length)
case M17RXS_HEADER: case M17RXS_HEADER:
processHeader(sample); processHeader(sample);
break; break;
case M17RXS_DATA: case M17RXS_STREAM:
processData(sample); processStream(sample);
break;
case M17RXS_PACKET:
processPacket(sample);
break; break;
default: default:
processNone(sample); processNone(sample);
@ -127,8 +130,9 @@ void CM17RX::processNone(q15_t sample)
{ {
bool ret1 = correlateSync(M17_LINK_SETUP_SYNC_SYMBOLS, M17_LINK_SETUP_SYNC_SYMBOLS_VALUES, M17_LINK_SETUP_SYNC_BYTES); bool ret1 = correlateSync(M17_LINK_SETUP_SYNC_SYMBOLS, M17_LINK_SETUP_SYNC_SYMBOLS_VALUES, M17_LINK_SETUP_SYNC_BYTES);
bool ret2 = correlateSync(M17_STREAM_SYNC_SYMBOLS, M17_STREAM_SYNC_SYMBOLS_VALUES, M17_STREAM_SYNC_BYTES); bool ret2 = correlateSync(M17_STREAM_SYNC_SYMBOLS, M17_STREAM_SYNC_SYMBOLS_VALUES, M17_STREAM_SYNC_BYTES);
bool ret3 = correlateSync(M17_PACKET_SYNC_SYMBOLS, M17_PACKET_SYNC_SYMBOLS_VALUES, M17_PACKET_SYNC_BYTES);
if (ret1 || ret2) { if (ret1 || ret2 || ret3) {
// On the first sync, start the countdown to the state change // On the first sync, start the countdown to the state change
if (m_countdown == 0U) { if (m_countdown == 0U) {
m_rssiAccum = 0U; m_rssiAccum = 0U;
@ -141,7 +145,9 @@ void CM17RX::processNone(q15_t sample)
m_countdown = 5U; m_countdown = 5U;
m_nextState = ret1 ? M17RXS_HEADER : M17RXS_DATA; if (ret1) m_nextState = M17RXS_HEADER;
if (ret2) m_nextState = M17RXS_STREAM;
if (ret3) m_nextState = M17RXS_PACKET;
} }
} }
@ -191,12 +197,12 @@ void CM17RX::processHeader(q15_t sample)
m_lostCount--; m_lostCount--;
frame[0U] = 0x01U; frame[0U] = 0x01U;
writeRSSIHeader(frame); writeRSSIHeader(frame);
m_state = M17RXS_DATA; m_state = M17RXS_NONE;
m_maxCorr = 0; m_maxCorr = 0;
} }
} }
void CM17RX::processData(q15_t sample) void CM17RX::processStream(q15_t sample)
{ {
if (m_minSyncPtr < m_maxSyncPtr) { if (m_minSyncPtr < m_maxSyncPtr) {
if (m_dataPtr >= m_minSyncPtr && m_dataPtr <= m_maxSyncPtr) if (m_dataPtr >= m_minSyncPtr && m_dataPtr <= m_maxSyncPtr)
@ -220,15 +226,15 @@ void CM17RX::processData(q15_t sample)
calculateLevels(m_startPtr, M17_FRAME_LENGTH_SYMBOLS); calculateLevels(m_startPtr, M17_FRAME_LENGTH_SYMBOLS);
DEBUG4("M17RX: data sync found pos/centre/threshold", m_syncPtr, m_centreVal, m_thresholdVal); DEBUG4("M17RX: stream sync found pos/centre/threshold", m_syncPtr, m_centreVal, m_thresholdVal);
uint8_t frame[M17_FRAME_LENGTH_BYTES + 3U]; uint8_t frame[M17_FRAME_LENGTH_BYTES + 3U];
samplesToBits(m_startPtr, M17_FRAME_LENGTH_SYMBOLS, frame, 8U, m_centreVal, m_thresholdVal); samplesToBits(m_startPtr, M17_FRAME_LENGTH_SYMBOLS, frame, 8U, m_centreVal, m_thresholdVal);
// We've not seen a data sync for too long, signal RXLOST and change to RX_NONE // We've not seen a stream sync for too long, signal RXLOST and change to RX_NONE
m_lostCount--; m_lostCount--;
if (m_lostCount == 0U) { if (m_lostCount == 0U) {
DEBUG1("M17RX: sync timed out, lost lock"); DEBUG1("M17RX: stream sync timed out, lost lock");
io.setDecode(false); io.setDecode(false);
io.setADCDetection(false); io.setADCDetection(false);
@ -242,7 +248,62 @@ void CM17RX::processData(q15_t sample)
m_nextState = M17RXS_NONE; m_nextState = M17RXS_NONE;
m_maxCorr = 0; m_maxCorr = 0;
} else { } else {
frame[0U] = m_lostCount == (MAX_SYNC_FRAMES - 1U) ? 0x01U : 0x00U; frame[0U] = 0x00U;
frame[0U] |= m_lostCount == (MAX_SYNC_FRAMES - 1U) ? 0x01U : 0x00U;
writeRSSIData(frame);
m_maxCorr = 0;
}
}
}
void CM17RX::processPacket(q15_t sample)
{
if (m_minSyncPtr < m_maxSyncPtr) {
if (m_dataPtr >= m_minSyncPtr && m_dataPtr <= m_maxSyncPtr)
correlateSync(M17_PACKET_SYNC_SYMBOLS, M17_PACKET_SYNC_SYMBOLS_VALUES, M17_PACKET_SYNC_BYTES);
} else {
if (m_dataPtr >= m_minSyncPtr || m_dataPtr <= m_maxSyncPtr)
correlateSync(M17_PACKET_SYNC_SYMBOLS, M17_PACKET_SYNC_SYMBOLS_VALUES, M17_PACKET_SYNC_BYTES);
}
if (m_dataPtr == m_endPtr) {
// Only update the centre and threshold if they are from a good sync
if (m_lostCount == MAX_SYNC_FRAMES) {
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: packet 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);
// We've not seen a packet sync for too long, signal RXLOST and change to RX_NONE
m_lostCount--;
if (m_lostCount == 0U) {
DEBUG1("M17RX: packet sync timed out, lost lock");
io.setDecode(false);
io.setADCDetection(false);
serial.writeM17Lost();
m_state = M17RXS_NONE;
m_endPtr = NOENDPTR;
m_averagePtr = NOAVEPTR;
m_countdown = 0U;
m_nextState = M17RXS_NONE;
m_maxCorr = 0;
} else {
frame[0U] = 0x02U;
frame[0U] |= m_lostCount == (MAX_SYNC_FRAMES - 1U) ? 0x01U : 0x00U;
writeRSSIData(frame); writeRSSIData(frame);
m_maxCorr = 0; m_maxCorr = 0;
} }

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@ -1,5 +1,5 @@
/* /*
* Copyright (C) 2015,2016,2017,2020 by Jonathan Naylor G4KLX * Copyright (C) 2015,2016,2017,2020,2021 by Jonathan Naylor G4KLX
* *
* This program is free software; you can redistribute it and/or modify * 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 * it under the terms of the GNU General Public License as published by
@ -28,7 +28,8 @@
enum M17RX_STATE { enum M17RX_STATE {
M17RXS_NONE, M17RXS_NONE,
M17RXS_HEADER, M17RXS_HEADER,
M17RXS_DATA M17RXS_STREAM,
M17RXS_PACKET
}; };
class CM17RX { class CM17RX {
@ -64,7 +65,8 @@ private:
void processNone(q15_t sample); void processNone(q15_t sample);
void processHeader(q15_t sample); void processHeader(q15_t sample);
void processData(q15_t sample); void processStream(q15_t sample);
void processPacket(q15_t sample);
bool correlateSync(uint8_t syncSymbols, const int8_t* syncSymbolValues, const uint8_t* syncBytes); bool correlateSync(uint8_t syncSymbols, const int8_t* syncSymbolValues, const uint8_t* syncBytes);
void calculateLevels(uint16_t start, uint16_t count); 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 samplesToBits(uint16_t start, uint16_t count, uint8_t* buffer, uint16_t offset, q15_t centre, q15_t threshold);

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@ -1,5 +1,5 @@
/* /*
* Copyright (C) 2020 by Jonathan Naylor G4KLX * Copyright (C) 2020,2021 by Jonathan Naylor G4KLX
* *
* This program is free software; you can redistribute it and/or modify * 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 * it under the terms of the GNU General Public License as published by