Fix and simplify the M17 receiver.

M17RX.cpp

@@ -54,13 +54,9 @@ void CM17RX::databit(bool bit)
 {
  switch (m_state) {
  case M17RXS_LINK_SETUP:
- processLinkSetup(bit);
- break;
  case M17RXS_STREAM:
- processStream(bit);
- break;
  case M17RXS_PACKET:
- processPacket(bit);
+ processData(bit);
  break;
  default:
  processNone(bit);
@@ -114,7 +110,7 @@ void CM17RX::processNone(bool bit)
  }
 }
 
-void CM17RX::processLinkSetup(bool bit)
+void CM17RX::processData(bool bit)
 {
  m_bitBuffer <<= 1;
  if (bit)
@@ -126,30 +122,16 @@ void CM17RX::processLinkSetup(bool bit)
  if (m_bufferPtr > M17_FRAME_LENGTH_BITS)
  reset();
 
- // Send a data frame to the host if the required number of bits have been received
- if (m_bufferPtr == M17_FRAME_LENGTH_BITS) {
- m_lostCount--;
-
- // Write data to host
- m_outBuffer[0U] = 0x01U;
- writeRSSIHeader(m_outBuffer);
-
- // Start the next frame, but we don't know the type
- reset();
+ // Only search for a link setup sync in the right place +-2 symbols
+ if (m_bufferPtr >= (M17_SYNC_LENGTH_BITS - 2U) && m_bufferPtr <= (M17_SYNC_LENGTH_BITS + 2U)) {
+ // Fuzzy matching of the stream sync bit sequence
+ if (countBits16(m_bitBuffer ^ M17_LINK_SETUP_SYNC_BITS) <= MAX_SYNC_BIT_RUN_ERRS) {
+ DEBUG2("M17RX: found link setup sync, pos", m_bufferPtr - M17_SYNC_LENGTH_BITS);
+ m_lostCount = MAX_SYNC_FRAMES;
+ m_bufferPtr = M17_SYNC_LENGTH_BITS;
+ m_state = M17RXS_LINK_SETUP;
+ }
  }
-}
-
-void CM17RX::processStream(bool bit)
-{
- m_bitBuffer <<= 1;
- if (bit)
- m_bitBuffer |= 0x01U;
-
- WRITE_BIT1(m_buffer, m_bufferPtr, bit);
-
- m_bufferPtr++;
- if (m_bufferPtr > M17_FRAME_LENGTH_BITS)
- reset();
 
  // Only search for a stream sync in the right place +-2 symbols
  if (m_bufferPtr >= (M17_SYNC_LENGTH_BITS - 2U) && m_bufferPtr <= (M17_SYNC_LENGTH_BITS + 2U)) {
@@ -158,67 +140,46 @@ void CM17RX::processStream(bool bit)
  DEBUG2("M17RX: found stream sync, pos", m_bufferPtr - M17_SYNC_LENGTH_BITS);
  m_lostCount = MAX_SYNC_FRAMES;
  m_bufferPtr = M17_SYNC_LENGTH_BITS;
+ m_state = M17RXS_STREAM;
  }
  }
 
- // Send a stream frame to the host if the required number of bits have been received
- if (m_bufferPtr == M17_FRAME_LENGTH_BITS) {
- // We've not seen a stream sync for too long, signal RXLOST and change to RX_NONE
- m_lostCount--;
- if (m_lostCount == 0U) {
- DEBUG1("M17RX: stream sync timed out, lost lock");
- io.setDecode(false);
- serial.writeM17Lost();
- reset();
- } else {
- // Write data to host
- m_outBuffer[0U] = 0x00U; // Stream data
- m_outBuffer[0U] |= m_lostCount == (MAX_SYNC_FRAMES - 1U) ? 0x01U : 0x00U;
- writeRSSIData(m_outBuffer);
-
- // Start the next frame
- ::memset(m_outBuffer, 0x00U, M17_FRAME_LENGTH_BYTES + 3U);
- m_bufferPtr = 0U;
- }
- }
-}
-
-void CM17RX::processPacket(bool bit)
-{
- m_bitBuffer <<= 1;
- if (bit)
- m_bitBuffer |= 0x01U;
-
- WRITE_BIT1(m_buffer, m_bufferPtr, bit);
-
- m_bufferPtr++;
- if (m_bufferPtr > M17_FRAME_LENGTH_BITS)
- reset();
-
  // Only search for a packet sync in the right place +-2 symbols
  if (m_bufferPtr >= (M17_SYNC_LENGTH_BITS - 2U) && m_bufferPtr <= (M17_SYNC_LENGTH_BITS + 2U)) {
- // Fuzzy matching of the packet sync bit sequence
- if (countBits16(m_bitBuffer ^ M17_PACKET_SYNC_BITS) <= MAX_SYNC_BIT_RUN_ERRS) {
+ // Fuzzy matching of the stream sync bit sequence
+ if (countBits16(m_bitBuffer ^ M17_STREAM_SYNC_BITS) <= MAX_SYNC_BIT_RUN_ERRS) {
  DEBUG2("M17RX: found packet sync, pos", m_bufferPtr - M17_SYNC_LENGTH_BITS);
  m_lostCount = MAX_SYNC_FRAMES;
  m_bufferPtr = M17_SYNC_LENGTH_BITS;
+ m_state = M17RXS_PACKET;
  }
  }
 
- // Send a packet frame to the host if the required number of bits have been received
+ // Send a frame to the host if the required number of bits have been received
  if (m_bufferPtr == M17_FRAME_LENGTH_BITS) {
- // We've not seen a packet sync for too long, signal RXLOST and change to RX_NONE
+ // We've not seen a 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");
+ DEBUG1("M17RX: sync timed out, lost lock");
  io.setDecode(false);
  serial.writeM17Lost();
  reset();
  } else {
  // Write data to host
- m_outBuffer[0U] = 0x02U; // Packet data
+ m_outBuffer[0U] = 0x00U; // Stream data
  m_outBuffer[0U] |= m_lostCount == (MAX_SYNC_FRAMES - 1U) ? 0x01U : 0x00U;
- writeRSSIData(m_outBuffer);
+
+ switch (m_state) {
+ case M17RXS_LINK_SETUP:
+ writeRSSILinkSetup(m_outBuffer);
+ break;
+ case M17RXS_STREAM:
+ writeRSSIStream(m_outBuffer);
+ break;
+ default:
+ writeRSSIPacket(m_outBuffer);
+ break;
+ }
 
  // Start the next frame
  ::memset(m_outBuffer, 0x00U, M17_FRAME_LENGTH_BYTES + 3U);
@@ -227,30 +188,45 @@ void CM17RX::processPacket(bool bit)
  }
 }
 
-void CM17RX::writeRSSIHeader(uint8_t* data)
+void CM17RX::writeRSSILinkSetup(uint8_t* data)
 {
 #if defined(SEND_RSSI_DATA)
  uint16_t rssi = io.readRSSI();
 
  data[49U] = (rssi >> 8) & 0xFFU;
  data[50U] = (rssi >> 0) & 0xFFU;
 
- serial.writeM17Header(data, M17_FRAME_LENGTH_BYTES + 3U);
+ serial.writeM17LinkSetup(data, M17_FRAME_LENGTH_BYTES + 3U);
 #else
- serial.writeM17Header(data, M17_FRAME_LENGTH_BYTES + 1U);
+ serial.writeM17LinkSetup(data, M17_FRAME_LENGTH_BYTES + 1U);
 #endif
 }
 
-void CM17RX::writeRSSIData(uint8_t* data)
+void CM17RX::writeRSSIStream(uint8_t* data)
 {
 #if defined(SEND_RSSI_DATA)
  uint16_t rssi = io.readRSSI();
 
  data[49U] = (rssi >> 8) & 0xFFU;
  data[50U] = (rssi >> 0) & 0xFFU;
 
- serial.writeM17Data(data, M17_FRAME_LENGTH_BYTES + 3U);
+ serial.writeM17Stream(data, M17_FRAME_LENGTH_BYTES + 3U);
 #else
- serial.writeM17Data(data, M17_FRAME_LENGTH_BYTES + 1U);
+ serial.writeM17Stream(data, M17_FRAME_LENGTH_BYTES + 1U);
 #endif
 }
+
+void CM17RX::writeRSSIPacket(uint8_t* data)
+{
+#if defined(SEND_RSSI_DATA)
+ uint16_t rssi = io.readRSSI();
+
+ data[49U] = (rssi >> 8) & 0xFFU;
+ data[50U] = (rssi >> 0) & 0xFFU;
+
+ serial.writeM17Packet(data, M17_FRAME_LENGTH_BYTES + 3U);
+#else
+ serial.writeM17Packet(data, M17_FRAME_LENGTH_BYTES + 1U);
+#endif
+}
+

M17RX.h

@@ -46,11 +46,11 @@ class CM17RX {
  uint16_t m_lostCount;
 
  void processNone(bool bit);
- void processLinkSetup(bool bit);
- void processStream(bool bit);
- void processPacket(bool bit);
- void writeRSSIHeader(uint8_t* data);
- void writeRSSIData(uint8_t* data);
+ void processData(bool bit);
+ void writeRSSILinkSetup(uint8_t* data);
+ void writeRSSIStream(uint8_t* data);
+ void writeRSSIPacket(uint8_t* data);
 };
 
 #endif
+

SerialPort.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013,2015,2016,2018,2020 by Jonathan Naylor G4KLX
+ * Copyright (C) 2013,2015,2016,2018,2020,2021 by Jonathan Naylor G4KLX
  * Copyright (C) 2016 by Colin Durbridge G4EML
  * Copyright (C) 2016,2017,2018,2019 by Andy Uribe CA6JAU
  * Copyright (C) 2019 by Florian Wolters DF2ET
@@ -60,9 +60,10 @@ 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_HEADER = 0x45U;
-const uint8_t MMDVM_M17_DATA = 0x46U;
-const uint8_t MMDVM_M17_LOST = 0x47U;
+const uint8_t MMDVM_M17_LINK_SETUP = 0x45U;
+const uint8_t MMDVM_M17_STREAM = 0x46U;
+const uint8_t MMDVM_M17_PACKET = 0x47U;
+const uint8_t MMDVM_M17_LOST = 0x48U;
 
 const uint8_t MMDVM_POCSAG_DATA = 0x50U;
 
@@ -865,7 +866,7 @@ void CSerialPort::process()
  }
  break;
 
- case MMDVM_M17_HEADER:
+ case MMDVM_M17_LINK_SETUP:
  if (m_m17Enable) {
  if (m_modemState == STATE_IDLE || m_modemState == STATE_M17)
  err = m17TX.writeData(m_buffer + 3U, m_len - 3U);
@@ -874,12 +875,12 @@ void CSerialPort::process()
  if (m_modemState == STATE_IDLE)
  setMode(STATE_M17);
  } else {
- DEBUG2("Received invalid M17 header", err);
+ DEBUG2("Received invalid M17 link setup data", err);
  sendNAK(err);
  }
  break;
 
- case MMDVM_M17_DATA:
+ case MMDVM_M17_STREAM:
  if (m_m17Enable) {
  if (m_modemState == STATE_IDLE || m_modemState == STATE_M17)
  err = m17TX.writeData(m_buffer + 3U, m_len - 3U);
@@ -888,7 +889,21 @@ void CSerialPort::process()
  if (m_modemState == STATE_IDLE)
  setMode(STATE_M17);
  } else {
- DEBUG2("Received invalid M17 data", err);
+ DEBUG2("Received invalid M17 stream data", err);
+ sendNAK(err);
+ }
+ break;
+
+ case MMDVM_M17_PACKET:
+ if (m_m17Enable) {
+ if (m_modemState == STATE_IDLE || m_modemState == STATE_M17)
+ err = m17TX.writeData(m_buffer + 3U, m_len - 3U);
+ }
+ if (err == 0U) {
+ if (m_modemState == STATE_IDLE)
+ setMode(STATE_M17);
+ } else {
+ DEBUG2("Received invalid M17 packet data", err);
  sendNAK(err);
  }
  break;
@@ -1248,7 +1263,30 @@ void CSerialPort::writeNXDNLost()
  writeInt(1U, reply, 3);
 }
 
-void CSerialPort::writeM17Header(const uint8_t* data, uint8_t length)
+void CSerialPort::writeM17LinkSetup(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_LINK_SETUP;
+
+ 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::writeM17Stream(const uint8_t* data, uint8_t length)
 {
  if (m_modemState != STATE_M17 && m_modemState != STATE_IDLE)
  return;
@@ -1260,7 +1298,7 @@ void CSerialPort::writeM17Header(const uint8_t* data, uint8_t length)
 
  reply[0U] = MMDVM_FRAME_START;
  reply[1U] = 0U;
- reply[2U] = MMDVM_M17_HEADER;
+ reply[2U] = MMDVM_M17_STREAM;
 
  uint8_t count = 3U;
  for (uint8_t i = 0U; i < length; i++, count++)
@@ -1271,7 +1309,7 @@ void CSerialPort::writeM17Header(const uint8_t* data, uint8_t length)
  writeInt(1U, reply, count);
 }
 
-void CSerialPort::writeM17Data(const uint8_t* data, uint8_t length)
+void CSerialPort::writeM17Packet(const uint8_t* data, uint8_t length)
 {
  if (m_modemState != STATE_M17 && m_modemState != STATE_IDLE)
  return;
@@ -1283,7 +1321,7 @@ void CSerialPort::writeM17Data(const uint8_t* data, uint8_t length)
 
  reply[0U] = MMDVM_FRAME_START;
  reply[1U] = 0U;
- reply[2U] = MMDVM_M17_DATA;
+ reply[2U] = MMDVM_M17_PACKET;
 
  uint8_t count = 3U;
  for (uint8_t i = 0U; i < length; i++, count++)

SerialPort.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2015,2016,2018,2020 by Jonathan Naylor G4KLX
+ * Copyright (C) 2015,2016,2018,2020,2021 by Jonathan Naylor G4KLX
  * Copyright (C) 2018 by Andy Uribe CA6JAU
  *
  * This program is free software; you can redistribute it and/or modify
@@ -52,8 +52,9 @@ class CSerialPort {
  void writeNXDNData(const uint8_t* data, uint8_t length);
  void writeNXDNLost();
 
- void writeM17Header(const uint8_t* data, uint8_t length);
- void writeM17Data(const uint8_t* data, uint8_t length);
+ void writeM17LinkSetup(const uint8_t* data, uint8_t length);
+ void writeM17Stream(const uint8_t* data, uint8_t length);
+ void writeM17Packet(const uint8_t* data, uint8_t length);
  void writeM17Lost();
 
 #if defined(SEND_RSSI_DATA)

version.h

@@ -25,7 +25,7 @@
 #define VER_MAJOR "1"
 #define VER_MINOR "5"
 #define VER_REV "2"
-#define VERSION_DATE "20210102"
+#define VERSION_DATE "20210314"
 
 #if defined(ZUMSPOT_ADF7021)
 #define BOARD_INFO "ZUMspot"