Add support for the new EOF sync pattern.

M17Defines.h

@@ -25,14 +25,17 @@ const unsigned int M17_FRAME_LENGTH_BITS    = 384U;
 const unsigned int M17_FRAME_LENGTH_BYTES   = M17_FRAME_LENGTH_BITS / 8U;
 
 const unsigned int M17_SYNC_LENGTH_BITS    = 16U;
+const unsigned int M17_SYNC_LENGTH_BYTES   = M17_SYNC_LENGTH_BITS / 8U;
 
 const uint8_t M17_LINK_SETUP_SYNC_BYTES[] = {0x55U, 0xF7U};
 const uint8_t M17_STREAM_SYNC_BYTES[]     = {0xFFU, 0x5DU};
+const uint8_t M17_EOF_SYNC_BYTES[]        = {0x55U, 0x5DU};
 
 const uint8_t M17_SYNC_BYTES_LENGTH = 2U;
 
 const uint16_t M17_LINK_SETUP_SYNC_BITS = 0x55F7U;
 const uint16_t M17_STREAM_SYNC_BITS     = 0xFF5DU;
+const uint16_t M17_EOF_SYNC_BITS        = 0x555DU;
 
 #endif
 

M17RX.cpp

@@ -108,7 +108,7 @@ void CM17RX::processData(bool bit)
   if (m_bufferPtr > M17_FRAME_LENGTH_BITS)
     reset();
 
-  // Only search for a link setup sync in the right place +-2 symbols
+  // Only search for the syncs 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) {
@@ -117,10 +117,7 @@ void CM17RX::processData(bool bit)
       m_bufferPtr = M17_SYNC_LENGTH_BITS;
       m_state     = M17RXS_LINK_SETUP;
     }
-  }
 
-  // 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)) {
     // Fuzzy matching of the stream sync bit sequence
     if (countBits16(m_bitBuffer ^ M17_STREAM_SYNC_BITS) <= MAX_SYNC_BIT_RUN_ERRS) {
       DEBUG2("M17RX: found stream sync, pos", m_bufferPtr - M17_SYNC_LENGTH_BITS);
@@ -128,6 +125,14 @@ void CM17RX::processData(bool bit)
       m_bufferPtr = M17_SYNC_LENGTH_BITS;
       m_state     = M17RXS_STREAM;
     }
+
+    // Fuzzy matching of the eof sync bit sequence
+    if (countBits16(m_bitBuffer ^ M17_EOF_SYNC_BITS) <= MAX_SYNC_BIT_RUN_ERRS) {
+      DEBUG2("M17RX: found eof sync, pos", m_bufferPtr - M17_SYNC_LENGTH_BITS);
+      io.setDecode(false);
+      serial.writeM17EOT();
+      reset();
+    }
   }
 
   // Send a frame to the host if the required number of bits have been received

M17TX.cpp

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2009-2018,2020 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2009-2018,2020,2021 by Jonathan Naylor G4KLX
  *   Copyright (C) 2017 by Andy Uribe CA6JAU
  *
  *   This program is free software; you can redistribute it and/or modify
@@ -82,7 +82,7 @@ void CM17TX::process()
   }
 }
 
-uint8_t CM17TX::writeData(const uint8_t* data, uint8_t length)
+uint8_t CM17TX::writeLinkSetup(const uint8_t* data, uint8_t length)
 {
   if (length != (M17_FRAME_LENGTH_BYTES + 1U))
     return 4U;
@@ -97,6 +97,33 @@ uint8_t CM17TX::writeData(const uint8_t* data, uint8_t length)
   return 0U;
 }
 
+uint8_t CM17TX::writeStream(const uint8_t* data, uint8_t length)
+{
+  if (length != (M17_FRAME_LENGTH_BYTES + 1U))
+    return 4U;
+
+  uint16_t space = m_buffer.getSpace();
+  if (space < M17_FRAME_LENGTH_BYTES)
+    return 5U;
+
+  for (uint8_t i = 0U; i < M17_FRAME_LENGTH_BYTES; i++)
+    m_buffer.put(data[i + 1U]);
+
+  return 0U;
+}
+
+uint8_t CM17TX::writeEOT()
+{
+  uint16_t space = m_buffer.getSpace();
+  if (space < M17_SYNC_LENGTH_BYTES)
+    return 5U;
+
+  for (uint8_t i = 0U; i < M17_SYNC_LENGTH_BYTES; i++)
+    m_buffer.put(M17_EOF_SYNC_BYTES[i]);
+
+  return 0U;
+}
+
 void CM17TX::writeByte(uint8_t c)
 {
   uint8_t bit;

M17TX.h

@@ -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
  *   it under the terms of the GNU General Public License as published by
@@ -27,7 +27,9 @@ class CM17TX {
 public:
   CM17TX();
 
-  uint8_t writeData(const uint8_t* data, uint8_t length);
+  uint8_t writeLinkSetup(const uint8_t* data, uint8_t length);
+  uint8_t writeStream(const uint8_t* data, uint8_t length);
+  uint8_t writeEOT();
 
   void process();
 

SerialPort.cpp

@@ -64,6 +64,7 @@ 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_M17_EOT        = 0x49U;
 
 const uint8_t MMDVM_POCSAG_DATA  = 0x50U;
 
@@ -869,7 +870,7 @@ void CSerialPort::process()
           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);
+                err = m17TX.writeLinkSetup(m_buffer + 3U, m_len - 3U);
             }
             if (err == 0U) {
               if (m_modemState == STATE_IDLE)
@@ -883,7 +884,7 @@ void CSerialPort::process()
           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);
+                err = m17TX.writeStream(m_buffer + 3U, m_len - 3U);
             }
             if (err == 0U) {
               if (m_modemState == STATE_IDLE)
@@ -894,16 +895,16 @@ void CSerialPort::process()
             }
             break;
 
-          case MMDVM_M17_PACKET:
+          case MMDVM_M17_EOT:
             if (m_m17Enable) {
               if (m_modemState == STATE_IDLE || m_modemState == STATE_M17)
-                err = m17TX.writeData(m_buffer + 3U, m_len - 3U);
+                err = m17TX.writeEOT();
             }
             if (err == 0U) {
               if (m_modemState == STATE_IDLE)
                 setMode(STATE_M17);
             } else {
-              DEBUG2("Received invalid M17 packet data", err);
+              DEBUG2("Received invalid M17 EOT", err);
               sendNAK(err);
             }
             break;
@@ -1309,6 +1310,23 @@ void CSerialPort::writeM17Stream(const uint8_t* data, uint8_t length)
   writeInt(1U, reply, count);
 }
 
+void CSerialPort::writeM17EOT()
+{
+  if (m_modemState != STATE_M17 && m_modemState != STATE_IDLE)
+    return;
+
+  if (!m_m17Enable)
+    return;
+
+  uint8_t reply[3U];
+
+  reply[0U] = MMDVM_FRAME_START;
+  reply[1U] = 3U;
+  reply[2U] = MMDVM_M17_EOT;
+
+  writeInt(1U, reply, 3);
+}
+
 void CSerialPort::writeM17Lost()
 {
   if (m_modemState != STATE_M17 && m_modemState != STATE_IDLE)

SerialPort.h

@@ -54,6 +54,7 @@ public:
 
   void writeM17LinkSetup(const uint8_t* data, uint8_t length);
   void writeM17Stream(const uint8_t* data, uint8_t length);
+  void writeM17EOT();
   void writeM17Lost();
 
 #if defined(SEND_RSSI_DATA)

version.h

@@ -26,7 +26,7 @@
 #define VER_MAJOR       "1"
 #define VER_MINOR       "5"
 #define VER_REV         "2"
-#define VERSION_DATE    "20210822"
+#define VERSION_DATE    "20210826"
 
 #if defined(ZUMSPOT_ADF7021)
 #define BOARD_INFO      "ZUMspot"