Merge branch 'M17_AX25_FM' into I2C

Conf.cpp

@@ -172,6 +172,7 @@ m_nxdnRemoteGateway(false),
 m_nxdnTXHang(5U),
 m_nxdnModeHang(10U),
 m_m17Enabled(false),
+m_m17ColorCode(1U),
 m_m17SelfOnly(false),
 m_m17AllowEncryption(false),
 m_m17TXHang(5U),
@@ -740,6 +741,8 @@ bool CConf::read()
 		} else if (section == SECTION_M17) {
 			if (::strcmp(key, "Enable") == 0)
 				m_m17Enabled = ::atoi(value) == 1;
+			else if (::strcmp(key, "ColorCode") == 0)
+				m_m17ColorCode = (unsigned int)::atoi(value);
 			else if (::strcmp(key, "SelfOnly") == 0)
 				m_m17SelfOnly = ::atoi(value) == 1;
 			else if (::strcmp(key, "AllowEncryption") == 0)
@@ -1606,6 +1609,11 @@ bool CConf::getM17Enabled() const
 	return m_m17Enabled;
 }
 
+unsigned int CConf::getM17ColorCode() const
+{
+	return m_m17ColorCode;
+}
+
 bool CConf::getM17SelfOnly() const
 {
 	return m_m17SelfOnly;

Conf.h

@@ -163,6 +163,7 @@ public:
 
   // The M17 section
   bool         getM17Enabled() const;
+  unsigned int getM17ColorCode() const;
   bool         getM17SelfOnly() const;
   bool         getM17AllowEncryption() const;
   unsigned int getM17TXHang() const;
@@ -470,6 +471,7 @@ private:
   unsigned int m_nxdnModeHang;
 
   bool         m_m17Enabled;
+  unsigned int m_m17ColorCode;
   bool         m_m17SelfOnly;
   bool         m_m17AllowEncryption;
   unsigned int m_m17TXHang;

M17Control.cpp

@@ -57,8 +57,9 @@ const unsigned char BIT_MASK_TABLE[] = { 0x80U, 0x40U, 0x20U, 0x10U, 0x08U, 0x04
 #define WRITE_BIT(p,i,b) p[(i)>>3] = (b) ? (p[(i)>>3] | BIT_MASK_TABLE[(i)&7]) : (p[(i)>>3] & ~BIT_MASK_TABLE[(i)&7])
 #define READ_BIT(p,i)    (p[(i)>>3] & BIT_MASK_TABLE[(i)&7])
 
-CM17Control::CM17Control(const std::string& callsign, bool selfOnly, bool allowEncryption, CM17Network* network, CDisplay* display, unsigned int timeout, bool duplex, CRSSIInterpolator* rssiMapper) :
+CM17Control::CM17Control(const std::string& callsign, unsigned int colorCode, bool selfOnly, bool allowEncryption, CM17Network* network, CDisplay* display, unsigned int timeout, bool duplex, CRSSIInterpolator* rssiMapper) :
 m_callsign(callsign),
+m_colorCode(colorCode),
 m_selfOnly(selfOnly),
 m_allowEncryption(allowEncryption),
 m_network(network),
@@ -78,7 +79,9 @@ m_rfFN(0U),
 m_rfErrs(0U),
 m_rfBits(1U),
 m_rfLICH(),
+m_rfLICHn(0U),
 m_netLICH(),
+m_netLICHn(0U),
 m_rssiMapper(rssiMapper),
 m_rssi(0U),
 m_maxRSSI(0U),
@@ -154,7 +157,7 @@ bool CM17Control::writeModem(unsigned char* data, unsigned int len)
 	decorrelator(data + 2U, temp);
 	interleaver(temp, data + 2U);
 
-	if (m_rfState == RS_RF_LISTENING) {
+	if (m_rfState == RS_RF_LISTENING && data[0U] == TAG_HEADER) {
 		m_rfLICH.reset();
 
 		CM17Convolution conv;
@@ -171,6 +174,7 @@ bool CM17Control::writeModem(unsigned char* data, unsigned int len)
 			m_maxRSSI = m_rssi;
 			m_aveRSSI = m_rssi;
 			m_rssiCount = 1U;
+			m_rfLICHn   = 0U;
 			m_rfFN      = 0U;
 
 #if defined(DUMP_M17)
@@ -178,72 +182,7 @@ bool CM17Control::writeModem(unsigned char* data, unsigned int len)
 #endif
 			m_rfLICH.setLinkSetup(frame);
 
-			std::string source = m_rfLICH.getSource();
+			m_rfState = RS_RF_LATE_ENTRY;
-			std::string dest   = m_rfLICH.getDest();
-
-			if (m_selfOnly) {
-				bool ret = checkCallsign(source);
-				if (!ret) {
-					LogMessage("M17, invalid access attempt from %s to %s", source.c_str(), dest.c_str());
-					m_rfState = RS_RF_REJECTED;
-					return false;
-				}
-			}
-
-			if (!m_allowEncryption) {
-				bool ret = m_rfLICH.isNONCENull();
-				if (!ret) {
-					LogMessage("M17, invalid access attempt from %s to %s", source.c_str(), dest.c_str());
-					m_rfState = RS_RF_REJECTED;
-					return false;
-				}
-			}
-
-			unsigned char dataType = m_rfLICH.getDataType();
-			switch (dataType) {
-			case 1U:
-				LogMessage("M17, received RF data transmission from %s to %s", source.c_str(), dest.c_str());
-				m_rfState = RS_RF_DATA;
-				break;
-			case 2U:
-				LogMessage("M17, received RF voice transmission from %s to %s", source.c_str(), dest.c_str());
-				m_rfState = RS_RF_AUDIO;
-				break;
-			case 3U:
-				LogMessage("M17, received RF voice + data transmission from %s to %s", source.c_str(), dest.c_str());
-				m_rfState = RS_RF_AUDIO;
-				break;
-			default:
-				LogMessage("M17, received RF unknown transmission from %s to %s", source.c_str(), dest.c_str());
-				m_rfState = RS_RF_DATA;
-				break;
-			}
-
-			m_display->writeM17(source.c_str(), dest.c_str(), "R");
-
-#if defined(DUMP_M17)
-			writeFile(data + 2U);
-#endif
-			if (m_duplex) {
-				data[0U] = TAG_DATA;
-				data[1U] = 0x00U;
-
-				// Generate the sync
-				CSync::addM17Sync(data + 2U);
-
-				unsigned char setup[M17_LICH_LENGTH_BYTES];
-				m_rfLICH.getLinkSetup(setup);
-
-				// Add the convolution FEC
-				CM17Convolution conv;
-				conv.encodeLinkSetup(setup, data + 2U + M17_SYNC_LENGTH_BYTES);
-
-				unsigned char temp[M17_FRAME_LENGTH_BYTES];
-				interleaver(data + 2U, temp);
-				decorrelator(temp, data + 2U);
-
-				writeQueueRF(data);
-			}
 
 			return true;
 		} else {
@@ -251,15 +190,7 @@ bool CM17Control::writeModem(unsigned char* data, unsigned int len)
 		}
 	}
 
-	if (m_rfState == RS_RF_LATE_ENTRY) {
+	if (m_rfState == RS_RF_LATE_ENTRY && data[0U] == TAG_DATA) {
-		CM17Convolution conv;
-		unsigned char frame[M17_FN_LENGTH_BYTES + M17_PAYLOAD_LENGTH_BYTES + M17_CRC_LENGTH_BYTES];
-		conv.decodeData(data + 2U + M17_SYNC_LENGTH_BYTES + M17_LICH_FRAGMENT_FEC_LENGTH_BYTES, frame);
-
-		bool valid = CM17CRC::checkCRC(frame, M17_FN_LENGTH_BYTES + M17_PAYLOAD_LENGTH_BYTES + M17_CRC_LENGTH_BYTES);
-		if (valid) {
-			m_rfFN = (frame[0U] << 8) + (frame[1U] << 0);
-
 		unsigned int frag1, frag2, frag3, frag4;
 		CM17Utils::splitFragmentLICHFEC(data + 2U + M17_SYNC_LENGTH_BYTES, frag1, frag2, frag3, frag4);
 
@@ -268,12 +199,22 @@ bool CM17Control::writeModem(unsigned char* data, unsigned int len)
 		unsigned int lich3 = CGolay24128::decode24128(frag3);
 		unsigned int lich4 = CGolay24128::decode24128(frag4);
 
+		unsigned int colorCode = (lich4 >> 7) & 0x1FU;
+		if (colorCode != m_colorCode)
+			return false;
+
+		bool lateEntry = false;
+		if (!m_rfLICH.isValid()) {
 			unsigned char lich[M17_LICH_FRAGMENT_LENGTH_BYTES];
 			CM17Utils::combineFragmentLICH(lich1, lich2, lich3, lich4, lich);
 
-			m_rfLICH.setFragment(lich, m_rfFN);
+			unsigned int n = (lich4 >> 4) & 0x07U;
+			m_rfLICH.setFragment(lich, n);
 
-			valid = m_rfLICH.isValid();
+			lateEntry = true;
+		}
+
+		bool valid = m_rfLICH.isValid();
 		if (valid) {
 			m_rfFrames = 0U;
 			m_rfErrs = 0U;
@@ -283,6 +224,7 @@ bool CM17Control::writeModem(unsigned char* data, unsigned int len)
 			m_maxRSSI = m_rssi;
 			m_aveRSSI = m_rssi;
 			m_rssiCount = 1U;
+			m_rfLICHn   = 0U;
 
 #if defined(DUMP_M17)
 			openFile();
@@ -302,19 +244,19 @@ bool CM17Control::writeModem(unsigned char* data, unsigned int len)
 			unsigned char dataType = m_rfLICH.getDataType();
 			switch (dataType) {
 			case 1U:
-					LogMessage("M17, received RF late entry data transmission from %s to %s", source.c_str(), dest.c_str());
+				LogMessage("M17, received RF %s data transmission from %s to %s", lateEntry ? "late entry" : "", source.c_str(), dest.c_str());
 				m_rfState = RS_RF_DATA;
 				break;
 			case 2U:
-					LogMessage("M17, received RF late entry voice transmission from %s to %s", source.c_str(), dest.c_str());
+				LogMessage("M17, received RF %s voice transmission from %s to %s", lateEntry ? "late entry" : "", source.c_str(), dest.c_str());
 				m_rfState = RS_RF_AUDIO;
 				break;
 			case 3U:
-					LogMessage("M17, received RF late entry voice + data transmission from %s to %s", source.c_str(), dest.c_str());
+				LogMessage("M17, received RF %s voice + data transmission from %s to %s", lateEntry ? "late entry" : "", source.c_str(), dest.c_str());
 				m_rfState = RS_RF_AUDIO;
 				break;
 			default:
-					LogMessage("M17, received RF late entry unknown transmission from %s to %s", source.c_str(), dest.c_str());
+				LogMessage("M17, received RF %s unknown transmission from %s to %s", lateEntry ? "late entry" : "", source.c_str(), dest.c_str());
 				m_rfState = RS_RF_DATA;
 				break;
 			}
@@ -323,11 +265,11 @@ bool CM17Control::writeModem(unsigned char* data, unsigned int len)
 
 			if (m_duplex) {
 				// Create a Link Setup frame
-					data[0U] = TAG_DATA;
+				data[0U] = TAG_HEADER;
 				data[1U] = 0x00U;
 
 				// Generate the sync
-					CSync::addM17Sync(data + 2U);
+				CSync::addM17HeaderSync(data + 2U);
 				
 				unsigned char setup[M17_LICH_LENGTH_BYTES];
 				m_rfLICH.getLinkSetup(setup);
@@ -346,9 +288,8 @@ bool CM17Control::writeModem(unsigned char* data, unsigned int len)
 			// Fall through to the next section
 		}
 	}
-	}
 
-	if (m_rfState == RS_RF_AUDIO || m_rfState == RS_RF_DATA) {
+	if ((m_rfState == RS_RF_AUDIO || m_rfState == RS_RF_DATA) && data[0U] == TAG_DATA) {
 #if defined(DUMP_M17)
 		writeFile(data + 2U);
 #endif
@@ -391,14 +332,18 @@ bool CM17Control::writeModem(unsigned char* data, unsigned int len)
 		rfData[1U] = 0x00U;
 
 		// Generate the sync
-		CSync::addM17Sync(rfData + 2U);
+		CSync::addM17DataSync(rfData + 2U);
 
 		unsigned char lich[M17_LICH_FRAGMENT_LENGTH_BYTES];
-		m_netLICH.getFragment(lich, m_rfFN);
+		m_netLICH.getFragment(lich, m_rfLICHn);
 
 		unsigned int frag1, frag2, frag3, frag4;
 		CM17Utils::splitFragmentLICH(lich, frag1, frag2, frag3, frag4);
 
+		// Add the Color Code and fragment number
+		frag4 |= (m_rfLICHn & 0x07U)   << 4;
+		frag4 |= (m_colorCode & 0x1FU) << 7;
+
 		// Add Golay to the LICH fragment here
 		unsigned int lich1 = CGolay24128::encode24128(frag1);
 		unsigned int lich2 = CGolay24128::encode24128(frag2);
@@ -445,6 +390,10 @@ bool CM17Control::writeModem(unsigned char* data, unsigned int len)
 
 		m_rfFrames++;
 
+		m_rfLICHn++;
+		if (m_rfLICHn >= 6U)
+			m_rfLICHn = 0U;
+
 		// EOT?
 		if ((m_rfFN & 0x8000U) == 0x8000U) {
 			std::string source = m_rfLICH.getSource();
@@ -460,7 +409,7 @@ bool CM17Control::writeModem(unsigned char* data, unsigned int len)
 		return true;
 	}
 
-	if (m_rfState == RS_RF_REJECTED) {
+	if (m_rfState == RS_RF_REJECTED && data[0U] == TAG_DATA) {
 		CM17Convolution conv;
 		unsigned char frame[M17_FN_LENGTH_BYTES + M17_PAYLOAD_LENGTH_BYTES + M17_CRC_LENGTH_BYTES];
 		conv.decodeData(data + 2U + M17_SYNC_LENGTH_BYTES + M17_LICH_FRAGMENT_FEC_LENGTH_BYTES, frame);
@@ -500,6 +449,8 @@ void CM17Control::writeEndRF()
 
 	m_rfTimeoutTimer.stop();
 
+	m_rfLICH.reset();
+
 	if (m_netState == RS_NET_IDLE) {
 		m_display->clearM17();
 
@@ -520,6 +471,8 @@ void CM17Control::writeEndNet()
 	m_networkWatchdog.stop();
 	m_packetTimer.stop();
 
+	m_netLICH.reset();
+
 	m_display->clearM17();
 
 	if (m_network != NULL)
@@ -579,15 +532,16 @@ void CM17Control::writeNetwork()
 		m_packetTimer.start();
 		m_elapsed.start();
 		m_netFrames = 0U;
+		m_netLICHn  = 0U;
 
 		// Create a dummy start message
 		unsigned char start[M17_FRAME_LENGTH_BYTES + 2U];
 
-		start[0U] = TAG_DATA;
+		start[0U] = TAG_HEADER;
 		start[1U] = 0x00U;
 
 		// Generate the sync
-		CSync::addM17Sync(start + 2U);
+		CSync::addM17HeaderSync(start + 2U);
 
 		unsigned char setup[M17_LICH_LENGTH_BYTES];
 		m_netLICH.getLinkSetup(setup);
@@ -609,19 +563,21 @@ void CM17Control::writeNetwork()
 	data[1U] = 0x00U;
 
 	// Generate the sync
-	CSync::addM17Sync(data + 2U);
+	CSync::addM17DataSync(data + 2U);
 
 	m_netFrames++;
 
 	// Add the fragment LICH
-	uint16_t fn = (netData[28U] << 8) + (netData[29U] << 0);
-
 	unsigned char lich[M17_LICH_FRAGMENT_LENGTH_BYTES];
-	m_netLICH.getFragment(lich, fn);
+	m_netLICH.getFragment(lich, m_netLICHn);
 
 	unsigned int frag1, frag2, frag3, frag4;
 	CM17Utils::splitFragmentLICH(lich, frag1, frag2, frag3, frag4);
 
+	// Add the Color Code and fragment number
+	frag4 |= (m_netLICHn & 0x07U)  << 4;
+	frag4 |= (m_colorCode & 0x1FU) << 7;
+
 	// Add Golay to the LICH fragment here
 	unsigned int lich1 = CGolay24128::encode24128(frag1);
 	unsigned int lich2 = CGolay24128::encode24128(frag2);
@@ -647,7 +603,12 @@ void CM17Control::writeNetwork()
 
 	writeQueueNet(data);
 
+	m_netLICHn++;
+	if (m_netLICHn >= 6U)
+		m_netLICHn = 0U;
+
 	// EOT handling
+	uint16_t fn = (netData[28U] << 8) + (netData[29U] << 0);
 	if ((fn & 0x8000U) == 0x8000U) {
 		std::string source = m_netLICH.getSource();
 		std::string dest   = m_netLICH.getDest();

M17Control.h

@@ -34,7 +34,7 @@
 
 class CM17Control {
 public:
-	CM17Control(const std::string& callsign, bool selfOnly, bool allowEncryption, CM17Network* network, CDisplay* display, unsigned int timeout, bool duplex, CRSSIInterpolator* rssiMapper);
+	CM17Control(const std::string& callsign, unsigned int colorCode, bool selfOnly, bool allowEncryption, CM17Network* network, CDisplay* display, unsigned int timeout, bool duplex, CRSSIInterpolator* rssiMapper);
 	~CM17Control();
 
 	bool writeModem(unsigned char* data, unsigned int len);
@@ -49,6 +49,7 @@ public:
 
 private:
 	std::string                m_callsign;
+	unsigned int               m_colorCode;
 	bool                       m_selfOnly;
 	bool                       m_allowEncryption;
 	CM17Network*               m_network;
@@ -68,7 +69,9 @@ private:
 	unsigned int               m_rfErrs;
 	unsigned int               m_rfBits;
 	CM17LICH                   m_rfLICH;
+	unsigned int               m_rfLICHn;
 	CM17LICH                   m_netLICH;
+	unsigned int               m_netLICHn;
 	CRSSIInterpolator*         m_rssiMapper;
 	unsigned char              m_rssi;
 	unsigned char              m_maxRSSI;

M17Defines.h

@@ -24,14 +24,16 @@ const unsigned int M17_RADIO_SYMBOL_LENGTH = 5U;      // At 24 kHz sample rate
 const unsigned int M17_FRAME_LENGTH_BITS    = 384U;
 const unsigned int M17_FRAME_LENGTH_BYTES   = M17_FRAME_LENGTH_BITS / 8U;
 
-const unsigned char M17_SYNC_BYTES[] = {0x32U, 0x43U};
+const unsigned char M17_HEADER_SYNC_BYTES[] = {0x5DU, 0xDDU};
+const unsigned char M17_DATA_SYNC_BYTES[]   = {0xDDU, 0xDDU};
+
 const unsigned int  M17_SYNC_LENGTH_BITS  = 16U;
 const unsigned int  M17_SYNC_LENGTH_BYTES = M17_SYNC_LENGTH_BITS / 8U;
 
 const unsigned int M17_LICH_LENGTH_BITS  = 240U;
 const unsigned int M17_LICH_LENGTH_BYTES = M17_LICH_LENGTH_BITS / 8U;
 
-const unsigned int M17_LICH_FRAGMENT_LENGTH_BITS  = M17_LICH_LENGTH_BITS / 5U;
+const unsigned int M17_LICH_FRAGMENT_LENGTH_BITS  = M17_LICH_LENGTH_BITS / 6U;
 const unsigned int M17_LICH_FRAGMENT_LENGTH_BYTES = M17_LICH_FRAGMENT_LENGTH_BITS / 8U;
 
 const unsigned int M17_LICH_FRAGMENT_FEC_LENGTH_BITS  = M17_LICH_FRAGMENT_LENGTH_BITS * 2U;

M17LICH.cpp

@@ -124,23 +124,19 @@ void CM17LICH::setLinkSetup(const unsigned char* data)
 	m_valid = CM17CRC::checkCRC(m_lich, M17_LICH_LENGTH_BYTES);
 }
 
-void CM17LICH::getFragment(unsigned char* data, unsigned short fn) const
+void CM17LICH::getFragment(unsigned char* data, unsigned int n) const
 {
 	assert(data != NULL);
 
 	CM17CRC::encodeCRC(m_lich, M17_LICH_LENGTH_BYTES);
 
-	unsigned int n = (fn & 0x7FFFU) % 5U;
-
 	::memcpy(data, m_lich + (n * M17_LICH_FRAGMENT_LENGTH_BYTES), M17_LICH_FRAGMENT_LENGTH_BYTES);
 }
 
-void CM17LICH::setFragment(const unsigned char* data, unsigned short fn)
+void CM17LICH::setFragment(const unsigned char* data, unsigned int n)
 {
 	assert(data != NULL);
 
-	unsigned int n = (fn & 0x7FFFU) % 5U;
-
 	::memcpy(m_lich + (n * M17_LICH_FRAGMENT_LENGTH_BYTES), data, M17_LICH_FRAGMENT_LENGTH_BYTES);
 
 	m_valid = CM17CRC::checkCRC(m_lich, M17_LICH_LENGTH_BYTES);

M17LICH.h

@@ -46,8 +46,8 @@ public:
 	void getLinkSetup(unsigned char* data) const;
 	void setLinkSetup(const unsigned char* data);
 
-	void getFragment(unsigned char* data, unsigned short fn) const;
+	void getFragment(unsigned char* data, unsigned int n) const;
-	void setFragment(const unsigned char* data, unsigned short fn);
+	void setFragment(const unsigned char* data, unsigned int n);
 
 private:
 	unsigned char* m_lich;

MMDVM.ini

@@ -133,6 +133,7 @@ TXHang=5
 
 [M17]
 Enable=1
+ColorCode=3
 SelfOnly=0
 TXHang=5
 # ModeHang=10

MMDVMHost.cpp

@@ -620,17 +620,19 @@ int CMMDVMHost::run()
 
 	if (m_m17Enabled) {
 		bool selfOnly          = m_conf.getM17SelfOnly();
+		unsigned int colorCode = m_conf.getM17ColorCode();
 		bool allowEncryption   = m_conf.getM17AllowEncryption();
 		unsigned int txHang    = m_conf.getM17TXHang();
 		m_m17RFModeHang        = m_conf.getM17ModeHang();
 
 		LogInfo("M17 RF Parameters");
 		LogInfo("    Self Only: %s", selfOnly ? "yes" : "no");
+		LogInfo("    Color Code: %u", colorCode);
 		LogInfo("    Allow Encryption: %s", allowEncryption ? "yes" : "no");
 		LogInfo("    TX Hang: %us", txHang);
 		LogInfo("    Mode Hang: %us", m_m17RFModeHang);
 
-		m_m17 = new CM17Control(m_callsign, selfOnly, allowEncryption, m_m17Network, m_display, m_timeout, m_duplex, rssi);
+		m_m17 = new CM17Control(m_callsign, colorCode, selfOnly, allowEncryption, m_m17Network, m_display, m_timeout, m_duplex, rssi);
 	}
 
 	CTimer pocsagTimer(1000U, 30U);

SerialModem.cpp

@@ -79,8 +79,9 @@ const unsigned char MMDVM_P25_LOST    = 0x32U;
 const unsigned char MMDVM_NXDN_DATA   = 0x40U;
 const unsigned char MMDVM_NXDN_LOST   = 0x41U;
 
-const unsigned char MMDVM_M17_DATA    = 0x45U;
+const unsigned char MMDVM_M17_HEADER  = 0x45U;
-const unsigned char MMDVM_M17_LOST    = 0x46U;
+const unsigned char MMDVM_M17_DATA    = 0x46U;
+const unsigned char MMDVM_M17_LOST    = 0x47U;
 
 const unsigned char MMDVM_POCSAG_DATA = 0x50U;
 
@@ -661,6 +662,20 @@ void CSerialModem::clock(unsigned int ms)
 			}
 			break;
 
+			case MMDVM_M17_HEADER: {
+				if (m_trace)
+					CUtils::dump(1U, "RX M17 Header", m_buffer, m_length);
+
+				unsigned char data = m_length - 2U;
+				m_rxM17Data.addData(&data, 1U);
+
+				data = TAG_HEADER;
+				m_rxM17Data.addData(&data, 1U);
+
+				m_rxM17Data.addData(m_buffer + 3U, m_length - 3U);
+			}
+			break;
+
 			case MMDVM_M17_DATA: {
 				if (m_trace)
 					CUtils::dump(1U, "RX M17 Data", m_buffer, m_length);
@@ -1017,8 +1032,12 @@ void CSerialModem::clock(unsigned int ms)
 		m_txM17Data.getData(&len, 1U);
 		m_txM17Data.getData(m_buffer, len);
 
-		if (m_trace)
+		if (m_trace) {
+			if (m_buffer[2U] == MMDVM_M17_HEADER)
+				CUtils::dump(1U, "TX M17 Header", m_buffer, len);
+			else
 				CUtils::dump(1U, "TX M17 Data", m_buffer, len);
+		}
 
 		int ret = m_serial->write(m_buffer, len);
 		if (ret != int(len))
@@ -1460,13 +1479,17 @@ bool CSerialModem::writeM17Data(const unsigned char* data, unsigned int length)
 	assert(data != NULL);
 	assert(length > 0U);
 
-	if (data[0U] != TAG_DATA && data[0U] != TAG_EOT)
+	if (data[0U] != TAG_HEADER && data[0U] != TAG_DATA && data[0U] != TAG_EOT)
 		return false;
 
 	unsigned char buffer[130U];
 
 	buffer[0U] = MMDVM_FRAME_START;
 	buffer[1U] = length + 2U;
+
+	if (data[0U] == TAG_HEADER)
+		buffer[2U] = MMDVM_M17_HEADER;
+	else
 		buffer[2U] = MMDVM_M17_DATA;
 
 	::memcpy(buffer + 3U, data + 1U, length - 1U);

Sync.cpp

@@ -85,9 +85,16 @@ void CSync::addNXDNSync(unsigned char* data)
 		data[i] = (data[i] & ~NXDN_FSW_BYTES_MASK[i]) | NXDN_FSW_BYTES[i];
 }
 
-void CSync::addM17Sync(unsigned char* data)
+void CSync::addM17HeaderSync(unsigned char* data)
 {
 	assert(data != NULL);
 
-	::memcpy(data, M17_SYNC_BYTES, M17_SYNC_LENGTH_BYTES);
+	::memcpy(data, M17_HEADER_SYNC_BYTES, M17_SYNC_LENGTH_BYTES);
+}
+
+void CSync::addM17DataSync(unsigned char* data)
+{
+	assert(data != NULL);
+
+	::memcpy(data, M17_DATA_SYNC_BYTES, M17_SYNC_LENGTH_BYTES);
 }

Sync.h

@@ -33,7 +33,8 @@ public:
 
 	static void addNXDNSync(unsigned char* data);
 
-	static void addM17Sync(unsigned char* data);
+	static void addM17HeaderSync(unsigned char* data);
+	static void addM17DataSync(unsigned char* data);
 
 private:
 };

Version.h

@@ -19,6 +19,6 @@
 #if !defined(VERSION_H)
 #define	VERSION_H
 
-const char* VERSION = "20201124";
+const char* VERSION = "20201126";
 
 #endif