From 4bfae22ef0327c38aff61d6769694e6de9a2005a Mon Sep 17 00:00:00 2001 From: Andy CA6JAU Date: Tue, 17 Jul 2018 23:58:42 -0400 Subject: [PATCH] Add G4KLX (MMDVM firmware) improvement for "transmission lost" in D-Star --- DStarRX.cpp | 59 +++++++++++++++++++++++++++-------------------------- DStarRX.h | 1 + 2 files changed, 31 insertions(+), 29 deletions(-) diff --git a/DStarRX.cpp b/DStarRX.cpp index 57f8659..cc8411e 100644 --- a/DStarRX.cpp +++ b/DStarRX.cpp @@ -22,11 +22,7 @@ #include "DStarRX.h" #include "Utils.h" -const unsigned int MAX_SYNC_BITS = 50U * DSTAR_DATA_LENGTH_BITS; - -const unsigned int SYNC_POS = 21U * DSTAR_DATA_LENGTH_BITS; -const unsigned int SYNC_SCAN_START = SYNC_POS - 3U; -const unsigned int SYNC_SCAN_END = SYNC_POS + 3U; +const unsigned int MAX_SYNC_BITS = 100U * DSTAR_DATA_LENGTH_BITS; // D-Star preamble sequence (only 32 bits of 101010...) const uint32_t PREAMBLE_MASK = 0xFFFFFFFFU; @@ -41,7 +37,7 @@ const uint8_t FRAME_SYNC_ERRS = 2U; // D-Star bit order version of 0x55 0x2D 0x16 const uint32_t DATA_SYNC_DATA = 0x00AAB468U; const uint32_t DATA_SYNC_MASK = 0x00FFFFFFU; -const uint8_t DATA_SYNC_ERRS = 2U; +const uint8_t DATA_SYNC_ERRS = 3U; // D-Star bit order version of 0x55 0x55 0xC8 0x7A const uint32_t END_SYNC_DATA = 0xAAAA135EU; @@ -312,7 +308,7 @@ void CDStarRX::processNone(bool bit) // Exact matching of the data sync bit sequence if (countBits32((m_patternBuffer & DATA_SYNC_MASK) ^ DATA_SYNC_DATA) == 0U) { DEBUG1("DStarRX: found data sync in None, exact"); - + io.setDecode(true); ::memcpy(m_rxBuffer, DSTAR_DATA_SYNC_BYTES, DSTAR_DATA_LENGTH_BYTES); @@ -321,7 +317,7 @@ void CDStarRX::processNone(bool bit) ::memset(m_rxBuffer, 0x00U, DSTAR_DATA_LENGTH_BYTES + 2U); m_rxBufferBits = 0U; - m_dataBits = 0U; + m_dataBits = MAX_SYNC_BITS; m_rxState = DSRXS_DATA; return; } @@ -343,14 +339,14 @@ void CDStarRX::processHeader(bool bit) bool ok = rxHeader(m_rxBuffer, header); if (ok) { io.setDecode(true); - - serial.writeDStarHeader(header, DSTAR_HEADER_LENGTH_BYTES); + + writeRSSIHeader(header); ::memset(m_rxBuffer, 0x00U, DSTAR_DATA_LENGTH_BYTES + 2U); m_rxBufferBits = 0U; m_rxState = DSRXS_DATA; - m_dataBits = SYNC_POS - DSTAR_DATA_LENGTH_BITS + 1U; + m_dataBits = MAX_SYNC_BITS; } else { // The checksum failed, return to looking for syncs m_rxState = DSRXS_NONE; @@ -371,7 +367,7 @@ void CDStarRX::processData(bool bit) if (countBits32((m_patternBuffer & END_SYNC_MASK) ^ END_SYNC_DATA) <= END_SYNC_ERRS) { DEBUG1("DStarRX: Found end sync in Data"); io.setDecode(false); - + serial.writeDStarEOT(); m_rxState = DSRXS_NONE; @@ -380,42 +376,33 @@ void CDStarRX::processData(bool bit) // Fuzzy matching of the data sync bit sequence bool syncSeen = false; - if (m_dataBits >= SYNC_SCAN_START && m_dataBits <= (SYNC_POS + 1U)) { + if (m_rxBufferBits >= (DSTAR_DATA_LENGTH_BITS - 3U)) { if (countBits32((m_patternBuffer & DATA_SYNC_MASK) ^ DATA_SYNC_DATA) <= DATA_SYNC_ERRS) { - if (m_dataBits < SYNC_POS) { - DEBUG2("DStarRX: found data sync in Data, early", SYNC_POS - m_dataBits); - } - else { - DEBUG1("DStarRX: found data sync in Data"); - } - m_rxBufferBits = DSTAR_DATA_LENGTH_BITS; - m_dataBits = 0U; - syncSeen = true; + m_dataBits = MAX_SYNC_BITS; + syncSeen = true; } } // Check to see if the sync is arriving late - if (m_dataBits == SYNC_POS) { + if (m_rxBufferBits == DSTAR_DATA_LENGTH_BITS && !syncSeen) { for (uint8_t i = 1U; i <= 3U; i++) { uint32_t syncMask = DATA_SYNC_MASK >> i; uint32_t syncData = DATA_SYNC_DATA >> i; if (countBits32((m_patternBuffer & syncMask) ^ syncData) <= DATA_SYNC_ERRS) { - DEBUG2("DStarRX: found data sync in Data, late", i); m_rxBufferBits -= i; - m_dataBits -= i; break; } } } - m_dataBits++; + m_dataBits--; // We've not seen a data sync for too long, signal RXLOST and change to RX_NONE - if (m_dataBits >= MAX_SYNC_BITS) { + if (m_dataBits == 0U) { DEBUG1("DStarRX: data sync timed out, lost lock"); io.setDecode(false); - + serial.writeDStarLost(); m_rxState = DSRXS_NONE; @@ -431,7 +418,7 @@ void CDStarRX::processData(bool bit) writeRSSIData(m_rxBuffer); } else serial.writeDStarData(m_rxBuffer, DSTAR_DATA_LENGTH_BYTES); - + io.setDecode(true); // Start the next frame @@ -656,6 +643,20 @@ bool CDStarRX::checksum(const uint8_t* header) const return crc8[0U] == header[DSTAR_HEADER_LENGTH_BYTES - 2U] && crc8[1U] == header[DSTAR_HEADER_LENGTH_BYTES - 1U]; } +void CDStarRX::writeRSSIHeader(unsigned char* header) +{ +#if defined(SEND_RSSI_DATA) + uint16_t rssi = io.readRSSI(); + + header[41U] = (rssi >> 8) & 0xFFU; + header[42U] = (rssi >> 0) & 0xFFU; + + serial.writeDStarHeader(header, DSTAR_HEADER_LENGTH_BYTES + 2U); +#else + serial.writeDStarHeader(header, DSTAR_HEADER_LENGTH_BYTES + 0U); +#endif +} + void CDStarRX::writeRSSIData(unsigned char* data) { #if defined(SEND_RSSI_DATA) diff --git a/DStarRX.h b/DStarRX.h index b6b17ac..589914d 100644 --- a/DStarRX.h +++ b/DStarRX.h @@ -58,6 +58,7 @@ private: void viterbiDecode(int* data); void traceBack(); bool checksum(const uint8_t* header) const; + void writeRSSIHeader(unsigned char* header); void writeRSSIData(unsigned char* data); };