WIP

latest/Firmware/Inc/NoiseFloorDetector.hpp

@@ -34,7 +34,7 @@ public:
   // Called directly by each receiver to report every RSSI reading at every SOTDMA slot
   void report(char channel, uint8_t rssi);
 
-  void reset();
+  void recalculate();
 
   // Returns the current noise floor of the channel, 0xff if unknown
   uint8_t getNoiseFloor(char channel);

latest/Firmware/Inc/config.h

@@ -73,8 +73,18 @@
 // Maximum allowed backlog in TX queue
 #define MAX_TX_PACKETS_IN_QUEUE        4
 
+
+// Set to true to force RSSI sampling at every SOTDMA timer slot on both channels
+#define FULL_RSSI_SAMPLING             1
+
 // Headroom above noise floor (in dB) that constitutes a clear channel for transmission
-#define TX_CCA_HEADROOM                3
+#if FULL_RSSI_SAMPLING
+#define TX_CCA_HEADROOM                2
+#else
+// When sampling RSSI sparsely, there is a tendency to overestimate the noise floor, so there is no need for headroom
+#define TX_CCA_HEADROOM                0
+#endif
+
 
 // Transmission intervals in seconds
 #define MIN_TX_INTERVAL                5

latest/Firmware/Src/AISMessages.cpp

@@ -107,8 +107,8 @@ void AISMessage::addString(uint8_t *bitVector, uint16_t &size, const string &val
   ASSERT(value.length() <= maxChars);
   ASSERT(maxChars < 30); // There should be no application for such long strings here
   char s[30];
-  memset(s, 0, sizeof s);
+  //memset(s, 0, sizeof s);
-  strncpy(s, value.c_str(), value.length());
+  strlcpy(s, value.c_str(), sizeof s);
 
   uint8_t buffer[32];
   for ( uint8_t c = 0; c < maxChars; ++c ) {

latest/Firmware/Src/CommandProcessor.cpp

@@ -107,8 +107,8 @@ void CommandProcessor::processCommand(const char *buff)
 
       memset(&station, 0, sizeof station);
       station.mmsi = Utils::toInt(tokens[0]);
-      strncpy(station.name, tokens[1].c_str(), sizeof station.name);
+      strlcpy(station.name, tokens[1].c_str(), sizeof station.name);
-      strncpy(station.callsign, tokens[2].c_str(), sizeof station.callsign);
+      strlcpy(station.callsign, tokens[2].c_str(), sizeof station.callsign);
       int type = (VesselType)Utils::toInt(tokens[3]);
       if ( type == 30 || type == 34 || type == 36 || type == 37 )
         station.type = (VesselType)type;

latest/Firmware/Src/DataTerminal.cpp

@@ -112,7 +112,7 @@ void termInputCB(char c)
     {
       __rxbuff[__rxpos++] = 0;
       Event *e = EventPool::instance().newEvent(COMMAND_EVENT);
-      strncpy(e->command.buffer, __rxbuff, sizeof e->command.buffer);
+      strlcpy(e->command.buffer, __rxbuff, sizeof e->command.buffer);
       EventQueue::instance().push(e);
     }
 }

latest/Firmware/Src/GPS.cpp

@@ -116,7 +116,7 @@ void GPS::onRX(char c)
       Event *e = EventPool::instance().newEvent(GPS_NMEA_SENTENCE);
       if ( e )
         {
-          strncpy(e->nmeaBuffer.sentence, mBuff, sizeof e->nmeaBuffer.sentence);
+          strlcpy(e->nmeaBuffer.sentence, mBuff, sizeof e->nmeaBuffer.sentence);
           EventQueue::instance ().push(e);
         }
       mBuffPos = 0;

latest/Firmware/Src/NoiseFloorDetector.cpp

@@ -46,18 +46,9 @@ NoiseFloorDetector::NoiseFloorDetector()
 
 void NoiseFloorDetector::report(char channel, uint8_t rssi)
 {
-  if ( rssi < 0x20 ) // Not realistic, likely a bug
+  if ( rssi < 0x32 ) // Not realistic, likely a bug
     return;
 
-#if 0
-  processSample(channel == 'A' ? mChannelASamples : mChannelBSamples, rssi);
-
-  if ( channel == 'A' )
-    mChannelACurrent = medianValue(mChannelASamples);
-  else
-    mChannelBCurrent = medianValue(mChannelBSamples);
-#endif
-
   if ( channel == 'A' )
     {
       mAFloor = min(mAFloor, rssi);
@@ -90,61 +81,16 @@ void NoiseFloorDetector::processEvent(const Event &e)
     if ( mTicks == 30 )
       {
         //DBG("Event pool utilization = %d, max = %d\r\n", EventPool::instance().utilization(), EventPool::instance().maxUtilization());
-        mChannelACurrent = mAFloor;
+        recalculate();
-        mChannelBCurrent = mBFloor;
         dump();
-        reset();
         mTicks = 0;
       }
     break;
-#if 0
-  case RSSI_SAMPLE_EVENT:
-    {
-      report(e.rssiSample.channel, e.rssiSample.rssi);
-      uint8_t rssi = getNoiseFloor(e.rssiSample.channel);
-      RadioManager::instance().noiseFloorUpdated(e.rssiSample.channel, rssi);
-    }
-    break;
-#endif
   default:
     break;
   }
 }
 
-#if 0
-void NoiseFloorDetector::processSample(ChannelReadings &window, uint8_t rssi)
-{
-  while ( window.size() >= WINDOW_SIZE )
-    window.pop_back();
-
-  if ( window.empty() )
-    {
-      window.push_back(rssi);
-      return;
-    }
-
-  // Insert the reading at the start if it qualifies
-  for ( ChannelReadings::iterator i = window.begin(); i != window.end(); ++i )
-    {
-      if ( rssi <= *i )
-        {
-          window.insert(i, rssi);
-          break;
-        }
-    }
-
-}
-
-uint8_t NoiseFloorDetector::medianValue(ChannelReadings &window)
-{
-  if ( window.size() < WINDOW_SIZE )
-    return 0xff;
-
-  return window[window.size()/2];
-}
-
-#endif
-
 void NoiseFloorDetector::dump()
 {
   Event *e = EventPool::instance().newEvent(PROPR_NMEA_SENTENCE);
@@ -164,10 +110,19 @@ void NoiseFloorDetector::dump()
   EventQueue::instance().push(e);
 }
 
-void NoiseFloorDetector::reset()
+void NoiseFloorDetector::recalculate()
 {
-  //mChannelASamples.clear();
+  if ( mChannelACurrent == 0xff || mChannelBCurrent == 0xff )
-  //mChannelBSamples.clear();
+    {
+      mChannelACurrent = mAFloor;
+      mChannelBCurrent = mBFloor;
+    }
+  else
+    {
+      mChannelACurrent = (mChannelACurrent + mAFloor) / 2;
+      mChannelBCurrent = (mChannelBCurrent + mBFloor) / 2;
+    }
+
   mAFloor = 0xff;
   mBFloor = 0xff;
 }

latest/Firmware/Src/Receiver.cpp

@@ -150,16 +150,24 @@ void Receiver::onBitClock()
     }
 #if ENABLE_TX
   /**
-   * This trick ensures that we only sample RSSI every 17 time slots and never in the
+   * This trick ensures that we only sample RSSI every N time slots and never in the
    * same time slot for both ICs, so we don't conduct long SPI operations on consecutive
    * interrupt handlers that might exceed the bit clock period. There is no reason for RSSI
    * collection to have a high duty cycle anyway, it just serves to establish the noise floor.
    */
-  else if ( mTimeSlot != 0xffffffff && mSlotBitNumber != 0xffff &&
+#if FULL_RSSI_SAMPLING
-      mTimeSlot % 17 == mChipID && mSlotBitNumber == CCA_SLOT_BIT - 1 )
+  else if ( mTimeSlot != 0xffffffff && mSlotBitNumber != 0xffff && mSlotBitNumber == CCA_SLOT_BIT )
     {
-      reportRSSI();
+      mRXPacket->setRSSI(reportRSSI());
     }
+#else
+  else if ( mTimeSlot != 0xffffffff && mSlotBitNumber != 0xffff &&
+      mTimeSlot % 17 == mChipID &&
+      mSlotBitNumber == CCA_SLOT_BIT - 1 )
+    {
+      mRXPacket->setRSSI(reportRSSI());
+    }
+#endif
 #endif
 
   //bsp_signal_low();

latest/Firmware/Src/TXPacket.cpp

@@ -73,7 +73,7 @@ time_t TXPacket::timestamp()
 
 void TXPacket::setMessageType(const char *t)
 {
-  strncpy(mMessageType, t, sizeof mMessageType);
+  strlcpy(mMessageType, t, sizeof mMessageType);
 }
 
 bool TXPacket::isTestPacket()

latest/Firmware/Src/Transceiver.cpp

@@ -217,7 +217,12 @@ void Transceiver::onBitClock()
         }
       else if ( mUTC && mSlotBitNumber == CCA_SLOT_BIT && mTXPacket->channel() == mChannel )
         {
+#if FULL_RSSI_SAMPLING
+          // It has already been sampled during Receiver::onBitClock();
+          int rssi = mRXPacket->rssi();
+#else
           int rssi = readRSSI();
+#endif
           int nf = NoiseFloorDetector::instance().getNoiseFloor(AIS_CHANNELS[mChannel].designation);
           if ( rssi <= nf + TX_CCA_HEADROOM )
             {

latest/Firmware/Src/bsp/bsp_9_3.cpp

@@ -58,7 +58,7 @@ static const GPIO __gpios[] = {
     {TX_DISABLE_PORT, {TX_DISABLE_PIN, GPIO_MODE_INPUT, GPIO_PULLUP, GPIO_SPEED_LOW, 0}, GPIO_PIN_SET},
     {CS2_PORT, {CS2_PIN, GPIO_MODE_OUTPUT_PP, GPIO_NOPULL, GPIO_SPEED_HIGH, 0}, GPIO_PIN_SET},
     {RX_EVT_PORT, {RX_EVT_PIN, GPIO_MODE_OUTPUT_PP, GPIO_NOPULL, GPIO_SPEED_LOW, 0}, GPIO_PIN_RESET},
-    {GNSS_1PPS_PORT, {GNSS_1PPS_PIN, GPIO_MODE_IT_FALLING, GPIO_PULLUP, GPIO_SPEED_LOW, 0}, GPIO_PIN_RESET},
+    {GNSS_1PPS_PORT, {GNSS_1PPS_PIN, GPIO_MODE_IT_FALLING, GPIO_NOPULL, GPIO_SPEED_LOW, 0}, GPIO_PIN_RESET},
     {GNSS_NMEA_RX_PORT, {GNSS_NMEA_RX_PIN, GPIO_MODE_AF_PP, GPIO_PULLUP, GPIO_SPEED_LOW, GPIO_AF7_USART2}, GPIO_PIN_RESET},
     {CS1_PORT, {CS1_PIN, GPIO_MODE_OUTPUT_PP, GPIO_NOPULL, GPIO_SPEED_HIGH, 0}, GPIO_PIN_SET},
     {SCK_PORT, {SCK_PIN, GPIO_MODE_AF_PP, GPIO_NOPULL, GPIO_SPEED_HIGH, GPIO_AF5_SPI1}, GPIO_PIN_SET},
@@ -384,7 +384,6 @@ void bsp_gnss_on()
 void bsp_gnss_off()
 {
   HAL_GPIO_WritePin(GNSS_EN_PORT, GNSS_EN_PIN, GPIO_PIN_RESET);
-  HAL_Delay(10);
 }
 
 
@@ -541,6 +540,8 @@ void bsp_enter_dfu()
   // Cut off the GPS signals immediately to prevent its UART from transmitting and hijacking the bootloader upon reset
   bsp_gnss_off();
 
+  HAL_Delay(1000);
+
   // This flag simply tells main() to jump to the ROM bootloader immediately upon reset, before initializing anything
   *(uint32_t*)DFU_FLAG_ADDRESS = DFU_FLAG_MAGIC;