Separate RTCM counts and checking from NtripServer

Fix for #292. There are four ways RTCM can be transmitted: Bluetooth, WiFi NTRIP Server, ESP-Now, and external radio. The RTCM count is now processed based on timeout of RTCM bytes received over I2C. RTCM is also passed to NtripServer and ESPNow when enabled. checkRtcmMessage() (originally part of NTRIP Server) has been separated but is non-fucntional.

Author: nseidle

Firmware/RTK_Surveyor/Base.ino

@@ -227,7 +227,34 @@ bool startFixedBase()
 //Useful for passing the RTCM correction data to a radio, Ntrip broadcaster, etc.
 void SFE_UBLOX_GNSS::processRTCM(uint8_t incoming)
 {
-  ntripServerProcessRTCM(incoming);
+  //Check for too many digits
+  if (settings.enableResetDisplay == true)
+  {
+    if (rtcmPacketsSent > 99) rtcmPacketsSent = 1; //Trim to two digits to avoid overlap
+  }
+  else if (logIncreasing == true)
+  {
+    if (rtcmPacketsSent > 999) rtcmPacketsSent = 1; //Trim to three digits to avoid log icon
+  }
+  else
+  {
+    if (rtcmPacketsSent > 9999) rtcmPacketsSent = 1;
+  }
 
-  espnowProcessRTCM(incoming);
+  //Determine if we should check this byte with the RTCM checker or simply pass it along
+  bool passAlongIncomingByte = true;
+
+  if (settings.enableRtcmMessageChecking == true)
+    passAlongIncomingByte &= checkRtcmMessage(incoming);
+
+  //Give this byte to the various possible transmission methods
+  if (passAlongIncomingByte)
+  {
+    rtcmLastReceived = millis();
+    rtcmBytesSent++;
+    
+    ntripServerProcessRTCM(incoming);
+
+    espnowProcessRTCM(incoming);
+  }
 }

Firmware/RTK_Surveyor/Display.ino

@@ -1456,10 +1456,10 @@ void printTextwithKerning(const char *newText, uint8_t xPos, uint8_t yPos, uint8
 void paintRTCM()
 {
   int yPos = 17;
-  if (bluetoothGetState() != BT_OFF)
-    printTextCenter("Xmitting", yPos, QW_FONT_8X16, 1, false);  //text, y, font type, kerning, inverted
-  else
+  if (ntripServerState == NTRIP_SERVER_CASTING)
     printTextCenter("Casting", yPos, QW_FONT_8X16, 1, false);  //text, y, font type, kerning, inverted
+  else
+    printTextCenter("Xmitting", yPos, QW_FONT_8X16, 1, false);  //text, y, font type, kerning, inverted
 
   oled.setCursor(0, 39); //x, y
   oled.setFont(QW_FONT_5X7);

Firmware/RTK_Surveyor/NVM.ino

@@ -266,7 +266,7 @@ void recordSystemSettingsToFile(File * settingsFile)
     settingsFile->println(tempString);
   }
   settingsFile->printf("%s=%d\n\r", "espnowPeerCount", settings.espnowPeerCount);
-  settingsFile->printf("%s=%d\n\r", "enableNtripServerMessageParsing", settings.enableNtripServerMessageParsing);
+  settingsFile->printf("%s=%d\n\r", "enableRtcmMessageChecking", settings.enableRtcmMessageChecking);
   settingsFile->printf("%s=%d\n\r", "bluetoothRadioType", settings.bluetoothRadioType);
 
   //Record constellation settings
@@ -874,8 +874,8 @@ bool parseLine(char* str, Settings *settings)
     settings->radioType = (RadioType_e)d;
   else if (strcmp(settingName, "espnowPeerCount") == 0)
     settings->espnowPeerCount = d;
-  else if (strcmp(settingName, "enableNtripServerMessageParsing") == 0)
-    settings->enableNtripServerMessageParsing = d;
+  else if (strcmp(settingName, "enableRtcmMessageChecking") == 0)
+    settings->enableRtcmMessageChecking = d;
   else if (strcmp(settingName, "radioType") == 0)
     settings->radioType = (RadioType_e)d;
   else if (strcmp(settingName, "bluetoothRadioType") == 0)

Firmware/RTK_Surveyor/NtripServer.ino

@@ -156,123 +156,6 @@ void ntripServerResponse(char * response, size_t maxLength)
   *response = '\0';
 }
 
-static byte ntripServerCrcState = RTCM_TRANSPORT_STATE_WAIT_FOR_PREAMBLE_D3;
-
-//Parse the RTCM transport data
-bool ntripServerRtcmMessage(uint8_t data)
-{
-  static uint16_t bytesRemaining;
-  static uint16_t length;
-  static uint16_t message;
-  static bool sendMessage = false;
-
-  //
-  //    RTCM Standard 10403.2 - Chapter 4, Transport Layer
-  //
-  //    |<------------- 3 bytes ------------>|<----- length ----->|<- 3 bytes ->|
-  //    |                                    |                    |             |
-  //    +----------+--------+----------------+---------+----------+-------------+
-  //    | Preamble |  Fill  | Message Length | Message |   Fill   |   CRC-24Q   |
-  //    |  8 bits  | 6 bits |    10 bits     |  n-bits | 0-7 bits |   24 bits   |
-  //    |   0xd3   | 000000 |   (in bytes)   |         |   zeros  |             |
-  //    +----------+--------+----------------+---------+----------+-------------+
-  //    |                                                                       |
-  //    |<-------------------------------- CRC -------------------------------->|
-  //
-
-  switch (ntripServerCrcState)
-  {
-    //Read the upper two bits of the length
-    case RTCM_TRANSPORT_STATE_READ_LENGTH_1:
-      if (!(data & 3))
-      {
-        length = data << 8;
-        ntripServerCrcState = RTCM_TRANSPORT_STATE_READ_LENGTH_2;
-        break;
-      }
-
-      //Wait for the preamble byte
-      ntripServerCrcState = RTCM_TRANSPORT_STATE_WAIT_FOR_PREAMBLE_D3;
-
-    //Fall through
-    //     |
-    //     |
-    //     V
-
-    //Wait for the preamble byte (0xd3)
-    case RTCM_TRANSPORT_STATE_WAIT_FOR_PREAMBLE_D3:
-      sendMessage = false;
-      if (data == 0xd3)
-      {
-        ntripServerCrcState = RTCM_TRANSPORT_STATE_READ_LENGTH_1;
-        sendMessage = (ntripServerState == NTRIP_SERVER_CASTING);
-      }
-      break;
-
-    //Read the lower 8 bits of the length
-    case RTCM_TRANSPORT_STATE_READ_LENGTH_2:
-      length |= data;
-      bytesRemaining = length;
-      ntripServerCrcState = RTCM_TRANSPORT_STATE_READ_MESSAGE_1;
-      break;
-
-    //Read the upper 8 bits of the message number
-    case RTCM_TRANSPORT_STATE_READ_MESSAGE_1:
-      message = data << 4;
-      bytesRemaining -= 1;
-      ntripServerCrcState = RTCM_TRANSPORT_STATE_READ_MESSAGE_2;
-      break;
-
-    //Read the lower 4 bits of the message number
-    case RTCM_TRANSPORT_STATE_READ_MESSAGE_2:
-      message |= data >> 4;
-      bytesRemaining -= 1;
-      ntripServerCrcState = RTCM_TRANSPORT_STATE_READ_DATA;
-      break;
-
-    //Read the rest of the message
-    case RTCM_TRANSPORT_STATE_READ_DATA:
-      bytesRemaining -= 1;
-      if (bytesRemaining <= 0)
-        ntripServerCrcState = RTCM_TRANSPORT_STATE_READ_CRC_1;
-      break;
-
-    //Read the upper 8 bits of the CRC
-    case RTCM_TRANSPORT_STATE_READ_CRC_1:
-      ntripServerCrcState = RTCM_TRANSPORT_STATE_READ_CRC_2;
-      break;
-
-    //Read the middle 8 bits of the CRC
-    case RTCM_TRANSPORT_STATE_READ_CRC_2:
-      ntripServerCrcState = RTCM_TRANSPORT_STATE_READ_CRC_3;
-      break;
-
-    //Read the lower 8 bits of the CRC
-    case RTCM_TRANSPORT_STATE_READ_CRC_3:
-      ntripServerCrcState = RTCM_TRANSPORT_STATE_CHECK_CRC;
-      break;
-  }
-
-  //Check the CRC
-  if (ntripServerCrcState == RTCM_TRANSPORT_STATE_CHECK_CRC)
-  {
-    ntripServerCrcState = RTCM_TRANSPORT_STATE_WAIT_FOR_PREAMBLE_D3;
-
-    //Account for this message
-    rtcmPacketsSent++;
-
-    //Display the RTCM message header
-    if (settings.enablePrintNtripServerRtcm && (!inMainMenu))
-    {
-      printTimeStamp();
-      Serial.printf ("    Tx RTCM %d, %2d bytes\r\n", message, 3 + length + 3);
-    }
-  }
-
-  //Let the upper layer know if this message should be sent
-  return sendMessage && (ntripServerState == NTRIP_SERVER_CASTING);
-}
-
 //Update the state of the NTRIP server state machine
 void ntripServerSetState(byte newState)
 {
@@ -319,75 +202,52 @@ void ntripServerSetState(byte newState)
 //This function gets called as each RTCM byte comes in
 void ntripServerProcessRTCM(uint8_t incoming)
 {
-  //Check for too many digits
-  if (settings.enableResetDisplay == true)
-  {
-    if (rtcmPacketsSent > 99) rtcmPacketsSent = 1; //Trim to two digits to avoid overlap
-  }
-  else if (logIncreasing == true)
-  {
-    if (rtcmPacketsSent > 999) rtcmPacketsSent = 1; //Trim to three digits to avoid log icon
-  }
-  else
-  {
-    if (rtcmPacketsSent > 9999) rtcmPacketsSent = 1;
-  }
-
 #ifdef  COMPILE_WIFI
-  uint32_t currentMilliseconds;
-  static uint32_t previousMilliseconds = 0;
 
-  if (online.rtc && (ntripServerState == NTRIP_SERVER_CASTING))
+  if (ntripServerState == NTRIP_SERVER_CASTING)
   {
-    //Timestamp the RTCM messages
-    currentMilliseconds = millis();
-    if (settings.enablePrintNtripServerRtcm
-        && (!settings.enableNtripServerMessageParsing)
-        && (!inMainMenu)
-        && ((currentMilliseconds - previousMilliseconds) > 5))
-    {
-      printTimeStamp();
-      //         1         2         3
-      //123456789012345678901234567890
-      //YYYY-mm-dd HH:MM:SS.xxxrn0
-      struct tm timeinfo = rtc.getTimeStruct();
-      char timestamp[30];
-      strftime(timestamp, sizeof(timestamp), "%Y-%m-%d %H:%M:%S", &timeinfo);
-      Serial.printf("    Tx RTCM: %s.%03ld\r\n", timestamp, rtc.getMillis());
-    }
-    previousMilliseconds = currentMilliseconds;
-
-    //Pass this message to the RTCM checker
-    bool passAlongIncomingByte = true;
-
-    //Check this byte with RTCM checker if enabled
-    if (settings.enableNtripServerMessageParsing == true)
-      passAlongIncomingByte &= ntripServerRtcmMessage(incoming);
-    else
+    //Generate and print timestamp if needed
+    uint32_t currentMilliseconds;
+    static uint32_t previousMilliseconds = 0;
+    if (online.rtc)
     {
-      //If we have not gotten new RTCM bytes for a period of time, assume end of frame
-      if (millis() - ntripServerTimer > 100 && ntripServerBytesSent > 0)
+      //Timestamp the RTCM messages
+      currentMilliseconds = millis();
+      if (settings.enablePrintNtripServerRtcm
+          && (!settings.enableRtcmMessageChecking)
+          && (!inMainMenu)
+          && ((currentMilliseconds - previousMilliseconds) > 5))
       {
-        if(!inMainMenu) log_d("NTRIP Server transmitted %d RTCM bytes to Caster", ntripServerBytesSent);
-        ntripServerBytesSent = 0;
-        rtcmPacketsSent++; //If not checking RTCM CRC, count based on timeout
+        printTimeStamp();
+        //         1         2         3
+        //123456789012345678901234567890
+        //YYYY-mm-dd HH:MM:SS.xxxrn0
+        struct tm timeinfo = rtc.getTimeStruct();
+        char timestamp[30];
+        strftime(timestamp, sizeof(timestamp), "%Y-%m-%d %H:%M:%S", &timeinfo);
+        Serial.printf("    Tx RTCM: %s.%03ld\r\n", timestamp, rtc.getMillis());
       }
+      previousMilliseconds = currentMilliseconds;
     }
 
-    if (passAlongIncomingByte)
+    //If we have not gotten new RTCM bytes for a period of time, assume end of frame
+    if (millis() - ntripServerTimer > 100 && ntripServerBytesSent > 0)
     {
-      ntripServer->write(incoming); //Send this byte to socket
-      ntripServerBytesSent++;
-      ntripServerTimer = millis();
-      wifiOutgoingRTCM = true;
+      if (!inMainMenu) log_d("NTRIP Server transmitted %d RTCM bytes to Caster", ntripServerBytesSent);
+      ntripServerBytesSent = 0;
     }
+
+    ntripServer->write(incoming); //Send this byte to socket
+    ntripServerBytesSent++;
+    ntripServerTimer = millis();
+    wifiOutgoingRTCM = true;
   }
 
   //Indicate that the GNSS is providing correction data
   else if (ntripServerState == NTRIP_SERVER_WAIT_GNSS_DATA)
   {
     ntripServerSetState(NTRIP_SERVER_CONNECTING);
-    ntripServerCrcState = RTCM_TRANSPORT_STATE_WAIT_FOR_PREAMBLE_D3;
+    rtcmParsingState = RTCM_TRANSPORT_STATE_WAIT_FOR_PREAMBLE_D3;
   }
 #endif  //COMPILE_WIFI
 }

Firmware/RTK_Surveyor/RTK_Surveyor.ino

@@ -401,7 +401,9 @@ uint64_t lastLogSize = 0;
 bool logIncreasing = false; //Goes true when log file is greater than lastLogSize
 bool reuseLastLog = false; //Goes true if we have a reset due to software (rather than POR)
 
-uint32_t rtcmPacketsSent = 0; //Used to count RTCM packets sent via processRTCM()
+uint16_t rtcmPacketsSent = 0; //Used to count RTCM packets sent via processRTCM()
+uint32_t rtcmBytesSent = 0;
+uint32_t rtcmLastReceived = 0;
 
 uint32_t maxSurveyInWait_s = 60L * 15L; //Re-start survey-in after X seconds
 
@@ -468,6 +470,8 @@ bool wifiOutgoingRTCM = false;
 bool espnowIncomingRTCM = false;
 bool espnowOutgoingRTCM = false;
 
+static byte rtcmParsingState = RTCM_TRANSPORT_STATE_WAIT_FOR_PREAMBLE_D3;
+
 //-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
 /*
                      +---------------------------------------+      +----------+
@@ -840,6 +844,13 @@ void updateRTC()
 //Internal ESP NOW radio - Use the ESP32 to directly transmit/receive RTCM over 2.4GHz (no WiFi needed)
 void updateRadio()
 {
+  //If we have not gotten new RTCM bytes for a period of time, assume end of frame
+  if (millis() - rtcmLastReceived > 50 && rtcmBytesSent > 0)
+  {
+    rtcmBytesSent = 0;
+    rtcmPacketsSent++; //If not checking RTCM CRC, count based on timeout
+  }
+
 #ifdef COMPILE_ESPNOW
   if (settings.radioType == RADIO_ESPNOW)
   {
@@ -849,11 +860,9 @@ void updateRadio()
       //then we've reached the end of the RTCM stream. Send partial buffer.
       if (espnowOutgoingSpot > 0 && (millis() - espnowLastAdd) > 50)
       {
-        rtcmPacketsSent++; //Assume this is the end of the RTCM frame
-
         esp_now_send(0, (uint8_t *) &espnowOutgoing, espnowOutgoingSpot); //Send partial packet to all peers
-        
-        if(!inMainMenu) log_d("ESPNOW transmitted %d RTCM bytes", espnowBytesSent + espnowOutgoingSpot);
+
+        if (!inMainMenu) log_d("ESPNOW transmitted %d RTCM bytes", espnowBytesSent + espnowOutgoingSpot);
         espnowBytesSent = 0;
         espnowOutgoingSpot = 0; //Reset
       }

Firmware/RTK_Surveyor/menuSystem.ino

@@ -385,8 +385,8 @@ void menuDebug()
     Serial.print("27) Print duplicate states: ");
     Serial.printf("%s\r\n", settings.enablePrintDuplicateStates ? "Enabled" : "Disabled");
 
-    Serial.print("28) NTRIP server message parser: ");
-    Serial.printf("%s\r\n", settings.enableNtripServerMessageParsing ? "Enabled" : "Disabled");
+    Serial.print("28) RTCM message checking: ");
+    Serial.printf("%s\r\n", settings.enableRtcmMessageChecking ? "Enabled" : "Disabled");
 
     Serial.println("t) Enter Test Screen");
 
@@ -568,7 +568,7 @@ void menuDebug()
       }
       else if (incoming == 28)
       {
-        settings.enableNtripServerMessageParsing ^= 1;
+        settings.enableRtcmMessageChecking ^= 1;
       }
       else
         printUnknown(incoming);

Firmware/RTK_Surveyor/settings.h

@@ -472,7 +472,7 @@ typedef struct {
   RadioType_e radioType = RADIO_EXTERNAL;
   uint8_t espnowPeers[5][6]; //Max of 5 peers. Contains the MAC addresses (6 bytes) of paired units
   uint8_t espnowPeerCount;
-  bool enableNtripServerMessageParsing = false;
+  bool enableRtcmMessageChecking = false;
   BluetoothRadioType_e bluetoothRadioType = BLUETOOTH_RADIO_SPP;
 } Settings;
 Settings settings;