Merge pull request #92 from sparkfun/AddGPGGAToNTRIP

Add NTRIP Client with GGA example

examples/ZED-F9P/Example14_NTRIPServer/Example14_NTRIPServer.ino

@@ -1,7 +1,5 @@
 /*
-  Note: compiles OK with v2.0 but is currently untested
-  
-  Use ESP32 WiFi to push RTCM data to RTK2Go (caster) as a Server
+  Use ESP32 WiFi to push RTCM data to RTK2Go (Caster) as a Server
   By: SparkFun Electronics / Nathan Seidle
   Date: December 14th, 2020
   License: MIT. See license file for more information but you can
@@ -33,25 +31,20 @@
 
 #include <WiFi.h>
 #include "secrets.h"
-WiFiClient client;
+WiFiClient ntripCaster;
 
-#include <Wire.h> //Needed for I2C to GNSS
+#include <Wire.h>
 #include <SparkFun_u-blox_GNSS_Arduino_Library.h> //http://librarymanager/All#SparkFun_u-blox_GNSS
 SFE_UBLOX_GNSS myGNSS;
 
-//Basic Connection settings to RTK2Go NTRIP Caster - See secrets for mount specific credentials
+//Global Variables
 //=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
-const uint16_t casterPort = 2101;
-const char * casterHost = "rtk2go.com";
-const char * ntrip_server_name = "SparkFun_RTK_Surveyor";
-
 long lastSentRTCM_ms = 0;           //Time of last data pushed to socket
 int maxTimeBeforeHangup_ms = 10000; //If we fail to get a complete RTCM frame after 10s, then disconnect from caster
 
 uint32_t serverBytesSent = 0; //Just a running total
-//=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
-
 long lastReport_ms = 0;       //Time of last report of bytes sent
+//=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
 
 void setup()
 {
@@ -73,7 +66,8 @@ void setup()
 
   Serial.print("Connecting to local WiFi");
   WiFi.begin(ssid, password);
-  while (WiFi.status() != WL_CONNECTED) {
+  while (WiFi.status() != WL_CONNECTED)
+  {
     delay(500);
     Serial.print(".");
   }
@@ -98,7 +92,8 @@ void setup()
   if (response == false)
   {
     Serial.println(F("Failed to disable NMEA. Freezing..."));
-    while (1);
+    while (1)
+      ;
   }
   else
     Serial.println(F("NMEA disabled"));
@@ -114,7 +109,8 @@ void setup()
   if (response == false)
   {
     Serial.println(F("Failed to enable RTCM. Freezing..."));
-    while (1);
+    while (1)
+      ;
   }
   else
     Serial.println(F("RTCM sentences enabled"));
@@ -129,63 +125,72 @@ void setup()
   if (response == false)
   {
     Serial.println(F("Failed to enter static position. Freezing..."));
-    while (1);
+    while (1)
+      ;
   }
   else
     Serial.println(F("Static position set"));
 
-  //You could instead do a survey-in but it takes much longer to start generating RTCM data. See Example4_BaseWithLCD
+  //Alternatively to setting a static position, you could do a survey-in
+  //but it takes much longer to start generating RTCM data. See Example4_BaseWithLCD
   //myGNSS.enableSurveyMode(60, 5.000); //Enable Survey in, 60 seconds, 5.0m
 
-  if (myGNSS.saveConfiguration() == false) //Save the current settings to flash and BBR
-    Serial.println(F("Module failed to save."));
+  //If you were setting up a full GNSS station, you would want to save these settings.
+  //Because setting an incorrect static position will disable the ability to get a lock, we will skip saving during this example
+  //if (myGNSS.saveConfiguration() == false) //Save the current settings to flash and BBR
+  //  Serial.println(F("Module failed to save"));
 
   Serial.println(F("Module configuration complete"));
 }
 
 void loop()
 {
-  if (Serial.available()) beginServing();
+  if (Serial.available())
+    beginServing();
 
-  Serial.println(F("Press any key to start serving."));
+  Serial.println(F("Press any key to start serving"));
 
   delay(1000);
 }
 
 void beginServing()
 {
-  Serial.println("Xmit to RTK2Go. Press any key to stop");
+  Serial.println("Begin transmitting to caster. Press any key to stop");
   delay(10); //Wait for any serial to arrive
-  while (Serial.available()) Serial.read(); //Flush
+  while (Serial.available())
+    Serial.read(); //Flush
 
   while (Serial.available() == 0)
   {
     //Connect if we are not already
-    if (client.connected() == false)
+    if (ntripCaster.connected() == false)
     {
       Serial.printf("Opening socket to %s\n", casterHost);
 
-      if (client.connect(casterHost, casterPort) == true) //Attempt connection
+      if (ntripCaster.connect(casterHost, casterPort) == true) //Attempt connection
       {
         Serial.printf("Connected to %s:%d\n", casterHost, casterPort);
 
         const int SERVER_BUFFER_SIZE = 512;
-        char serverBuffer[SERVER_BUFFER_SIZE];
+        char serverRequest[SERVER_BUFFER_SIZE];
 
-        snprintf(serverBuffer, SERVER_BUFFER_SIZE, "SOURCE %s /%s\r\nSource-Agent: NTRIP %s/%s\r\n\r\n",
-                 mntpnt_pw, mntpnt, ntrip_server_name, "App Version 1.0");
+        snprintf(serverRequest,
+                 SERVER_BUFFER_SIZE,
+                 "SOURCE %s /%s\r\nSource-Agent: NTRIP SparkFun u-blox Server v1.0\r\n\r\n",
+                 mountPointPW, mountPoint);
 
-        Serial.printf("Sending credentials:\n%s\n", serverBuffer);
-        client.write(serverBuffer, strlen(serverBuffer));
+        Serial.println(F("Sending server request:"));
+        Serial.println(serverRequest);
+        ntripCaster.write(serverRequest, strlen(serverRequest));
 
         //Wait for response
         unsigned long timeout = millis();
-        while (client.available() == 0)
+        while (ntripCaster.available() == 0)
         {
           if (millis() - timeout > 5000)
           {
-            Serial.println(">>> Client Timeout !");
-            client.stop();
+            Serial.println("Caster timed out!");
+            ntripCaster.stop();
             return;
           }
           delay(10);
@@ -195,30 +200,34 @@ void beginServing()
         bool connectionSuccess = false;
         char response[512];
         int responseSpot = 0;
-        while (client.available())
+        while (ntripCaster.available())
         {
-          response[responseSpot++] = client.read();
+          response[responseSpot++] = ntripCaster.read();
           if (strstr(response, "200") > 0) //Look for 'ICY 200 OK'
             connectionSuccess = true;
-          if (responseSpot == 512 - 1) break;
+          if (responseSpot == 512 - 1)
+            break;
         }
         response[responseSpot] = '\0';
 
         if (connectionSuccess == false)
         {
-          Serial.printf("Failed to connect to RTK2Go: %s", response);
+          Serial.printf("Failed to connect to Caster: %s", response);
+          return;
         }
       } //End attempt to connect
       else
       {
         Serial.println("Connection to host failed");
+        return;
       }
     } //End connected == false
 
-    if (client.connected() == true)
+    if (ntripCaster.connected() == true)
     {
       delay(10);
-      while (Serial.available()) Serial.read(); //Flush any endlines or carriage returns
+      while (Serial.available())
+        Serial.read(); //Flush any endlines or carriage returns
 
       lastReport_ms = millis();
       lastSentRTCM_ms = millis();
@@ -226,7 +235,8 @@ void beginServing()
       //This is the main sending loop. We scan for new ublox data but processRTCM() is where the data actually gets sent out.
       while (1)
       {
-        if (Serial.available()) break;
+        if (Serial.available())
+          break;
 
         myGNSS.checkUblox(); //See if new data is available. Process bytes as they come in.
 
@@ -236,7 +246,7 @@ void beginServing()
         if (millis() - lastSentRTCM_ms > maxTimeBeforeHangup_ms)
         {
           Serial.println("RTCM timeout. Disconnecting...");
-          client.stop();
+          ntripCaster.stop();
           return;
         }
 
@@ -256,10 +266,11 @@ void beginServing()
 
   Serial.println("User pressed a key");
   Serial.println("Disconnecting...");
-  client.stop();
+  ntripCaster.stop();
 
   delay(10);
-  while (Serial.available()) Serial.read(); //Flush any endlines or carriage returns
+  while (Serial.available())
+    Serial.read(); //Flush any endlines or carriage returns
 }
 
 //This function gets called from the SparkFun u-blox Arduino Library.
@@ -267,9 +278,9 @@ void beginServing()
 //Useful for passing the RTCM correction data to a radio, Ntrip broadcaster, etc.
 void SFE_UBLOX_GNSS::processRTCM(uint8_t incoming)
 {
-  if (client.connected() == true)
+  if (ntripCaster.connected() == true)
   {
-    client.write(incoming); //Send this byte to socket
+    ntripCaster.write(incoming); //Send this byte to socket
     serverBytesSent++;
     lastSentRTCM_ms = millis();
   }

examples/ZED-F9P/Example14_NTRIPServer/secrets.h

@@ -1,7 +1,15 @@
 //Your WiFi credentials
-const char* ssid = "TRex";
-const char* password =  "hasBigTeeth";
+const char *ssid = "TRex";
+const char *password = "hasBigTeeth";
 
-//Your RTK2GO mount point credentials
-const char* mntpnt_pw = "WR5wRo4H";
-const char* mntpnt = "bldr_dwntwn2";
+//RTK2Go works well and is free
+const char casterHost[] = "rtk2go.com";
+const uint16_t casterPort = 2101;
+const char mountPoint[] = "bldr_dwntwn2"; //The mount point you want to push data to
+const char mountPointPW[] = "WR5wRo4H";
+
+//Emlid Caster also works well and is free
+//const char casterHost[] = "caster.emlid.com";
+//const uint16_t casterPort = 2101;
+//const char mountPoint[] = "MP1979d"; //The mount point you want to push data to
+//const char mountPointPW[] = "296ynq";

examples/ZED-F9P/Example15_NTRIPClient/Example15_NTRIPClient.ino

@@ -16,6 +16,9 @@
   This is a proof of concept to show how to connect to a caster via HTTP. Using WiFi for a rover
   is generally a bad idea because of limited WiFi range in the field.
 
+  For more information about NTRIP Clients and the differences between Rev1 and Rev2 of the protocol
+  please see: https://www.use-snip.com/kb/knowledge-base/ntrip-rev1-versus-rev2-formats/
+
   Feel like supporting open source hardware?
   Buy a board from SparkFun!
   ZED-F9P RTK2: https://www.sparkfun.com/products/16481
@@ -50,7 +53,7 @@ int maxTimeBeforeHangup_ms = 10000; //If we fail to get a complete RTCM frame af
 void setup()
 {
   Serial.begin(115200);
-  Serial.println("NTRIP testing");
+  Serial.println(F("NTRIP testing"));
 
   Wire.begin(); //Start I2C
 
@@ -66,15 +69,15 @@ void setup()
 
   myGNSS.setNavigationFrequency(1); //Set output in Hz.
 
-  Serial.print("Connecting to local WiFi");
+  Serial.print(F("Connecting to local WiFi"));
   WiFi.begin(ssid, password);
   while (WiFi.status() != WL_CONNECTED) {
     delay(500);
-    Serial.print(".");
+    Serial.print(F("."));
   }
   Serial.println();
 
-  Serial.print("WiFi connected with IP: ");
+  Serial.print(F("WiFi connected with IP: "));
   Serial.println(WiFi.localIP());
 
   while (Serial.available()) Serial.read();
@@ -82,7 +85,11 @@ void setup()
 
 void loop()
 {
-  if (Serial.available()) beginClient();
+  if (Serial.available())
+  {
+    beginClient();
+    while (Serial.available()) Serial.read(); //Empty buffer of any newline chars
+  }
 
   Serial.println(F("Press any key to start NTRIP Client."));
 
@@ -95,36 +102,37 @@ void beginClient()
   WiFiClient ntripClient;
   long rtcmCount = 0;
 
-  Serial.println("Subscribing to Caster. Press key to stop");
+  Serial.println(F("Subscribing to Caster. Press key to stop"));
   delay(10); //Wait for any serial to arrive
   while (Serial.available()) Serial.read(); //Flush
 
   while (Serial.available() == 0)
   {
-    //Connect if we are not already
+    //Connect if we are not already. Limit to 5s between attempts.
     if (ntripClient.connected() == false)
     {
-      Serial.print("Opening socket to");
+      Serial.print(F("Opening socket to "));
       Serial.println(casterHost);
 
       if (ntripClient.connect(casterHost, casterPort) == false) //Attempt connection
       {
-        Serial.println("Connection to caster failed");
+        Serial.println(F("Connection to caster failed"));
+        return;
       }
       else
       {
-        Serial.print("Connected to ");
+        Serial.print(F("Connected to "));
         Serial.print(casterHost);
-        Serial.print(": ");
+        Serial.print(F(": "));
         Serial.println(casterPort);
 
-        Serial.print("Requesting NTRIP Data from mount point ");
+        Serial.print(F("Requesting NTRIP Data from mount point "));
         Serial.println(mountPoint);
 
         const int SERVER_BUFFER_SIZE  = 512;
         char serverRequest[SERVER_BUFFER_SIZE];
 
-        snprintf(serverRequest, SERVER_BUFFER_SIZE, "GET /%s HTTP/1.0\r\nUser-Agent: SparkFun u-blox NTRIPClient v1.0\r\n",
+        snprintf(serverRequest, SERVER_BUFFER_SIZE, "GET /%s HTTP/1.0\r\nUser-Agent: NTRIP SparkFun u-blox Client v1.0\r\n",
                  mountPoint);
 
         char credentials[512];
@@ -138,7 +146,7 @@ void beginClient()
           char userCredentials[sizeof(casterUser) + sizeof(casterUserPW) + 1]; //The ':' takes up a spot
           snprintf(userCredentials, sizeof(userCredentials), "%s:%s", casterUser, casterUserPW);
 
-          Serial.print("Sending credentials: ");
+          Serial.print(F("Sending credentials: "));
           Serial.println(userCredentials);
 
 #if defined(ARDUINO_ARCH_ESP32)
@@ -158,13 +166,13 @@ void beginClient()
         strncat(serverRequest, credentials, SERVER_BUFFER_SIZE);
         strncat(serverRequest, "\r\n", SERVER_BUFFER_SIZE);
 
-        Serial.print("serverRequest size: ");
+        Serial.print(F("serverRequest size: "));
         Serial.print(strlen(serverRequest));
-        Serial.print(" of ");
+        Serial.print(F(" of "));
         Serial.print(sizeof(serverRequest));
-        Serial.println(" bytes available");
+        Serial.println(F(" bytes available"));
 
-        Serial.println("Sending server request:");
+        Serial.println(F("Sending server request:"));
         Serial.println(serverRequest);
         ntripClient.write(serverRequest, strlen(serverRequest));
 
@@ -174,7 +182,7 @@ void beginClient()
         {
           if (millis() - timeout > 5000)
           {
-            Serial.println("Mountpoint timed out!");
+            Serial.println(F("Caster timed out!"));
             ntripClient.stop();
             return;
           }
@@ -194,23 +202,26 @@ void beginClient()
             connectionSuccess = true;
           if (strstr(response, "401") > 0) //Look for '401 Unauthorized'
           {
-            Serial.println("Hey - your credentials look bad! Check you caster username and password.");
+            Serial.println(F("Hey - your credentials look bad! Check you caster username and password."));
             connectionSuccess = false;
           }
         }
         response[responseSpot] = '\0';
 
+        Serial.print(F("Caster responded with: "));
+        Serial.println(response);
+
         if (connectionSuccess == false)
         {
-          Serial.print("Failed to connect to ");
+          Serial.print(F("Failed to connect to "));
           Serial.print(casterHost);
-          Serial.print(": ");
+          Serial.print(F(": "));
           Serial.println(response);
-          delay(5000); //Don't spam with lots of connection attempts
+          return;
         }
         else
         {
-          Serial.print("Connected to ");
+          Serial.print(F("Connected to "));
           Serial.println(casterHost);
           lastReceivedRTCM_ms = millis(); //Reset timeout
         }
@@ -236,7 +247,7 @@ void beginClient()
 
         //Push RTCM to GNSS module over I2C
         myGNSS.pushRawData(rtcmData, rtcmCount, false);
-        Serial.print("RTCM pushed to ZED: ");
+        Serial.print(F("RTCM pushed to ZED: "));
         Serial.println(rtcmCount);
       }
     }
@@ -244,7 +255,7 @@ void beginClient()
     //Close socket if we don't have new data for 10s
     if (millis() - lastReceivedRTCM_ms > maxTimeBeforeHangup_ms)
     {
-      Serial.println("RTCM timeout. Disconnecting...");
+      Serial.println(F("RTCM timeout. Disconnecting..."));
       if (ntripClient.connected() == true)
         ntripClient.stop();
       return;
@@ -253,9 +264,7 @@ void beginClient()
     delay(10);
   }
 
-  Serial.println("User pressed a key");
-  Serial.println("Disconnecting...");
+  Serial.println(F("User pressed a key"));
+  Serial.println(F("Disconnecting..."));
   ntripClient.stop();
-
-  while (Serial.available()) Serial.read(); //Empty buffer of any newline chars
 }

examples/ZED-F9P/Example16_NTRIPClient_WithGGA/Example16_NTRIPClient_WithGGA.ino

@@ -0,0 +1,403 @@
+/*
+  Use ESP32 WiFi to get RTCM data from RTK2Go (caster) as a Client, and transmit GGA (needed for some Casters)
+  By: SparkFun Electronics / Nathan Seidle
+  Date: November 18th, 2021
+  License: MIT. See license file for more information but you can
+  basically do whatever you want with this code.
+
+  This example shows how to obtain RTCM data from a NTRIP Caster over WiFi
+  and push it over I2C to a ZED-F9x.
+  It's confusing, but the Arduino is acting as a 'client' to a 'caster'. In this case we will
+  use RTK2Go.com as our caster because it is free. See the NTRIPServer example to see how
+  to push RTCM data to the caster.
+
+  The rover's location will be broadcast to the Caster every 10s via GGA setence.
+
+  You will need to have a valid mountpoint available. To see available mountpoints go here: http://rtk2go.com:2101/
+
+  This is a proof of concept to show how to connect to a caster via HTTP.
+
+  For more information about NTRIP Clients and the differences between Rev1 and Rev2 of the protocol
+  please see: https://www.use-snip.com/kb/knowledge-base/ntrip-rev1-versus-rev2-formats/
+
+  "In broad protocol terms, the NTRIP client must first connect (get an HTTP “OK” reply) and only then
+  should it send the sentence.  NTRIP protocol revision 2 (which does not have very broad industry
+  acceptance at this time) does allow sending the sentence in the original header."
+  https://www.use-snip.com/kb/knowledge-base/subtle-issues-with-using-ntrip-client-nmea-183-strings/
+
+  Feel like supporting open source hardware?
+  Buy a board from SparkFun!
+  ZED-F9P RTK2: https://www.sparkfun.com/products/16481
+  RTK Surveyor: https://www.sparkfun.com/products/18443
+  RTK Express: https://www.sparkfun.com/products/18442
+
+  Hardware Connections:
+  Plug a Qwiic cable into the GNSS and a ESP32 Thing Plus
+  If you don't have a platform with a Qwiic connection use the SparkFun Qwiic Breadboard Jumper (https://www.sparkfun.com/products/14425)
+  Open the serial monitor at 115200 baud to see the output
+*/
+#include <WiFi.h>
+#include "secrets.h"
+
+#include <SparkFun_u-blox_GNSS_Arduino_Library.h> //http://librarymanager/All#SparkFun_u-blox_GNSS
+SFE_UBLOX_GNSS myGNSS;
+
+//The ESP32 core has a built in base64 library but not every platform does
+//We'll use an external lib if necessary.
+#if defined(ARDUINO_ARCH_ESP32)
+#include "base64.h" //Built-in ESP32 library
+#else
+#include <Base64.h> //nfriendly library from https://github.com/adamvr/arduino-base64, will work with any platform
+#endif
+
+//Global variables
+//=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
+long lastReceivedRTCM_ms = 0;       //5 RTCM messages take approximately ~300ms to arrive at 115200bps
+int maxTimeBeforeHangup_ms = 10000; //If we fail to get a complete RTCM frame after 10s, then disconnect from caster
+
+bool transmitLocation = true;        //By default we will transmit the units location via GGA sentence.
+int timeBetweenGGAUpdate_ms = 10000; //GGA is required for Rev2 NTRIP casters. Don't transmit but once every 10 seconds
+long lastTransmittedGGA_ms = 0;
+
+//Used for GGA sentence parsing from incoming NMEA
+bool ggaSentenceStarted = false;
+bool ggaSentenceComplete = false;
+bool ggaTransmitComplete = false; //Goes true once we transmit GGA to the caster
+
+char ggaSentence[128] = {0};
+byte ggaSentenceSpot = 0;
+int ggaSentenceEndSpot = 0;
+//=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
+
+void setup()
+{
+  Serial.begin(115200);
+  Serial.println(F("NTRIP testing"));
+
+  Wire.begin(); //Start I2C
+
+  while (myGNSS.begin() == false) //Connect to the Ublox module using Wire port
+  {
+    Serial.println(F("u-blox GPS not detected at default I2C address. Please check wiring. Freezing."));
+    delay(2000);
+    //while (1);
+  }
+  Serial.println(F("u-blox module connected"));
+
+  myGNSS.setI2COutput(COM_TYPE_UBX | COM_TYPE_NMEA);                                //Set the I2C port to output both NMEA and UBX messages
+  myGNSS.setPortInput(COM_PORT_I2C, COM_TYPE_UBX | COM_TYPE_NMEA | COM_TYPE_RTCM3); //Be sure RTCM3 input is enabled. UBX + RTCM3 is not a valid state.
+
+  myGNSS.enableNMEAMessage(UBX_NMEA_GGA, COM_PORT_I2C); //Verify the GGA sentence is enabled
+
+  myGNSS.setNavigationFrequency(1); //Set output in Hz.
+
+  Serial.print(F("Connecting to local WiFi"));
+  WiFi.begin(ssid, password);
+  while (WiFi.status() != WL_CONNECTED)
+  {
+    delay(500);
+    Serial.print(F("."));
+  }
+  Serial.println();
+
+  Serial.print(F("WiFi connected with IP: "));
+  Serial.println(WiFi.localIP());
+
+  while (Serial.available())
+    Serial.read();
+}
+
+void loop()
+{
+  if (Serial.available())
+  {
+    beginClient();
+    while (Serial.available())
+      Serial.read(); //Empty buffer of any newline chars
+  }
+
+  Serial.println(F("Press any key to start NTRIP Client."));
+
+  delay(1000);
+}
+
+//Connect to NTRIP Caster, receive RTCM, and push to ZED module over I2C
+void beginClient()
+{
+  WiFiClient ntripClient;
+  long rtcmCount = 0;
+
+  Serial.println(F("Subscribing to Caster. Press key to stop"));
+  delay(10); //Wait for any serial to arrive
+  while (Serial.available())
+    Serial.read(); //Flush
+
+  while (Serial.available() == 0)
+  {
+    myGNSS.checkUblox();
+
+    //Connect if we are not already. Limit to 5s between attempts.
+    if (ntripClient.connected() == false)
+    {
+      Serial.print(F("Opening socket to "));
+      Serial.println(casterHost);
+
+      if (ntripClient.connect(casterHost, casterPort) == false) //Attempt connection
+      {
+        Serial.println(F("Connection to caster failed"));
+        return;
+      }
+      else
+      {
+        Serial.print(F("Connected to "));
+        Serial.print(casterHost);
+        Serial.print(F(": "));
+        Serial.println(casterPort);
+
+        Serial.print(F("Requesting NTRIP Data from mount point "));
+        Serial.println(mountPoint);
+
+        const int SERVER_BUFFER_SIZE = 512;
+        char serverRequest[SERVER_BUFFER_SIZE];
+
+        snprintf(serverRequest,
+                 SERVER_BUFFER_SIZE,
+                 "GET /%s HTTP/1.0\r\nUser-Agent: NTRIP SparkFun u-blox Client v1.0\r\n",
+                 mountPoint);
+
+        char credentials[512];
+        if (strlen(casterUser) == 0)
+        {
+          strncpy(credentials, "Accept: */*\r\nConnection: close\r\n", sizeof(credentials));
+        }
+        else
+        {
+          //Pass base64 encoded user:pw
+          char userCredentials[sizeof(casterUser) + sizeof(casterUserPW) + 1]; //The ':' takes up a spot
+          snprintf(userCredentials, sizeof(userCredentials), "%s:%s", casterUser, casterUserPW);
+
+          Serial.print(F("Sending credentials: "));
+          Serial.println(userCredentials);
+
+#if defined(ARDUINO_ARCH_ESP32)
+          //Encode with ESP32 built-in library
+          base64 b;
+          String strEncodedCredentials = b.encode(userCredentials);
+          char encodedCredentials[strEncodedCredentials.length() + 1];
+          strEncodedCredentials.toCharArray(encodedCredentials, sizeof(encodedCredentials)); //Convert String to char array
+#else
+          //Encode with nfriendly library
+          int encodedLen = base64_enc_len(strlen(userCredentials));
+          char encodedCredentials[encodedLen];                                         //Create array large enough to house encoded data
+          base64_encode(encodedCredentials, userCredentials, strlen(userCredentials)); //Note: Input array is consumed
+#endif
+
+          snprintf(credentials, sizeof(credentials), "Authorization: Basic %s\r\n", encodedCredentials);
+        }
+        strncat(serverRequest, credentials, SERVER_BUFFER_SIZE);
+        strncat(serverRequest, "\r\n", SERVER_BUFFER_SIZE);
+
+        Serial.print(F("serverRequest size: "));
+        Serial.print(strlen(serverRequest));
+        Serial.print(F(" of "));
+        Serial.print(sizeof(serverRequest));
+        Serial.println(F(" bytes available"));
+
+        Serial.println(F("Sending server request:"));
+        Serial.println(serverRequest);
+        ntripClient.write(serverRequest, strlen(serverRequest));
+
+        //Wait for response
+        unsigned long timeout = millis();
+        while (ntripClient.available() == 0)
+        {
+          if (millis() - timeout > 5000)
+          {
+            Serial.println(F("Caster timed out!"));
+            ntripClient.stop();
+            return;
+          }
+          delay(10);
+        }
+
+        //Check reply
+        bool connectionSuccess = false;
+        char response[512];
+        int responseSpot = 0;
+        while (ntripClient.available())
+        {
+          if (responseSpot == sizeof(response) - 1)
+            break;
+
+          response[responseSpot++] = ntripClient.read();
+          if (strstr(response, "200") > 0) //Look for '200 OK'
+            connectionSuccess = true;
+          if (strstr(response, "401") > 0) //Look for '401 Unauthorized'
+          {
+            Serial.println(F("Hey - your credentials look bad! Check you caster username and password."));
+            connectionSuccess = false;
+          }
+        }
+        response[responseSpot] = '\0';
+
+        Serial.print(F("Caster responded with: "));
+        Serial.println(response);
+
+        if (connectionSuccess == false)
+        {
+          Serial.print(F("Failed to connect to "));
+          Serial.println(casterHost);
+          return;
+        }
+        else
+        {
+          Serial.print(F("Connected to "));
+          Serial.println(casterHost);
+          lastReceivedRTCM_ms = millis(); //Reset timeout
+          ggaTransmitComplete = true;     //Reset to start polling for new GGA data
+        }
+      } //End attempt to connect
+    }   //End connected == false
+
+    if (ntripClient.connected() == true)
+    {
+      uint8_t rtcmData[512 * 4]; //Most incoming data is around 500 bytes but may be larger
+      rtcmCount = 0;
+
+      //Print any available RTCM data
+      while (ntripClient.available())
+      {
+        //Serial.write(ntripClient.read()); //Pipe to serial port is fine but beware, it's a lot of binary data
+        rtcmData[rtcmCount++] = ntripClient.read();
+        if (rtcmCount == sizeof(rtcmData))
+          break;
+      }
+
+      if (rtcmCount > 0)
+      {
+        lastReceivedRTCM_ms = millis();
+
+        //Push RTCM to GNSS module over I2C
+        myGNSS.pushRawData(rtcmData, rtcmCount, false);
+        Serial.print(F("RTCM pushed to ZED: "));
+        Serial.println(rtcmCount);
+      }
+    }
+
+    //Provide the caster with our current position as needed
+    if (ntripClient.connected() == true && transmitLocation == true && (millis() - lastTransmittedGGA_ms) > timeBetweenGGAUpdate_ms && ggaSentenceComplete == true && ggaTransmitComplete == false)
+    {
+      Serial.print(F("Pushing GGA to server: "));
+      Serial.println(ggaSentence);
+
+      lastTransmittedGGA_ms = millis();
+
+      //Push our current GGA sentence to caster
+      ntripClient.print(ggaSentence);
+      ntripClient.print("\r\n");
+
+      ggaTransmitComplete = true;
+
+      //Wait for response
+      unsigned long timeout = millis();
+      while (ntripClient.available() == 0)
+      {
+        if (millis() - timeout > 5000)
+        {
+          Serial.println(F("Caster timed out!"));
+          ntripClient.stop();
+          return;
+        }
+        delay(10);
+      }
+
+      //Check reply
+      bool connectionSuccess = false;
+      char response[512];
+      int responseSpot = 0;
+      while (ntripClient.available())
+      {
+        if (responseSpot == sizeof(response) - 1)
+          break;
+
+        response[responseSpot++] = ntripClient.read();
+        if (strstr(response, "200") > 0) //Look for '200 OK'
+          connectionSuccess = true;
+        if (strstr(response, "401") > 0) //Look for '401 Unauthorized'
+        {
+          Serial.println(F("Hey - your credentials look bad! Check you caster username and password."));
+          connectionSuccess = false;
+        }
+      }
+      response[responseSpot] = '\0';
+
+      Serial.print(F("Caster responded with: "));
+      Serial.println(response);
+    }
+
+    //Close socket if we don't have new data for 10s
+    if (millis() - lastReceivedRTCM_ms > maxTimeBeforeHangup_ms)
+    {
+      Serial.println(F("RTCM timeout. Disconnecting..."));
+      if (ntripClient.connected() == true)
+        ntripClient.stop();
+      return;
+    }
+
+    delay(10);
+  }
+
+  Serial.println(F("User pressed a key"));
+  Serial.println(F("Disconnecting..."));
+  ntripClient.stop();
+}
+
+//This function gets called from the SparkFun u-blox Arduino Library
+//As each NMEA character comes in you can specify what to do with it
+//We will look for and copy the GGA sentence
+void SFE_UBLOX_GNSS::processNMEA(char incoming)
+{
+  //Take the incoming char from the u-blox I2C port and check to see if we should record it or not
+  if (incoming == '$' && ggaTransmitComplete == true)
+  {
+    ggaSentenceStarted = true;
+    ggaSentenceSpot = 0;
+    ggaSentenceEndSpot = sizeof(ggaSentence);
+    ggaSentenceComplete = false;
+  }
+
+  if (ggaSentenceStarted == true)
+  {
+    ggaSentence[ggaSentenceSpot++] = incoming;
+
+    //Make sure we don't go out of bounds
+    if (ggaSentenceSpot == sizeof(ggaSentence))
+    {
+      //Start over
+      ggaSentenceStarted = false;
+    }
+    //Verify this is the GGA setence
+    else if (ggaSentenceSpot == 5 && incoming != 'G')
+    {
+      //Ignore this sentence, start over
+      ggaSentenceStarted = false;
+    }
+    else if (incoming == '*')
+    {
+      //We're near the end. Keep listening for two more bytes to complete the CRC
+      ggaSentenceEndSpot = ggaSentenceSpot + 2;
+    }
+    else if (ggaSentenceSpot == ggaSentenceEndSpot)
+    {
+      ggaSentence[ggaSentenceSpot] = '\0'; //Terminate this string
+      ggaSentenceComplete = true;
+      ggaTransmitComplete = false; //We are ready for transmission
+
+      //Serial.print("GGA Parsed - ");
+      //Serial.println(ggaSentence);
+
+      //Start over
+      ggaSentenceStarted = false;
+    }
+  }
+}

examples/ZED-F9P/Example16_NTRIPClient_WithGGA/secrets.h

@@ -0,0 +1,17 @@
+//Your WiFi credentials
+const char ssid[] = "TRex";
+const char password[] = "parachutes";
+
+//RTK2Go works well and is free
+const char casterHost[] = "rtk2go.com";
+const uint16_t casterPort = 2101;
+const char casterUser[] = "myEmail@test.com"; //User must provide their own email address to use RTK2Go
+const char casterUserPW[] = "";
+const char mountPoint[] = "bldr_SparkFun1"; //The mount point you want to get data from
+
+//Emlid Caster also works well and is free
+//const char casterHost[] = "caster.emlid.com";
+//const uint16_t casterPort = 2101;
+//const char casterUser[] = "u99696"; //User name and pw must be obtained through their web portal
+//const char casterUserPW[] = "466zez";
+//const char mountPoint[] = "MP1979"; //The mount point you want to get data from