Arduino code for posting GPS and sensor reading to Azure:

cloud_poster.ino

#include <b64.h>
#include <ESP8266HTTPClient.h>
#include <ESP8266WiFi.h>
#include <ESP8266WiFiMulti.h>
#include <SoftwareSerial.h>
#include <TinyGPS.h>


static const int RXPin = 12, TXPin = 13; //RX and TX pins for GPS 
TinyGPS gps;
SoftwareSerial ss(RXPin, TXPin); //Emulated using SoftwareSerial Library


char ssid[] = "ssid";            
char pass[] = "password";        
char server[] = "http://yourazurewebsitename.azurewebsites.net"; //Azure function base request URL
char resource[] = "/api/YourTrigger"; //Azure function resource
char code[] = "Azure Function code (part of request url)"; // Azure function code
int status = WL_IDLE_STATUS; 

void setup()
{
  Serial.begin(9600);
  while (!Serial)
    ;
  Serial.print( F("GPSLogger: GPSLogger started\n") );

  ss.begin(9600);
  Serial.print( F("GPSLogger: connecting to SSID ") );
  Serial.println( ssid );     
  Serial.println();   
   WiFi.begin(ssid, pass);
    
    while (WiFi.status() != WL_CONNECTED) {
      //Delay until connected
      delay(500);
      Serial.print(".");
    }
  Serial.print(F("GPSLogger: network module init and connection successful\n"));
   
  IPAddress ip = WiFi.localIP();
  Serial.print(F("GPSLogger: network IP address is "));
  Serial.println(ip);
}

//--------------------------

void loop()
{
  while (ss.available()) {

    char c = ss.read();

    if ( gps.encode(c) )
    {
      
        float flat, flon;

        gps.f_get_position(&flat, &flon);
        Serial.print( F("Location: ") );
        Serial.print( flat == TinyGPS::GPS_INVALID_F_ANGLE ? 0.0 : flat, 6 );
        Serial.print( ',' );
        Serial.print( flon == TinyGPS::GPS_INVALID_F_ANGLE ? 0.0 : flon, 6 );
        Serial.println(); 

        // If connected post readings.

        if ((WiFi.status() == WL_CONNECTED)) { 

  
            int ppmReading = analogRead(A0);
            
            // Build request URL using above details and readings.
            String requestUrl = String(server) + String(resource) + "?code=" + String(code)
                                + "&latitude=" + String(flat, 6) + "&longitude=" + String(flon, 6)
                                + "&ppm=" + String(ppmReading);
            Serial.print("GPSLogger: Posting readings to: ");
            Serial.println(requestUrl);
            
            HTTPClient http;                    
         
            http.begin(requestUrl); //Specify the URL 
            int httpCode = http.GET(); /Make the request
         
            if (httpCode > 0) { //Check for the returning code
         
                String payload = http.getString();
                Serial.print("GPSLogger: status ");
                Serial.println(httpCode);
                Serial.println(payload);
              }
         
            else {
              //Could be good here to possibly hold unposted data to EEPROM.
              Serial.println("Error on HTTP request");
            }
         
            http.end(); 
      } 
        //Delay for two minutes, cleaner to use millis() to prevent blocking.
        delay(120000);
    }
  } 
}