The Train of the Future

#include "ATT_IOT_UART.h"      // AllThingsTalk Arduino UART IoT library
#include <SPI.h>               // Required to have support for signed/unsigned long type
#include "keys.h"              // Keep all your personal account information in a seperate file
#include <SoftwareSerial.h>

ATTDevice Device(&Serial1);
char httpServer[] = "api.smartliving.io";          // HTTP API Server host
char mqttServer[] = "broker.smartliving.io";       // MQTT Server Address

// Define PIN numbers for assets
// For digital and analog sensors, we recommend to use the physical pin id as the asset id
// For other sensors (I2C and UART), you can select any unique number as the asset id
#define gpsId 2                // Digital sensor is connected to pin D2 on grove shield

SoftwareSerial SoftSerial(2, 3);
unsigned char buffer[64];                   // Buffer array for data receive over serial port
int count=0;
int time= 30;                               // set time between reading coordinates (in seconds)

// Required for the device
void callback(int pin, String& value);

void setup()
{
  Serial.begin(57600);                                 // Init serial link for debugging
  while(!Serial && millis() < 1000);                   // Make sure you see all output on the monitor. After 1 sec, it will skip this step, so that the board can also work without being connected to a pc
  Serial.println("Starting sketch");
  Serial1.begin(115200);                               // Init serial link for WiFi module
  while(!Serial1);

  while(!Device.StartWifi())
    Serial.println("Retrying...");
  while(!Device.Init(DEVICEID, CLIENTID, CLIENTKEY))   // If we can't succeed to initialize and set the device credentials, there is no point to continue
    Serial.println("Retrying...");
  while(!Device.Connect(httpServer))                   // Connect the device with the AllThingsTalk IOT developer cloud. No point to continue if we can't succeed at this
    Serial.println("Retrying");

  Device.AddAsset(gpsId, "GPS module", "GPS", false, "{\"type\": \"object\",\"properties\": {\"lat\": {\"type\": \"number\", \"unit\": \"°\"},\"lng\": {\"type\": \"number\", \"unit\": \"°\"},\"alt\": {\"type\": \"number\", \"unit\": \"°\"},\"time\": {\"type\": \"integer\", \"unit\": \"epoc time\"}},\"required\": [\"lat\",\"lng\",\"alt\",\"time\" ]}");   // Create the sensor asset for your device

  delay(1000);                                         // Give the WiFi some time to finish everything
  while(!Device.Subscribe(mqttServer, callback))       // Make sure that we can receive message from the AllThingsTalk IOT developer cloud (MQTT). This stops the http connection
    Serial.println("Retrying");

  //pinMode(gpsId, INPUT);                               // Initialize the digital pin as an input.
  SoftSerial.begin(9600);                 // the SoftSerial baud rate
  Serial.println("GPS module is ready for use!");
  delay(2000);
}


float longitude;
float latitude;
float altitude;
float timestamp;
float timestamp1;
float longitude1;
float latitude1;
float distance;
float time_left;
float station = 15.81; 

void loop() 
{
  if(readCoordinates() == true)
  {
     delay(time*1000);
     if(readCoordinates1() == true)SendValue();
  }
  
  Device.Process();
  delay(5000);
}

void SendValue()
{
    float distance = acos(sin(latitude*3.141592654/180)*sin(latitude1*3.141592654/180)+cos(latitude1*3.141592654/180)*cos(latitude*3.141592654/180)*cos(abs(longitude*3.141592654/180-longitude*3.141592654/180)))*6370*1000; 
    float Speed = distance/ time*3600;

    Serial.println(sin(latitude*3.141592654/180)*sin(latitude1*3.141592654/180)+cos(latitude1*3.141592654/180)*cos(latitude*3.141592654/180)*cos(abs((longitude*3.141592654/180)-(longitude1*3.141592654/180))),20);   

    float time_left = station / Speed ; 
    
    Serial.print("sending gps data");
    String data;
    data = "{\"Distance\":" + String(distance, 10)+"km" + ",\"Speed\":" + String(Speed, 3)+"km/h" + ",\"Time left\":" + String(time_left, 3)+"h" + "}";
    Device.Send(data, gpsId);
}

//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////



// Callback function: handles messages that were sent from the iot platform to this device.
void callback(int pin, String& value) 
{ 
    Serial.print("incoming data for: ");         // Display the value that arrived from the AllThingsTalk IOT developer cloud.
    Serial.print(pin);
    Serial.print(", value: ");
    Serial.println(value);
}

bool readCoordinates()
{
  bool foundGPGGA = false;                          // Sensor can return multiple types of data, need to capture lines that start with $GPGGA
    if (SoftSerial.available())                     // If date is coming from software serial port ==> data is coming from SoftSerial shield
    {
        while(SoftSerial.available())               // Reading data into char array
        {
            buffer[count++]=SoftSerial.read();      // Writing data into array
            if(count == 64)break;
        }

        foundGPGGA = count > 60 && ExtractValues();  // If we have less then 60 characters, then we have bogus input, so don't try to parse it or process the values
        clearBufferArray();                          // Call clearBufferArray function to clear the stored data from the array
        count = 0; 
    }
    return foundGPGGA;
}

bool ExtractValues()
{
  unsigned char start = count;
  while(buffer[start] != '$')        // Find the start of the GPS data -> multiple $GPGGA can appear in 1 line, if so, need to take the last one.
  {
    if(start == 0) break;            // It's an unsigned char, so we can't check on <= 0
    start--;
  }
  start++;                           // Remove the '$', don't need to compare with that.
  if(start + 4 < 64 && buffer[start] == 'G' && buffer[start+1] == 'P' && buffer[start+2] == 'G' && buffer[start+3] == 'G' && buffer[start+4] == 'A')      //we found the correct line, so extract the values.
  {
    start+=6;
    timestamp = ExtractValue(start);
    latitude = ConvertDegrees(ExtractValue(start) / 100);
    start = Skip(start);    
    longitude = ConvertDegrees(ExtractValue(start)  / 100);
    start = Skip(start);
    start = Skip(start);
    start = Skip(start);
    start = Skip(start);
    altitude = ExtractValue(start);
    return true;
  }
  else
    return false;
}

float ExtractValue(unsigned char& start)
{
  unsigned char end = start + 1;
  while(end < count && buffer[end] != ',')      // Find the start of the GPS data -> multiple $GPGGA can appear in 1 line, if so, need to take the last one.
    end++;
  buffer[end] = 0;                              // End the string, so we can create a string object from the sub string -> easy to convert to float.
  float result = 0.0;
  if(end != start + 1)                          // If we only found a ',', then there is no value.
    result = String((const char*)(buffer + start)).toFloat();
  start = end + 1;
  return result;
}

//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

bool readCoordinates1()
{
  bool foundGPGGA1 = false;                          // Sensor can return multiple types of data, need to capture lines that start with $GPGGA
    if (SoftSerial.available())                     // If date is coming from software serial port ==> data is coming from SoftSerial shield
    {
        while(SoftSerial.available())               // Reading data into char array
        {
            buffer[count++]=SoftSerial.read();      // Writing data into array
            if(count == 64)break;
        }

        foundGPGGA1 = count > 60 && ExtractValues1();  // If we have less then 60 characters, then we have bogus input, so don't try to parse it or process the values
        clearBufferArray();                          // Call clearBufferArray function to clear the stored data from the array
        count = 0; 
    }
    return foundGPGGA1;
}

bool ExtractValues1()
{
  unsigned char start = count;
  while(buffer[start] != '$')        // Find the start of the GPS data -> multiple $GPGGA can appear in 1 line, if so, need to take the last one.
  {
    if(start == 0) break;            // It's an unsigned char, so we can't check on <= 0
    start--;
  }
  start++;                           // Remove the '$', don't need to compare with that.
  if(start + 4 < 64 && buffer[start] == 'G' && buffer[start+1] == 'P' && buffer[start+2] == 'G' && buffer[start+3] == 'G' && buffer[start+4] == 'A')      //we found the correct line, so extract the values.
  {
    start+=6;
    timestamp1 = ExtractValue(start);
    latitude1 = ConvertDegrees(ExtractValue1(start) / 100);
    start = Skip(start);    
    longitude1 = ConvertDegrees(ExtractValue1(start)  / 100);
    start = Skip(start);
    start = Skip(start);
    start = Skip(start);
    start = Skip(start);
    altitude = ExtractValue1(start);
    return true;
  }
  else
    return false;
}

float ExtractValue1(unsigned char& start)
{
  unsigned char end = start + 1;
  while(end < count && buffer[end] != ',')      // Find the start of the GPS data -> multiple $GPGGA can appear in 1 line, if so, need to take the last one.
    end++;
  buffer[end] = 0;                              // End the string, so we can create a string object from the sub string -> easy to convert to float.
  float result = 0.0;
  if(end != start + 1)                          // If we only found a ',', then there is no value.
    result = String((const char*)(buffer + start)).toFloat();
  start = end + 1;
  return result;
}

//////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
float ConvertDegrees(float input)
{
  float fractional = input - (int)input;
  return (int)input + (fractional / 60.0) * 100.0;
}

unsigned char Skip(unsigned char start)
{
  unsigned char end = start + 1;
  while(end < count && buffer[end] != ',')      // Find the start of the GPS data -> multiple $GPGGA can appear in 1 line, if so, need to take the last one.
    end++;
  return end+1;
}

void clearBufferArray()                         // Function to clear buffer array
{
  for (int i=0; i<count; i++)
  {
    buffer[i] = NULL;                           // Clear all index of array with command NULL
  }
}