gsm.ino

#include <SoftwareSerial.h>
#include "SIM900.h"

bool gprs_active;
char incoming[255] = "";
bool handling_call;

void setup()
{
  handling_call = false;
  Serial.begin(9600);
  Serial.print("Booting GSM... ");
  if(gsm.begin(1200))
    Serial.println("GSM booted successfully !");
  else
    Serial.println("Failed to boot GSM.");
  gsm.SimpleWriteln("AT+CMEE=2");
  gsm.WhileSimpleRead();
  
  Serial.println("Connecting to the internet...");  
  connectGPRS("wap.iamgprs.ma");
}

void loop()
{
  if(Serial.available())
  {
    char cmd[100] = "";
    byte length = Serial.readBytesUntil('\n', cmd, 99);
    if(length > 0)
    {
      if(strcmp(cmd, "POST") == 0)
      {
        sendPOSTRequest("http://aqueous-plateau-61750.herokuapp.com/gpsdata", "{\"longitude\": 22, \"latitude\": 31}");
        Serial.println("Done !");
      }
      else if(strcmp(cmd, "MSG") == 0)
      {
        Serial.println("Retrieving position...");
        char raw[100] = "", longitude[20] = "", latitude[20] = "", ignore[11];
        retrievePosition(raw, 99);
        Serial.print("Received response : ");
        Serial.println(raw);
        parsePosition(raw, latitude, longitude, ignore, ignore);
        Serial.print("Latitude : ");
        Serial.println(latitude);
        Serial.print("Longitude : ");
        Serial.println(longitude);
        char message[100] = "";
        sprintf(message, "Latitude : %s, longitude = %s\n", latitude, longitude);
        Serial.print("Sending message : ");
        Serial.println(message);
        sendSMS("+212637945221", message);
        Serial.println("Done !");
      }
      else if(strcmp(cmd, "POSITION") == 0)
      {
        Serial.println("Retrieving position...");
        char response[100] = "", json[100] = "";
        char latitude[20] = "", longitude[20] = "", ignore[11] = "";
        retrievePosition(response, 99);
        Serial.print("Response : ");
        Serial.println(response);
        Serial.println("Parsing position...");
        parsePosition(response, latitude, longitude, ignore, ignore);
        Serial.print("Latitude : ");
        Serial.println(latitude);
        Serial.print("Longitude : ");
        Serial.println(longitude);
        sprintf(json, "{\"latitude\": \"%s\", \"longitude\" : \"%s\"}", latitude, longitude);
        Serial.print("JSON : ");
        Serial.println(json);
        Serial.println("Sending coordinates to endpoint..");
        sendPOSTRequest("http://aqueous-plateau-61750.herokuapp.com/gpsdata", json);
        Serial.println("Done !");
      }
      else
      {
        Serial.print("Sending command ");
        Serial.println(cmd);
        gsm.SimpleWriteln(cmd);
        delay(3000);
        gsm.WhileSimpleRead();
      }
    }
  }
  //gsm.WhileSimpleRead();
  if(gsm.read(incoming, 99) > 0)
  {
    Serial.println(incoming);
    //+CLIP: "+212637945221",145,"",,"",0
    if(strstr(incoming, "+CLIP") != NULL)
    {
      char raw[100] = "";
      handling_call = true;
      char phone_number[20] = "";
      sscanf(incoming, "+CLIP: \"%[^\"]\"", phone_number);
      Serial.print("Received a phone call from ");
      Serial.println(phone_number);
      retrievePosition(raw, 99);
      parsePosition(raw,
    }
  }
}

void sendPosition(const char *to, const char *latitude, const char *longitude, int type)
{
  char formatted[100] = "";
  switch(type)
  {
    case EMAIL:
      Serial.println("Email : not implemented yet.");
    break;
    case SMS:
      snprintf(formatted, 99, "Latitude : %s, longitude : %s", latitude, longitude);
      sendSMS(to, formatted);
    break;
    case HTTP:
      snprintf(formatted, 99, "{\"longitude\": \"%s\", \"latitude\": \"%s\"}", longitude, latitude);
      sendPOSTRequest(to, json);
    break;
  }
}

int parsePosition(const char *response, char *latitude, char *longitude, char *date, char *time)
{
  int ignore;
  return sscanf(response, "\n+CIPGSMLOC: %d,%20[^,],%20[^,],%11[^,],%9[^,]", &ignore, longitude, latitude, date, time);
}

void connectGPRS(const char *apn)
{
  gsm.SimpleWriteln("AT+SAPBR=3,1,\"CONTYPE\",\"gprs\"");
  delay(4000);
  gsm.WhileSimpleRead();
  gsm.SimpleWrite("AT+SAPBR=3,1,\"APN\",\"");
  gsm.SimpleWrite(apn);
  gsm.SimpleWriteln("\"");
  delay(4000);
  gsm.WhileSimpleRead();
  gsm.SimpleWriteln("AT+SAPBR=1,1");
  delay(4000);
  gsm.WhileSimpleRead();
  gsm.SimpleWriteln("AT+SAPBR=2,1");
  delay(4000);
  gsm.WhileSimpleRead();
  gprs_active = true;
}

void retrievePosition(char *response, byte length)
{
  if(!gprs_active)
  {
    Serial.println("Unable to retrieve coordinates : not connected to internet.");
    return;
  }
  gsm.WhileSimpleRead();
  gsm.SimpleWriteln("AT+CIPGSMLOC=1,1");
  delay(8000);
  gsm.read(response, length);
}

void sendPOSTRequest(const char *url, const char *data)
{
  if(!gprs_active)
  {
    Serial.println("Unable to send HTTP request : not connected to internet.");
    return;
  }
  
  gsm.SimpleWriteln("AT+HTTPINIT");
  Serial.println("AT+HTTPINIT");
  delay(4000);
  gsm.WhileSimpleRead();
  gsm.WhileSimpleRead();
  gsm.SimpleWriteln("AT+HTTPPARA=\"CID\",1");
  Serial.println("AT+HTTPPARA=\"CID\",1");
  delay(4000);
  gsm.WhileSimpleRead();
  gsm.WhileSimpleRead();
  gsm.SimpleWrite("AT+HTTPPARA=\"URL\",\"");
  Serial.print("AT+HTTPPARA=\"URL\",\"");
  gsm.SimpleWrite(url);
  Serial.print(url);
  gsm.SimpleWriteln("\"");
  Serial.println("\"");
  delay(4000);
  gsm.WhileSimpleRead();
  gsm.WhileSimpleRead();
  
  gsm.SimpleWriteln("AT+HTTPPARA=\"CONTENT\",\"application/json\"");
  Serial.println("AT+HTTPPARA=\"CONTENT\",\"application/json\"");
  delay(4000);
  gsm.WhileSimpleRead();
  gsm.WhileSimpleRead();
  gsm.SimpleWrite("AT+HTTPDATA=");
  Serial.print("AT+HTTPDATA=");
  gsm.SimpleWrite(strlen(data));
  Serial.print(strlen(data));
  gsm.SimpleWriteln(",10000");
  Serial.println(",10000");
  delay(2000);
  gsm.WhileSimpleRead();
  gsm.WhileSimpleRead();
  gsm.SimpleWriteln(data);
  gsm.WhileSimpleRead();
  gsm.WhileSimpleRead();

  delay(4000);
  gsm.SimpleWriteln("AT+HTTPACTION=1");
  Serial.println("AT+HTTPACTION=1");
  //gsm.SimpleWriteln(method);
  delay(4000);
  gsm.WhileSimpleRead();
  gsm.WhileSimpleRead();
  gsm.SimpleWriteln("AT+HTTPREAD");
  Serial.println("AT+HTTPREAD");
  delay(4000);
  gsm.WhileSimpleRead();
  gsm.WhileSimpleRead();
}

void sendSMS(const char *phone_number, const char *message)
{
  char fin[2] = {0x1a, '\0'};
  gsm.SimpleWriteln("AT+CMGF=1");
  delay(2000);
  
  gsm.WhileSimpleRead();
  gsm.SimpleWrite("AT+CMGS=\"");
  gsm.SimpleWrite(phone_number);
  gsm.SimpleWrite("\",");
  gsm.SimpleWriteln(phone_number[0] == '+' ? 145 : 129);
  delay(2000);
  
  gsm.WhileSimpleRead();
  gsm.SimpleWriteln(message);
  delay(2000);
  gsm.WhileSimpleRead();
  gsm.SimpleWrite(fin);
  delay(2000);
  gsm.WhileSimpleRead();
}