volatile int NbTopsFan; //measuring the rising edges of the signal
  int Calc;                               
  int hallsensor = 2;    //The pin location of the sensor
  int total = 0;
  int temp=0;
  int counter =0;
  int hitung = 0;
  char buffer_kirim[100];
  char url[]="www.cobaserver.hosting.com";


int8_t answer, respond;
byte gsmDriverPin[3] = {
  3,4,5};

void rpm ()     //This is the function that the interupt calls 
{ 
  NbTopsFan++;  //This function measures the rising and falling edge of the hall effect sensors signal
} 

void setup()
{
    for(int i = 0 ; i < 3; i++){
      pinMode(gsmDriverPin[i],OUTPUT);
    }
    //Output GSM Timing 
    digitalWrite(5,HIGH);
    delay(1500);
    digitalWrite(5,LOW); 
    delay(2000);
    pinMode(hallsensor, INPUT);
    Serial.begin(9600); //set the baud rate
    delay(5000);
    attachInterrupt(0, rpm, RISING);
    delay(5000);

    Serial.println("Starting...");
    power_on();
    delay(3000);
    sendATcommand("AT+CPIN=****", "OK", 2000);
    delay(3000);
    
    /*Konfigurasi APN*/
    while (sendATcommand2("AT+CREG?", "+CREG: 0,1", "+CREG: 0,5", 2000) == 0);
    sendATcommand("AT+SAPBR=3,1,\"Contype\",\"GPRS\"", "OK", 2000);
    sendATcommand("AT+SAPBR=3,1,\"APN\",\"indosatgprs\"", "OK", 2000);
    sendATcommand("AT+SAPBR=3,1,\"USER\",\"\"", "OK", 2000);
    sendATcommand("AT+SAPBR=3,1,\"PWD\",\"\"", "OK", 2000);
      
    if ((sendATcommand("AT+SAPBR=1,1", "OK", 10000)) == 0)
    Serial.println ("Waiting...");
}

void loop()
{
  /*Fungsi mengambil data dari sensor flowemeter*/
  NbTopsFan = 0;   //Set NbTops to 0 ready for calculations
  sei();      //Enables interrupts
  delay (1000);   //Wait 1 second
  cli();      //Disable interrupts
  Calc = (NbTopsFan / 7.5); //(Pulse frequency x 60) / 7.5Q, = flow rate in L/hour 

    Serial.print("Counter : ");
    Serial.println(counter);
    Serial.print(Calc);
    Serial.println(" L/min");

    if(Calc == 0 && total!=0 && counter==4)
    {
       HTTP(total); //kirim data melalui HTTP POST
       total=0; //ubah data total menjadi 0
    }
    else
    {
      temp=Calc;
      total=total+temp;
      
    }
    counter++;
      if(counter==5)
      {
        Serial.print("Total : ");
        Serial.println(total);
        Serial.println("");
        counter=0;
      }    
  
}

/*Fungsi Kirim data via HTTP*/
void HTTP(int data)
{
  Serial.println("AT+HTTPINIT");
  delay(5000);
  Serial.println("AT+HTTPPARA=\"CID\",1");
  delay(5000);
  
  sprintf(buffer_kirim,"AT+HTTPPARA=\"URL\",\"http://%s/insert_data.php?lat=70.0000&lon=140.00000&data_air=%d\" ",url,data);
  Serial.println(buffer_kirim);
  delay(5000);
  Serial.println("AT+HTTPACTION=0");
  delay(5000);
  Serial.println("AT+HTTPREAD=0");
}

/*Fungsi Inisialisasi Hardware*/
uint8_t power_on(){

    uint8_t answer=0;

    // checks if the module is started
    answer = sendATcommand("AT", "OK", 2000);
    if (answer == 0)
    {
        // power on pulse
        digitalWrite(4,HIGH); //Disable GPS
        delay(2000);
        digitalWrite(3,LOW); //Enable GSM

        // waits for an answer from the module
        while(answer == 0){  
            // Send AT every two seconds and wait for the answer   
            answer = sendATcommand("AT", "OK", 2000);    
        }
    }
    return answer;
}

/*Fungsi sendATcommand untuk memudahkan komunikasi dengan output 1 jawaban*/
int8_t sendATcommand(char* ATcommand, char* expected_answer1, unsigned int timeout){

    uint8_t x=0,  answer=0;
    char response[100];
    unsigned long previous;

    memset(response, '\0', 100);    // Initialize the string

    delay(100);

    while( Serial.available() > 0) Serial.read();    // Clean the input buffer

    Serial.println(ATcommand);    // Send the AT command 


        x = 0;
    previous = millis();

    // this loop waits for the answer
    do{
        if(Serial.available() != 0){    
            response[x] = Serial.read();
            x++;
            // check if the desired answer is in the response of the module
            if (strstr(response, expected_answer1) != NULL)    
            {
                answer = 1;
            }
        }
        // Waits for the asnwer with time out
    }
    while((answer == 0) && ((millis() - previous) < timeout));    

    return answer;
}

/*Fungsi sendATcommand untuk memudahkan komunikasi dengan output 2 jawaban*/
int8_t sendATcommand2(char* ATcommand, char* expected_answer1, 
char* expected_answer2, unsigned int timeout){

    uint8_t x=0,  answer=0;
    char response[100];
    unsigned long previous;

    memset(response, '\0', 100);    // Initialize the string

    delay(100);

    while( Serial.available() > 0) Serial.read();    // Clean the input buffer

    Serial.println(ATcommand);    // Send the AT command 


        x = 0;
    previous = millis();

    // this loop waits for the answer
    do{        
        if(Serial.available() != 0){    
            response[x] = Serial.read();
            x++;
            // check if the desired answer 1 is in the response of the module
            if (strstr(response, expected_answer1) != NULL)    
            {
                answer = 1;
            }
            // check if the desired answer 2 is in the response of the module
            if (strstr(response, expected_answer2) != NULL)    
            {
                answer = 2;
            }
        }
        // Waits for the asnwer with time out
    }while((answer == 0) && ((millis() - previous) < timeout));    

    return answer;
}