GSM GPRS SIM900A module with Stub Antenna and SMA connector

Dear Customer

Please find the code below, also the same code can be used to on/off the pump.


int8_t answer;
int x;

char SMS[200];

void setup(){

 
    Serial.begin(9600);  

    pinMode(8, OUTPUT);
            digitalWrite(8, LOW);
    power_on();
        // turn the LED on (HIGH is the voltage level)
  delay(1000);              // wait for a second


 Serial.println("Network...");
     while( (sendATcommand("AT+CREG?", "+CREG: 0,1", 500) ||
            sendATcommand("AT+CREG?", "+CREG: 0,5", 500)) == 0 );
            
delay(300);
//Signal();
 
    
    Serial.println("Setting SMS mode...");
    sendATcommand("AT+CMGF=1", "OK", 1000);    // sets the SMS mode to text
    delay(300);
     
  sendATcommand("AT+CMGD=1", "OK", 1000);
  Serial.println("SEND SMS... TO READ");
}


void loop(){
   answer = sendATcommand("AT+CMGR=1", "+CMGR:", 2000);    // reads the first SMS
    if (answer == 1)
  {x=0;
        memset(SMS, '\0', 100);
        answer = 0;
        while(Serial.available() == 0);
        // this loop reads the data of the SMS
        do{
            // if there are data in the UART input buffer, reads it and checks for the asnwer
            if(Serial.available() > 0){
           
          
                SMS[x] = Serial.read();
                x++;
                // check if the desired answer (OK) is in the response of the module
             
                
                 if (strstr(SMS, "PUMP ON") != NULL)    
                {
                  digitalWrite(8, HIGH);
                     answer = 1;
                }
                
                  if (strstr(SMS, "PUMP OFF") != NULL)    
                {
                   digitalWrite(8, LOW);
                      answer = 1;
                }
                   if (strstr(SMS, "OK") != NULL)    
                {
                    answer = 1;
                }
                
            }
        }while(answer == 0);    // Waits for the asnwer with time out
        
        
        SMS[x] = '\0';
               Serial.print(SMS);   
          delay(200);
        sendATcommand("AT+CMGD=1", "OK", 1000);   
                 delay(100);
                 sendATcommand("AT+CMGD=1,4", "OK", 1000);
                       delay(200);
                

    }
   
    delay(1000);
 
}

void power_on(){

    uint8_t answer=0;
    
    // checks if the module is started
    answer = sendATcommand("AT", "OK", 2000);
    if (answer == 0)
    {
        
    
        // 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);    
        }
    }
    
}

int8_t sendATcommand(char* ATcommand, char* expected_answer, unsigned int timeout){

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

    memset(response, '\0', 100);    // Initialice 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 there are data in the UART input buffer, reads it and checks for the asnwer
        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_answer) != NULL)    
            {
                answer = 1;
            }
        }
        // Waits for the asnwer with time out
    }while((answer == 0) && ((millis() - previous) < timeout));    

    return answer;
}


void Signal()
{
answer = sendATcommand("AT+CSQ", "+CSQ", 2000);    // reads the first SMS
     
    if (answer == 1)
    {x=0;
        memset(SMS, '\0', 300);
        answer = 0;
        while(Serial.available() == 0);
        // this loop reads the data of the SMS
        do{
            // if there are data in the UART input buffer, reads it and checks for the asnwer
            if(Serial.available() > 0){    
                SMS[x] = Serial.read();
                x++;
       
                if (strstr(SMS, "OK") != NULL)    
                {
                    answer = 1;
                }
            }
        }while(answer == 0);    // Waits for the asnwer with time out
        
        
        SMS[x] = '\0';
         Serial.println(SMS);
         
               delay(100);
    }
    
}

Dear Sir,

HTTPS is not supported by sim900a modems. It supports FTP/HTTP.

Dear Mr.Rahul

You can interface with the laptop using TTL connection.

Rx of the GSM is connected to the TX of the FT232.

Tx of the GSM is connected to Rx of the FT232.

GND is connected to the GND of the FT232 and 12V ,2A supply has to be given additionally.

Please go through the below Image to know how to interface with Ardiuno ,