GSM GPRS SIM900A module with Stub Antenna and SMA connector-USB

Dear Sir/Madam,

Kindly click below link for sample sdk code, which will help you in sending and receiving sms using VB.net Windows application.

http://researchdesignlab.com/projects/GSM%20SDK.zip

Dear sir,

Minimum current rating should be 12V 2Amps.

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 Mr.Chiradeep

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

Dear Rahul

Remove the jumper from power key and ground, and connect it to data pin. 

Dear Mr.Rajan

Please click on the below link for the Driver installation,

http://www.ftdichip.com/Drivers/VCP.htm

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

Dear Ramesh,

Please find the code below,

One way to get current time is by sending a message to itself. Below is an example:

AT+CMGF=1 
AT+CSCS="GSM" 
AT+CMGS="0123456789" your phone number
THIS IS TEST test message
...
...
+CMTI: "SM",1 recevied a message at index:1
...
...
AT+CMGR=1
+CMGR: "REC UNREAD","0123456789","","14/11/15,15:03:13+22" got current time
THIS IS TEST

Sync your SIM900 with current time by
AT+CCLK="14/11/15,15:06:45+22"

Note : if you do not want to send an sms and resync the time ,you also use GPRs technique with your own website time or ntp server time