[General] Problem in interfacing SIM900 with Arduino UNO

[Vijayprakash]

Hello Every one,

Am try to send and Receive SMS from SIM900 with the help of Arduino UNO, I have write a program for that but SIM 900 performing all the function like receiving Message , Calling to Someone, Receving call but not sending SMS

My program as follows:

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#include <SoftwareSerial.h>
SoftwareSerial mySerial(7, 8);
char incoming_char=0; 
void setup()
{
  Serial.begin(9600);
  mySerial.begin(2400);
  delay(20000);  // give time to log on to network. 
  mySerial.println("ATV1");
  delay(100);
  mySerial.println("ATE0");
  delay(100);
  mySerial.println("AT+CMGF=1");
  delay(100);
  mySerial.println("AT+CMGD=1");
  delay(1000);
  mySerial.println("AT+CNMI=2,2,0,0,0\r");
  delay(100);
  mySerial.println("AT+CMGR=1"); 
  delay(200);
 
}
 
 
void sendSMS()
{
  
 mySerial.println("AT+CMGS="+917045610408" ");   // recipient's mobile number, in international               format
  delay(100);
  mySerial.println("Hello");        // message to send
  delay(100);
  mySerial.println((char)26);                       // End AT command with a ^Z, ASCII code 26
  delay(100); 
  Serial.println("msg sent");
  mySerial.println();
  delay(5000);                                     // give module time to send SMS
 
}
 void callSomeone()
{
  mySerial.println("ATD + +917045610408;"); // dial US (212) 8675309
  delay(100);
  mySerial.println();
  Serial.println("GSM Test1");
  delay(30000);            // wait for 30 seconds...
  mySerial.println("ATH");   // hang up
  Serial.println("GSM Test2");
}
 
void loop()
{
 
  if(mySerial.available() >0)
  {
    incoming_char=mySerial.read(); //Get the character from the cellular serial port.
  Serial.print(incoming_char); //Print the incoming character to the terminal.
    if(incoming_char=='a')
    {
 
      Serial.println("Coin Acceptor OFF");
      callSomeone();
      delay(100);
       sendSMS();
       delay(100);
    }
  }
 
}

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Please help me out

Thanks

 

[FenTrac]

You might want to look at this previous thread.

https://www.edaboard.com/threads/219547/