Request regarding interface of SIM900A with Arduino UNO

[kariyappa k]

Dear sir

 

I am trying to interface SIM900A with arduino uno, here is my code. I am not able send the sms when codeis uploaded into arduino board and i am not able to see the reply from sim900 in serial monitor also.please any can help me out.

 

 

Bellow is my code

 

#include<SoftwareSerial.h>
 
SoftwareSerial mySerial(3, 2);     // RX, TX pins
 
int led= 13;
char str;

void setup()
{                
 
  Serial.begin(9600);               
  mySerial.begin(9600);                     // setting the buad rate as 9600
  pinMode(led,OUTPUT);                 // initialize the digital pin as an output.
  Serial.println(“GSM communication initialization”);
  mySerial.println(“AT”);                  // activating the gsm module.
  delay(500);
   mySerial.println(“AT+CMGF=1”);   // setting the gsm module to sms mode.
   delay(500);
   Serial.println(“serial communication begins”);

}

void loop()
{
 
    while(Serial.available() > 0)
    {
        str = mySerial.read();
       Serial.print(str);
    
       if(mySerial.available())
       {
            mySerial.println(“AT+CMGS=”9902062107″”); // mobile number
           delay(500);
           mySerial.println(“hello”); // Message contents
           delay(500);
           mySerial.write(byte(26)); // (signals end of message)
           delay(500);
       }

   }

}

 

[AJISH ALFRED]

Hi Kariyappa,

Check these things;

 

1) The baudrarte should match

2) The voltage levels should match, means the Arduino Uno operates at 5V logic and hence the SIM900A module should be at 5V logic, otherwise use a 5Vto3.3V logic level converter in the serial communication lines.

[kariyappa k]

Hi  Sir

 

I am able to send the sms using SIM900A using my code above mentioned, now i want the sms to be sent to multiple numbers. how can i do that let me give solution as early as possible.

 

Regards

kariyappa K

[arun thapa]

i  am using the same code but i dont know where i have been missed, i am using the same sim900A modem in my project but i am unable to send sms,can u help me sending ur configuration on [email protected],can u suggest how do i know my arduino and gsm have been communicatig.

 

[Anonymous]

looking for a gsm900a to buy in south africa (to interface it with arduino)

urgently contact me on +27 71781 7779

 

[Author]

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