Reply by message to sender using Arduino Nano and Sim900 module - arduino

Question

I use arduino Nano and Sim900 module. I want, when a message is received, Arduino to reply back "thanks" to the sender.
My message receive function code is:
void recieveSms(){
Serial.print("\r");
delay(1000);
Serial.print("AT+CMGF=1\r");
delay(1000);
Serial.print("AT+CSCS=\"GSM\"\r");
delay(1000);
Serial.print("AT+CNMI=2,1\r");// set new message remind
delay(1000);
Serial.print("AT+CMGR=2\r"); // read message at position 2
delay(1000);
Serial.print("AT+CMGD=2\r"); // delete SMS at position 2
delay(1000);
}
that works, but how I can retrieve sender number from the message?

Answer 1

Its easy to use the GSM Library that comes with arduino IDE.
The GSM library is included with Arduino IDE 1.0.4 and later.
Using this libarray use remoteNumber()
Here is the example code on the documentation page
#include <GSM.h>
// PIN Number
#define PINNUMBER ""
// initialize the library instance
GSM gsmAccess; // include a 'true' parameter for debug enabled
GSM_SMS sms;
char remoteNumber[20]; // Holds the emitting number
void setup()
{
// initialize serial communications
Serial.begin(9600);
Serial.println("SMS Messages Receiver");
// connection state
boolean notConnected = true;
// Start GSM shield
// If your SIM has PIN, pass it as a parameter of begin() in quotes
while(notConnected)
{
if(gsmAccess.begin(PINNUMBER)==GSM_READY)
notConnected = false;
else
{
Serial.println("Not connected");
delay(1000);
}
}
Serial.println("GSM initialized");
Serial.println("Waiting for messages");
}
void loop()
{
char c;
// If there are any SMSs available()
if (sms.available())
{
Serial.println("Message received from:");
// Get remote number
sms.remoteNumber(remoteNumber, 20);
Serial.println(remoteNumber);
// This is just an example of message disposal
// Messages starting with # should be discarded
if(sms.peek()=='#')
{
Serial.println("Discarded SMS");
sms.flush();
}
// Read message bytes and print them
while(c=sms.read())
Serial.print(c);
Serial.println("\nEND OF MESSAGE");
// delete message from modem memory
sms.flush();
Serial.println("MESSAGE DELETED");
}
delay(1000);
}