LED-GSMShield.txt

#include "SIM900.h"
#include <SoftwareSerial.h>
#include "sms.h"
SMSGSM sms;

int numdata;
boolean started=false;
char smsbuffer[160];
char n[20];
String readString;
char sms_position;
char phone_number[20];
char sms_text[100];
int i;

void setup()
{
    Serial.begin(2400);
    pinMode(13, OUTPUT);
    if (gsm.begin(2400)) 
    {
        Serial.println("\nstatus=READY");
        started=true;
       
    } 
    else 
        Serial.println("\nstatus=IDLE");

    if(started) 
    {
        if (sms.SendSMS("+94771000032", "Arduino SMS"))
        {
          Serial.println("\nSMS sent OK.");
        }
        else
        {
          Serial.println("\nError sending SMS.");
        }      
    }
};

void loop()
{
    if(started) 
    {
        sms_position=sms.IsSMSPresent(SMS_UNREAD);
        if (sms_position) 
        {
            Serial.print("SMS postion:");
            Serial.println(sms_position,DEC);
            sms.GetSMS(sms_position, phone_number, sms_text, 100);
            Serial.println(phone_number);
            Serial.println(sms_text);
            readString += sms_text;
        }      
        readString.trim();
  if (readString.length() >0) {
    if (readString == "on"){
      Serial.println("switching on");
      digitalWrite(13, HIGH);
    }
    if (readString == "off")
    {
      Serial.println("switching off");
      digitalWrite(13, LOW);
    }

    readString="";
  } 
    }  
};