I tried the following program in Arduino to turn off an LED at pin 12. by sending an sms "offa". I used a gprs shield.
I got the following output in serial monitor. and the LED didn't turned OFF.
Can you please say what may be the problem?
code and output are attached
#include <SoftwareSerial.h>
// EN: String buffer for the GPRS shield message
String msg = String("");
// EN: Set to 1 when the next GPRS shield message will contains the SMS message
int SmsContentFlag = 0;
//control pins of relay.
int a=12;
// EN: Code PIN of the SIM card (if applied)
//String SIM_PIN_CODE = String( "XXXX" );
void setup()
{
Serial.begin(19200); // the GPRS baud rate
// Initialize PINs
pinMode( 12, OUTPUT );
digitalWrite( 12, HIGH );
Serial.println( "AT+CMGF=1" );
delay(200);
}
void loop()
{
char SerialInByte;
if(Serial.available())
{
SerialInByte = (unsigned char)Serial.read();
delay(5);
// -------------------------------------------------------------------
// EN: Program also listen to the GPRS shield message.
// -------------------------------------------------------------------
// EN: If the message ends with <CR> then process the message
if( SerialInByte == 13 ){
// EN: Store the char into the message buffer
ProcessGprsMsg();
}
if( SerialInByte == 10 ){
// EN: Skip Line feed
}
else {
// EN: store the current character in the message string buffer
msg += String(SerialInByte);
}
}
}
// EN: Make action based on the content of the SMS.
// Notice than SMS content is the result of the processing of several GPRS shield messages.
void ProcessSms( String sms ){
if( sms.indexOf("offa") >= 0 ){
digitalWrite( a, LOW );
}
}
// EN: Request Text Mode for SMS messaging
void GprsTextModeSMS(){
Serial.println( "AT+CMGF=1" );
}
void GprsReadSmsStore( String SmsStorePos ){
Serial.print( "AT+CMGR=" );
Serial.println( SmsStorePos );
}
// EN: Clear the GPRS shield message buffer
void ClearGprsMsg(){
msg = "";
}
// EN: interpret the GPRS shield message and act appropiately
void ProcessGprsMsg() {
if( msg.indexOf( "Call Ready" ) >= 0 ){
Serial.println( "*** GPRS Shield registered on Mobile Network ***" );
GprsTextModeSMS();
}
// EN: unsolicited message received when getting a SMS message
if( msg.indexOf( "+CMTI" ) >= 0 ){
Serial.println( "*** SMS Received ***" );
// EN: Look for the coma in the full message (+CMTI: "SM",6)
// In the sample, the SMS is stored at position 6
int iPos = msg.indexOf( "," );
String SmsStorePos = msg.substring( iPos+1 );
Serial.print( "SMS stored at " );
Serial.println( SmsStorePos );
// EN: Ask to read the SMS store
GprsReadSmsStore( SmsStorePos );
}
// EN: SMS store readed through UART (result of GprsReadSmsStore request)
if( msg.indexOf( "+CMGR:" ) >= 0 ){
// EN: Next message will contains the BODY of SMS
SmsContentFlag = 1;
// EN: Following lines are essentiel to not clear the flag!
ClearGprsMsg();
return;
}
// EN: +CMGR message just before indicate that the following GRPS Shield message
// (this message) will contains the SMS body
if( SmsContentFlag == 1 ){
Serial.println( "*** SMS MESSAGE CONTENT ***" );
Serial.println( msg );
Serial.println( "*** END OF SMS MESSAGE ***" );
ProcessSms( msg );
}
ClearGprsMsg();
// EN: Always clear the flag
SmsContentFlag = 0;
}
AT+CMGF=1
*** SMS Received ***
SMS stored at 7
AT+CMGR=7