#include <SoftwareSerial.h>
#include <LiquidCrystal.h> 

// Replace xxxxxxxxxx with your cell phone number where you want text messages arrive.

String msg = String("");
// EN: Set to 1 when the next GPRS shield message will contains the SMS message
LiquidCrystal lcd(2, 3, 10, 11, 12, 13);    // Pinout, RS=2, E=3, DB4=10, DB5=11, DB6=12, DB7=13.
int numRows = 2;                            // Number of rows of the LCD.  
int numCols = 16;                           // Number of Columns of the LCD.
int SmsContentFlag = 0;

//control pins of relay.
int relay_a=4;
int relay_b=5;
int relay_c=6;
int relay_d=7;

int val = 0;     //variable to store the value read from button
 
void setup()
{
  Serial.begin(9600);
  lcd.begin(numRows, numCols);
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print("*    Arduino   *");
  lcd.setCursor(0,1);
  lcd.print("*   Professor  *"); 
  delay(2000);
  
 Serial.begin(19200);                 // the GPRS baud rate

 
 // Encender el Modulo GPRS:
  
 pinMode(9, OUTPUT);  // Pin 9  "PowerKey" of SIM900 shield.
 digitalWrite(9,LOW);
 delay(1000);
 digitalWrite(9,HIGH);
 delay(2000);
 digitalWrite(9,LOW);
 delay(2000); 
 
  lcd.begin(numRows, numCols);
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print("*    SIM900    *");
  lcd.setCursor(0,1);
  lcd.print("*  Module - ON *"); 
 //************************
 
  // Initialize  PINs
  
  pinMode( 4, OUTPUT ); 
  pinMode( 5, OUTPUT ); 
  pinMode( 6, OUTPUT ); 
  pinMode( 7, OUTPUT ); 
  
  digitalWrite( 4, LOW ); 
  digitalWrite( 5, LOW ); 
  digitalWrite( 6, LOW );
  digitalWrite( 7, LOW );
  
 Serial.println( "AT+CMGF=1" ); // SMS Text mode active
 delay(200);
 Serial.println( "AT+CMGD=1,4" ); // Delete all SMS message in the SIM900 memory.
 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("Ona") >= 0 ){
    digitalWrite( relay_a, HIGH );

    lcd.clear();
    lcd.setCursor(0,0);
    lcd.print("*   Relay #1   *");
    lcd.setCursor(0,1);
    lcd.print("*  Activated!  *"); 
  
    Serial.println( "AT+CMGD=1,4" ); // Delete all SMS message in the SIM900 memory.
    delay(200);
    
    Serial.print("AT+CMGF=1\r");    // SMS Text mode active
    delay(500);
    Serial.println("AT+CMGS=\"xxxxxxxxxx\"");          // send the SMS the number
    delay(500);
    Serial.println("Relay #1 = ON");     // the SMS body
    delay(500);
    Serial.println((char)26);             // end of message command 1A (hex) 
    delay(500);
    Serial.println();
    //***********************************************************************************
  }
   if( sms.indexOf("Onb") >= 0 ){
    digitalWrite(  relay_b, HIGH );

    lcd.clear();
    lcd.setCursor(0,0);
    lcd.print("*   Relay #2   *");
    lcd.setCursor(0,1);
    lcd.print("*  Activated!   *");     
    
    Serial.println( "AT+CMGD=1,4" ); // Delete all SMS message in the SIM900 memory.
    delay(200);

    Serial.print("AT+CMGF=1\r");    // SMS Text mode active
    delay(500);
    Serial.println("AT+CMGS=\"xxxxxxxxxx\"");          // send the SMS the number
    delay(500);
    Serial.println("Relay #2 = ON");     // the SMS body
    delay(500);
    Serial.println((char)26);             // end of message command 1A (hex) 
    delay(500);
    Serial.println();
    //***********************************************************************************
  }
   if( sms.indexOf("Onc") >= 0 ){
    digitalWrite(  relay_c, HIGH );
        
    lcd.clear();
    lcd.setCursor(0,0);
    lcd.print("*   Relay #3   *");
    lcd.setCursor(0,1);
    lcd.print("*  Activated!  *"); 
    
    Serial.println( "AT+CMGD=1,4" ); // Delete all SMS message in the SIM900 memory.
    delay(200);

    Serial.print("AT+CMGF=1\r");    // SMS Text mode active
    delay(500);
    Serial.println("AT+CMGS=\"xxxxxxxxxx\"");          // send the SMS the number
    delay(500);
    Serial.println("Relay #3 = ON");     // the SMS body
    delay(500);
    Serial.println((char)26);             // end of message command 1A (hex) 
    delay(500);
    Serial.println();
    //************************************************************************************
  }

   if( sms.indexOf("Ond") >= 0 ){
    digitalWrite(  relay_d, HIGH );
        
    lcd.clear();
    lcd.setCursor(0,0);
    lcd.print("*   Relay #4   *");
    lcd.setCursor(0,1);
    lcd.print("*  Activated!  *"); 
    
    Serial.println( "AT+CMGD=1,4" ); // Delete all SMS message in the SIM900 memory.
    delay(200);

    Serial.print("AT+CMGF=1\r");    // SMS Text mode active
    delay(500);
    Serial.println("AT+CMGS=\"xxxxxxxxxx\"");          // send the SMS the number
    delay(500);
    Serial.println("Relay #4 = ON");     // the SMS body
    delay(500);
    Serial.println((char)26);             // end of message command 1A (hex) 
    delay(500);
    Serial.println();
    //************************************************************************************
  }
  
  if( sms.indexOf("Allon") >= 0 ){  // ENCIENDE TODOS LOS LEDS
    digitalWrite( relay_a, HIGH );
    digitalWrite(  relay_b, HIGH );
    digitalWrite(  relay_c, HIGH );
    digitalWrite(  relay_d, HIGH );   

    lcd.clear();
    lcd.setCursor(0,0);
    lcd.print("*  All Relays   *");
    lcd.setCursor(0,1);
    lcd.print("*  Activated    *");     
    
    
    Serial.println( "AT+CMGD=1,4" ); // Delete all SMS message in the SIM900 memory.
    delay(200);

    Serial.print("AT+CMGF=1\r");    // SMS Text mode active
    delay(500);
    Serial.println("AT+CMGS=\"xxxxxxxxxx\"");          // send the SMS the number
    delay(500);
    Serial.println("All relays = ON");     // the SMS body
    delay(500);
    Serial.println((char)26);             // end of message command 1A (hex) 
    delay(500);
    Serial.println();
    //*************************************************************************************
  }
  
  if( sms.indexOf("Offa") >= 0 ){
    digitalWrite(  relay_a, LOW );
    
    lcd.clear();
    lcd.setCursor(0,0);
    lcd.print("*   Relay #1   *");
    lcd.setCursor(0,1);
    lcd.print("*   Desable!   *");     
    
    Serial.println( "AT+CMGD=1,4" ); // Delete all SMS message in the SIM900 memory.
    delay(200);

    Serial.print("AT+CMGF=1\r");    // SMS Text mode active
    delay(500);
    Serial.println("AT+CMGS=\"xxxxxxxxxx\"");          // send the SMS the number
    delay(500);
    Serial.println("Relay #1 = OFF");     // the SMS body
    delay(500);
    Serial.println((char)26);             // end of message command 1A (hex) 
    delay(500);
    Serial.println();
    //*************************************************************************************
  }
  if( sms.indexOf("Offb") >= 0 ){
    digitalWrite(  relay_b, LOW );
    
    lcd.clear();
    lcd.setCursor(0,0);
    lcd.print("*   Relay #2   *");
    lcd.setCursor(0,1);
    lcd.print("*   Desable!   *"); 
    
    Serial.println( "AT+CMGD=1,4" ); // Delete all SMS message in the SIM900 memory.
    delay(200);

    Serial.print("AT+CMGF=1\r");    // SMS Text mode active
    delay(500);
    Serial.println("AT+CMGS=\"xxxxxxxxxx\"");          // send the SMS the number
    delay(500);
    Serial.println("Relay #2 = OFF");     // the SMS body
    delay(500);
    Serial.println((char)26);             // end of message command 1A (hex) 
    delay(500);
    Serial.println();
    //*************************************************************************************
  }
  if( sms.indexOf("Offc") >= 0 ){
    digitalWrite(  relay_c, LOW );
    
    lcd.clear();
    lcd.setCursor(0,0);
    lcd.print("*   Relay #3   *");
    lcd.setCursor(0,1);
    lcd.print("*   Desable!   *"); 
    
    Serial.println( "AT+CMGD=1,4" ); // Delete all SMS message in the SIM900 memory.
    delay(200);

    Serial.print("AT+CMGF=1\r");    // SMS Text mode active
    delay(500);
    Serial.println("AT+CMGS=\"xxxxxxxxxx\"");          // send the SMS the number
    delay(500);
    Serial.println("Relay #3 = OFF");     // the SMS body
    delay(500);
    Serial.println((char)26);             // end of message command 1A (hex) 
    delay(500);
    Serial.println();
    //*************************************************************************************
  }
  
    if( sms.indexOf("Offd") >= 0 ){
    digitalWrite(  relay_d, LOW );
    
    lcd.clear();
    lcd.setCursor(0,0);
    lcd.print("*   Relay #4   *");
    lcd.setCursor(0,1);
    lcd.print("*   Desable!   *"); 
    
    Serial.println( "AT+CMGD=1,4" ); // Delete all SMS message in the SIM900 memory.
    delay(200);

    Serial.print("AT+CMGF=1\r");    // SMS Text mode active
    delay(500);
    Serial.println("AT+CMGS=\"xxxxxxxxxx\"");          // send the SMS the number
    delay(500);
    Serial.println("Relay #4 = OFF");     // the SMS body
    delay(500);
    Serial.println((char)26);             // end of message command 1A (hex) 
    delay(500);
    Serial.println();
    //*************************************************************************************
  }

  if( sms.indexOf("Alloff") >= 0 ){ // APAGAR TODOS LOS LEDS
    digitalWrite(  relay_a, LOW );
    digitalWrite(  relay_b, LOW );
    digitalWrite(  relay_c, LOW );    
    digitalWrite(  relay_d, LOW ); 
    
    lcd.clear();
    lcd.setCursor(0,0);
    lcd.print("*  All relays  *");
    lcd.setCursor(0,1);
    lcd.print("*   Desable!   *");     
    
    Serial.println( "AT+CMGD=1,4" ); // Delete all SMS message in the SIM900 memory.
    delay(200);

    Serial.print("AT+CMGF=1\r");    // SMS Text mode active
    delay(500);
    Serial.println("AT+CMGS=\"xxxxxxxxxx\"");          // send the SMS the number
    delay(500);
    Serial.println("All relays = OFF");     // the SMS body
    delay(500);
    Serial.println((char)26);             // end of message command 1A (hex) 
    delay(500);
    Serial.println();
    //**************************************************************************************
  }


}
// 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; 
}