Check out the new project site for Light Attack (IR Paintball) http://www.project.lightattack.com.au

Sunday, March 21, 2010

Arduino code for 38KHz IR signal (LazerTag)

Below will produce the "fire" 38Khz modulated IR signal for interacting with LazerTag guns.  It was written for the Arduino but easily run on a AVR 328/168 straight away.
//PINS
int trigger = 2;  //digital pin 2 but also known as interrupt 0
int IR_RECV = 0;  //Pin to receive TTL received IR pulses on
int IRLED = 7;    //Drives the sending IR LED
int magazine = 0;  //reads if magazine inserted - active low - held high by 26k ohm resistor
int rumble_motor = 0;

int carrier1 = 0;
int carrier2 = 0;


unsigned long time_delay_usec_elapsed =0;
unsigned long time_delay_usec_start = 0;
int temp_flash = 1;  

boolean shot_firing = false;    //used as a bool for telling whether we are currently in the process of firing a shot or not


void setup()
{
  pinMode(13, OUTPUT);
  pinMode(2, INPUT);
  pinMode(IR_RECV, INPUT);
  pinMode(IRLED, OUTPUT);
  pinMode(rumble_motor, OUTPUT);
  pinMode(carrier1, OUTPUT);
  pinMode(carrier2, OUTPUT);
  
  //set up interrupts
//  attachInterrupt(0, fire_shot, FALLING);    //attaches the fire_shot() function to the interrupt 0 which is on pin 2 
//  attachInterrupt(1, receive_shot, FALLING);  //detects signal from photo diodes on PIN 3

  //initialise pins
  digitalWrite(IRLED, LOW);
  digitalWrite(13, HIGH);
  digitalWrite(rumble_motor, 0);

//Setup 38Khz carrier wave
  pinMode(3, INPUT);  //Don't need it
  pinMode(11, OUTPUT);
//Normal mode
  TCCR2A = 0x00;
  bitWrite(TCCR2A, COM2A0, 1);
  bitWrite(TCCR2A, COM2B1, 1);
  bitWrite(TCCR2A, WGM21, 1);
  bitWrite(TCCR2A, WGM20, 1);

  TCCR2B = 0x00;
  bitWrite(TCCR2B, WGM22, 1);
  bitWrite(TCCR2B, CS20, 1);  

  OCR2A = 209;
  OCR2B = 128;  //Doesn't matter

  

 
 


// analogWrite(rumble_motor, 128); 
 
}

void loop()
{

 pinMode(11, INPUT);
 digitalWrite(11, HIGH);
 
 if(digitalRead(2) == LOW) //trigger pulled
 {
 
      //NEW APPROACH - turn off interrupts and send FIRING signals direct
      
      noInterrupts();
 
 
      //on 3ms
      pinMode(11, OUTPUT);
   
      bitWrite(TCCR2B, CS20, 1);
      delayMicroseconds(3000);

      //off 6ms
      pinMode(11, INPUT);
      digitalWrite(11, HIGH);
      delayMicroseconds(6000);

      //on 3ms
      pinMode(11, OUTPUT);
      delayMicroseconds(3000);
//1 
      //off 2ms
      pinMode(11, INPUT);      
      digitalWrite(11, HIGH);
      delayMicroseconds(2000);
            
      //on 1ms
      pinMode(11, OUTPUT);
      delayMicroseconds(1000);
//2      
      //off 2ms
      pinMode(11, INPUT);      
      digitalWrite(11, HIGH);
      delayMicroseconds(2000);
            
      //on 1ms
      pinMode(11, OUTPUT);
      delayMicroseconds(1000);

//3      
      //off 2ms
      pinMode(11, INPUT);      
      digitalWrite(11, HIGH);
      delayMicroseconds(2000);
            
      //on 1ms
      pinMode(11, OUTPUT);
      delayMicroseconds(1000);
//4      
      //off 2ms
      pinMode(11, INPUT);      
      digitalWrite(11, HIGH);
      delayMicroseconds(2000);
            
      //on 1ms
      pinMode(11, OUTPUT);
      delayMicroseconds(1000);
//5      
      //off 2ms
      pinMode(11, INPUT);      
      digitalWrite(11, HIGH);
      delayMicroseconds(2000);
            
      //on 1ms
      pinMode(11, OUTPUT);
      delayMicroseconds(1000);
//6      
      //off 2ms
      pinMode(11, INPUT);      
      digitalWrite(11, HIGH);
      delayMicroseconds(2000);
            
      //on 1ms
      pinMode(11, OUTPUT);
      delayMicroseconds(1000);
//7      
      //off 2ms
      pinMode(11, INPUT);      
      digitalWrite(11, HIGH);
      delayMicroseconds(2000);
            
      //on 1ms
      pinMode(11, OUTPUT);
      delayMicroseconds(1000);

      
      pinMode(11, INPUT);
      digitalWrite(11, HIGH);
        
      interrupts();
      delay(500);
    
      
 }
 

    
 





}

2 comments:

Matt Williamson said...

Thanks for this bit of code. I'm using it to have robots track each other.

Dingo_aus said...

You're welcome