Electronic Finish Line Judge

This project uses an Arduino Uno and IR sensors to detect who wins a pine wood derby car race.

The schematic and Arduino code can be found below.

/*

 Electrnic line judge

*/

const int statled =  11;      // the number of the LED pin

const int lane1 =  6;

const int lane2 =  7;

const int camera_trigger = 2;

const int lane1sense = 8;

const int lane2sense = 9;

int State = 0; // variable for reading the pushbutton status.

int L1=1, L2=1;      //active low for the beam sensor.

void setup() {

  pinMode(statled, OUTPUT);//running LED

  pinMode(lane1,OUTPUT);//hight is when the light is broken

  pinMode(lane2,OUTPUT);//hight is when the light is broken

  pinMode(camera_trigger, OUTPUT);

  pinMode(lane1sense,INPUT);

  pinMode(lane2sense,INPUT);

  //Ready output

  digitalWrite(lane1,HIGH);//Yellow LED

  digitalWrite(lane2,HIGH);//Blue LED

  delay(250);

  digitalWrite(lane1,LOW);

  digitalWrite(lane2,LOW);

}

void loop(){

  digitalWrite(statled, HIGH);

  L1=digitalRead(lane1sense);

  L2=digitalRead(lane2sense); 

  if((1==L1) or (1==L2)){

    //somebody won the race

      digitalWrite(camera_trigger,HIGH);

      if(1==L1){

        //lane 1 won

        digitalWrite(lane1,HIGH);

      }

      if(1==L2){

        //lane 2 won

        digitalWrite(lane2,HIGH);

      }      

      delay(500);

      digitalWrite(camera_trigger,LOW);

      delay(10000);

      digitalWrite(lane1,LOW);

      digitalWrite(lane2,LOW);

  }

  digitalWrite(statled, LOW);

}