led.c

//TOUCH SENSING BETA - LED TURNS ON WHEN LIGHT IS PRESENT
//BY: RICARDO DE LEMOS 1/17/2007
int led1 = 13;
int cath = 2; // negative
int ando = 3;  // positive

void setup()
{
  pinMode(led1, OUTPUT);
  pinMode(cath, OUTPUT);
  pinMode(ando, OUTPUT);
  Serial.begin(9600);
}

void loop()
{
  //REVERSE BIAS
  digitalWrite(cath, HIGH);
  digitalWrite(ando, LOW);
  //CHARGE LED
  delay(6);
  //READ LED CAP
  pinMode(ando, INPUT);
  delay(6);
  //WRITE TO LED
  if (digitalRead(ando) == LOW)
  {
    digitalWrite(led1,HIGH);
    Serial.print("ON");
  }
  else
  {
    digitalWrite(led1,LOW);
    Serial.print("OFF");
  }
  //RESET
  pinMode(ando, OUTPUT);
}