Modified light sensor tutorials for LilyPad Arduino USB. It only differs in that the LilyPad USB has a different (smaller) set of analog pins, so I used a different address, and increased the delay to a half second so it would be easier to read the numbers. Original tutorial is complements of Leah Buechley, found here: http://web.media.mit.edu/~…

light_sensor.ino

/*
 * LilyPad tutorial: sensing (sensors)
 *
 * Reads data from a LilyPad light sensor module
 * and then sends that data to the computer
 * so that you can see the sensor values
 *
 * Original: http://web.media.mit.edu/~leah/LilyPad/08_sensors.html
 */

int ledPin = 13;    // LED is connected to digital pin 13
int sensorPin = 2;  // light sensor is connected to analog pin 2 (A2)
int sensorValue;    // variable to store the value coming from the sensor

void setup()
{  
  pinMode(ledPin, OUTPUT);     // sets the ledPin to be an output
  Serial.begin(9600);          // initialize the serial port
  digitalWrite(ledPin, HIGH);  // turn the LED on
}

void loop() // run over and over again
{  
  sensorValue = analogRead(sensorPin);  // read the value from the sensor
  Serial.println(sensorValue);          // send that value to the computer
  delay(500);                           // delay for 1/2 of a second
}

light_sensor_led.ino

/*
 * LilyPad tutorial: light sensor + LED indicator
 *
 * Reads data from a LilyPad light sensor module and then sends that data to the computer
 * so that you can see the sensor values. It turns the internal LED on when the sensor
 * detects LOW light, and turns the LED off when it detects HIGH light. Like a button!
 *
 * Original: http://web.media.mit.edu/~leah/LilyPad/08_sensors.html
 */

int ledPin = 13;    // LED is connected to digital pin 13
int sensorPin = 2;  // light sensor is connected to analog pin 2 (A2)
int sensorValue;    // variable to store the value coming from the sensor

void setup()
{
  pinMode(ledPin, OUTPUT);     // sets the ledPin to be an output
  Serial.begin(9600);          // initialize the serial port
  digitalWrite(ledPin, HIGH);  // turn the LED on
}

void loop() // run over and over again
{
  sensorValue = analogRead(sensorPin);  // read the value from the sensor
  Serial.println(sensorValue);          // send that value to the computer

  // If the sensor detects a LOW amount of light, turn ON the LED.
  // This makes the light sensor behave sort of like a button.
  if (sensorValue < 100) {
    digitalWrite(ledPin, HIGH);
  }
  // When a moderate amount of light is detected, turn OFF the LED.
  else {
    digitalWrite(ledPin, LOW);
  }

  // delay for 1/100 of a second
  delay(10);
}