Each page below has code and a picture of the circuit:
Blink: The basic blinky LED. Get your feet wet with a simple sketch.
Photo-Blink: Vary the blink rate with a photoresistor. Learn how to sense the real world.
Photo-Buzzy Blink: Now add a piezo buzzer. Learn how to annoy your flatmates!
LED Fader: Fade an LED in and out. Make a digital circuit pretend to be analog.
LED Fader with Control: Use a potentiometer to adjust the LED's brightness. Take control.
Servo Control: Use the pot to control the position of a servo arm. Learn about libraries.