Your first sketches: blink, read sensors, drive actuators, talk over Serial.
Make the on-board LED blink — the 'Hello World' of every microcontroller.
Light up a control panel that reacts when you press a launch button.
Measure body heat with a TMP36 and light up 1, 2 or 3 LEDs.
Mix red, green and blue light with three light sensors.
Wave your hand over a sensor to play musical notes through a buzzer.