Download the free Arduino IDE to write and upload code.

Runs continuously, carrying out the main logic of your project (e.g., turning an LED on and off). Adventure 3: Interacting with the World

Electronics is about and Outputs . You can expand your Arduino’s capabilities with "Shields" or basic components: You can learn Arduino in 15 minutes.

Runs once at the very start to configure pins (e.g., setting a pin as an OUTPUT ).