This guide will show two ways to build a hand washing timer. Bored of singing "Happy Birthday"? This countdown timer will help you scrub your hands with soap for a full 20 seconds with confidence, as outlined by the US Centers For Disease Control and Prevention handwashing guidelines.

Plus, there's no need to touch the timer, in order keep it clean.

Two different version of the project here -- one in MakeCode for Circuit Playground Express, the other in CircuitPython for the CLUE. Use a loud sound, such as a clap or snap to activate the CPX timer, or a wave of a hand to start the CLUE.

This is a great beginner project to show how to make a real product with a few 'blocks' of code!


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This guide was first published on Apr 01, 2020. It was last updated on Feb 21, 2024.

This page (Overview) was last updated on Mar 24, 2020.

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