My daughter likes buttons. She's learning letters. I was bored over winter break and had these parts laying around... so I built her a "Button Box" based around an Arduino. Open source, hackable ...

But if you can push your button while your yellow LED is lit, ... Inside the cool laser-cut box is an Arduino Uno and a 9V battery, plus a current-limiting resistor and the all-important buzzer.

The Arduino Uno-compatible board has an MCS-51 (often called 8051 instead) instead of the usual ATmega328P/ATmega168. Specifically, [ElectroBoy] uses the AT89S52 .

To build this project, all you need is three main components: an Arduino Uno, a 16x2 LCD, and a push button. You can connect everything to a breadboard to keep it simple.

And absolutely everything you need comes in the box, including an Uno R3 Arduino board, ... If You're a DIY Tech Lover, This Arduino Kit Subscription Box Is a Must. Brands We Love.