Figure an Arduino most matches the "Other" category. To be specific, it isn't an Arduino brand, it is a DigiSpark, but the trouble isn't with the device itself. The problem is with a buzzer. I got ...

Each buzzer consists of an Arduino Pro Mini 3.3 V, a nRF24L01, and of course a big pushbutton on the top. Each one is powered by a 110 mAh 3.7 V LiPo battery, though ...

The Arduino has something of an ADHD problem, losing interesting and going to sleep in the middle of the tracking process. [Eric’s] workaround uses the RS232 board to periodically reset the ...