While PIR sensors can be used with Arduino and other microcontroller boards, those best-suited for hobby use are smart enough to perform simple tasks without any programming.

A motion sensor activates the light when it detects something moving within its field of view. Photocells work with a resistor that changes its conductivity based on how many photons are hitting it.

Earlier this year, I decked out my townhouse with a handful of motion sensors. I went with the Aqara P1 ($25, Amazon) sensor because it's affordable, has a battery life that lasts up to five years ...

Aqara’s Thread-based Motion and Light Sensor P2 ($33.99) has been on my smart home wish list since it was announced way back in 2022 — and now, it’s finally here. My home runs on motion ...

This Arduino-based Pomodoro timer project also uses this 25-minute cycle. Once you push the button to start the timer, it will run for 25 minutes, display a count-up timer and a "Study time ...