Laser diode are available in various sizes and can be interfaced with Arduino Uno using photoresistors, photodiodes, sensors & detectors.

The idea is to combine the capacities of an Arduino Micro with those of a NodeMCU 8266 for building a programmable button box. Here is what we take from the two worlds: A simple web interface let the ...

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, and made by hand.