Open-source boards designed in KiCad by atomicra1n on GitHub, from 3 repositories. A board’s address here is its repository’s there.
atomicra1n/desk-annunciator-panel
A smaller version of alarm panels found in Main Control Rooms of Nuclear Power Plants. Has 12 backlit alarm tiles, a seven segment display (8 digits) and ACK, RESET and TEST buttons.
atomicra1n/stylus-synth
A small synthesizer played with a stylus or a probe (such as a multimeter one). It has 20 copper pads on the PCB acting as a keyboard, a speaker and a headphone jack.
atomicra1n/wifi-geiger-counter
A DIY Geiger counter PCB which can detect ionizing radiation and log readings over Wi-Fi. Built with an ESP32, and a HV multiplier circuit that steps up 3.7V to 400V for the GM tube.