“M5Stamp PLC Controller with M5StampS3” or just “M5Stack StamPLC” is a programmable logic controller (PLC) based on the StampS3A ESP32-S3 wireless module and offering 8 opto-isolated digital inputs, 4 ...

Sure, it’s probably not the most secure lock on the planet, and the 5V linear regulator is held on to the relay board with hot glue, but this is an exceptionally well-documented project ...