Yet another project based on the ESP32, the ESPStop is designed to be a general purpose kill switch for any environment. Requiring only a UDP server to receive the heartbeat messages emitted by the device, nearly any framework can be adapted for use with the ESPStop.
Available on GitHub.
Requiring little more then the safety switch of your choice, an ESP32, and a rechargeable battery, the whole assembly costs only about $20.
Built using the BleepingLibrary, provisioning and configuration of the device is incredibly simple and can be done using just a web browser on either your phone or laptop.