The sensor shown here is essentially two plates mounted side-by-side, attached to an Arduino Nano using the Capacitor library which uses just two pins, one digital and one analog.

After some searching, I ended up using a microcontroller and a piece of code borrowed from the web that I tweaked and adapted. The microcontroller-based concept was chosen because I wanted to scale ...

Use Arduino to handle sensor input and relay control. Pi runs a Python Flask server with a simple UI to toggle GPIO pins via serial commands sent to the Arduino. Use cron jobs on Linux to schedule ...