In this quick Arduino tutorial I will explain how you can control a relay using the Arduino Board, one 1K and one 10K resistors, 1 BC547 transistor, one 6V or 12V relay, one 1N4007 diode and a 12V fan ...

At points I might do something that might be dangerous because I'm comfortable with some tools or techniques but please always use your common sense and don't try everything you see here.

Boot the Pi and complete the initial setup. 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 ...