Impulse relay turns on with an electrical impulse at the control input and turns off again with another impulse.

This is an ingenious design idea for learning how simple metal detectors/locators work. That’s really all there’s to it. Oh, that’s enough theory talk for now! Let’s get on with testing the $5 Chinese ...

I couldn’t find a module capable to be directly plugged onto the GPIO pins of the raspberry. In addition to the slacky connection with the wires, I didn’t like the simple modules for some more ...