I have a small project that alerts when a condition is about 3V (high) and off when 1-2V (low). The only thing I'm missing now is some kind of sensor that can give me those conditions. Doesn't really matter what it is just aslong as it's easy to make or buy. Maybe something like a heat, water, motion....
Please feed me some ideas and maybe where I can get the info for it. Thank you.
2 small sheets of aluminium foil as a pressure mat, in series with a button cell when stepped on complete the circuit and provide a button cell voltage to your circuit . Put a resistor to ground on the output of the mat, so its voltage is at zero when not being stepped on, voila