I’m trying to make an Arduino circuit that comes on when you press a momentary button, but then stays on until the Arduino decides it’s time to switch off. Fairly common situation, I’d imagine, but I’ve never done it before.
Is my [attached] schematic workable? Looks sensible to me, but I’ve discovered that that means remarkably little
Basically, I’m imagining that the circuit won’t do anything when power is first applied, as there’s no current through the base/emitter of the TIP102. Press the power button on the right, and the TIP102 will turn on, allowing power through the voltage regulator and therefore powering up the arduino. The first line of code in the arduino will set the ‘power control’ pin high, so it’ll keep the TIP102 powered even after the user has taken the finger off the button.
Then when I want the arduino to power down, all I have to do is set the ‘power control’ pin low.
The two diodes are just acting as an ‘OR’ gate, and to stop current from finding a route straight from the power button to the arduino.
… Or am I making a basic mistake? Thought it was worth asking here before buying the bits.