Building a custom MP3 player for my child, and I am drawing a blank for the power control circuit.
I want a single momentary push button to turn the unit on, and the Arduino will turn it off (not sleep, but full off) after being idle for X seconds. I want power cut to the main power circuit, killing everything for 0 current draw when off. No user input for off at all.
Of course, as cheap and low profile as possible, as I need to shove this in a case.
Thought of a simple dual coil latching relay. May be an option yet. Push button on one coil, Arduino on reset coil. Small cap on the arduino output should give enough to re-set the relay. Kind of big and tall though, and they are $3 and up.
Thought of an SCR connecting the main ground plane to the battery negative wire/terminal, then a darlington transistor controlled by the arduino to short the cathode/anode?
Thought of a solid state relay, where the arduino takes over providing current to the relay once it boots (near instant), switching SOT23 diode keeping power where it needs to be.
Oh, the entire operation takes 130ma max at 6 volts, according to my bench power supply.
Open to thoughts.
