I’ve got a little project for a custom egg timer that lights up some LEDs and makes beeps in order to tell us when to put the toast on and take the eggs out for optimal egg + toast timing.
I’m using an ItsyBitsy M0 Express, and it’s a completely stateless program. On power-on or reset, it starts the timing sequence, runs through the process and then just ends. I’ve got a button hooked up to RST on the ItsyBitsy to reset it as required.
I’m using a Trinket LiPoly backpack to attach a battery, and I want the battery life to be a long as possible between recharges. When the program exits, I’m left with an LED on the backpack still lit, and a flashing light on the ItsyBitsy. Is there something I can do to drop the power usage any further (without unplugging anything) than just exiting the program?
I’ve read How to Conserve Battery Life with IoT Projects - Tutorial Australia, but it doesn’t give any details of how to enter what it calls “Stop Mode”. Is exiting the program doing that? Is there something else I need to do in my CircuitPython code other than just exit?