I have an M5core that will occasionally shut off when if the battery is still at 3.9V. I'm trying to figure out if it's a software issue or a hardware issue. Once the device is shut off, the power button will not revive the device. The only way to revive the device is to either plug in USB or disconnect / reconnect the battery.
What's weird is the shutdown seems to happen randomly and MIGHT be tied to my code (i.e. one version of my code seems to exhibit this behavior while others don't)... and also the amount of time the device can function before shutdown seems to be non-deterministic (at least I can't find a pattern right now).
What could I be doing in the software that can cause the core to randomly turn itself off to the point that the power button isn't even responsive?