Wake up on power re-applied?

[rickkas7]

I haven't tested this, but I'm pretty sure this should work.

When running, monitor the power good flag so you know when the switch is turned off. Disable the BATFET which disconnects the battery from the Electron, causing the Electron to turn off since there's no mains power.

When you wake up, it's because you have mains power. Run the code to reenable the BATFET, reconnecting the battery.

You should use SYSTEM_MODE(SEMI_AUTOMATIC) so you don't connect to cellular before the battery is connected.

This code shows how to enable and disable the BATFET:

Disabling the Electron red charging LED when not using the LiPo

If you are in a situation where you have a power supply on VIN that can support 1800 mA and do so very quickly, it is possible to use the Electron without the LiPo battery. One use case for this high or low temperature environments, outside of the range of the LiPo. I think I discovered the settings you must make to disable the battery and charging completely. I had missed the watchdog before, and that would cause the charging light to start blinking at odd times, including when sleeping. Then …