Immediately go to sleep if battery is critical

[SZenglein]

Explanation is given in the code.

[laszloh]

You should take a look at System_DeepSleepManager to see what actions are taken before entering the deep sleep.

What I see is, that you do not turn of any peripheral units, so both the AMP and the power system could still be active . I'd at least propose to call the two functions System_PreparePowerDown and Power_PeripheralOff (this one is the more important one) to bring the two GPIO pins to the required level, so the peripherals are unpowered.

[SZenglein]

System_PreparePowerDown is a good pointer.

The thing is, Battery_Init is intentionally placed very early in the setup function, meaning the peripheral power has not yet been turned on. Also Audioplayer has not been initialized, so it should not be exited either.

It has its quirks and order of operations in setup is a difficult topic, but I did design the battery module, the power module and influenced the setup order with all that in mind, and as far as I can see it has not changed.

Essentially, it's treated in the same way as esp_deep_sleep_start in Pn5180 when a false LPCD wakeup ha been detected.

Also, I think you might have missed this because I only wrote it in a private message to @tueddy, but this PR is essentially just reverting this hidden change: 63dc695#diff-f983eb1c0981492d0daafbef571290cd784c5b9cec1526ea3f344f7729e81232L31

I have added a Power_PeripheralOff just because the state of the power pin is kinda undefined at this point and to be sure it is off.

[laszloh]

Yes, I did not knew the history of this change. In the light of it, it looks good.