I know that the Raspberry Pi 3G/4G & LTE Base HAT “can be powered from an external 5V source by exposed power pins, directly from Raspberry Pi 5V GPIO headers, via micro USB, or optional JST connector on the bottom of the board”. And I also remember that “the power of the whole board electronics can be disabled for low-power consumption use cases”.
What I don’t know is if I can I power both the 3G/4G & LTE Base HAT and the Raspberry Pi via the external 5V source by exposed power pins or optional JST connector on the bottom of the board. May I?
In that case, would I be able to disabled the power of the whole board electronics for low-power consumption use cases, keeping the Raspberry Pi powered on?
Don’t know if this may sound absurd, but in my use case I would not be able to hook up a USB cable to the microUSB connector on the Raspberry, so two alternative option would be to power on the Raspberry Pi and the HAT either via the HAT or the GPIO.
In the end, is there any kind of protection on the exposed power pins or the optional JST connector? That is, polarity, over-voltage, etcetera.