Two control signals one GPIO

[J-M-L]

@ShermanP

Low Low is possible if the battery is not present, or (I think) if a battery protection function has kicked in.

And depending on what the pullup resistors are connected to, High High could occur if there is no, or insufficient, power coming into the charger.

OK if they are possible then as you can't get 4 possibilities with only 1 bit, you either need 2 bits (2 GPIOs) or indeed move to the analog representation