[SOLVED] CubeCell AB01: how to detach ADC from Vext

[superslot]

Hi,

I need to use the onboard ADC to read an external voltage while I’m having Vext=ON all the time (I’m powering up the external sensor)

AFAIK from the documentation when Vext is ON (GPIO06) the ADC will always read the battery level.

How can I modify the board and make the ADC completely “independent”??

looking to a previous answer it seems to me that if I remove BR1 then the ADC pin on the AB01 is completely free and will always measure whatever voltage I place on the pin, is this correct?

see the last answer on a previous post for BR1 location:

Clarification on low_power example and current consumption

ok. one last question: which one in your picture is the 0-ohm resistor that needs to be removed? thanks

[jasonXu]

AFAIK from the documentation when Vext is ON (GPIO06) the ADC will always read the battery level.

Vext can’t control ADC detection. The two MOS switches are independent of each other. Vext control by GPIO6. GPIO7 control ADC detection(When you don’t remove the resistor of 0R).

When you remove the 0r resistor, the ADC pin on the development board is directly connected to the chip ADC. And you need add the External voltage divider circuit.(Prevent the chip from burning out due to excessive external voltage)

[jasonXu]

looking to a previous answer it seems to me that if I remove BR1 then the ADC pin on the AB01 is completely free and will always measure whatever voltage I place on the pin, is this correct?

so, the anwser is Yes.

[superslot]

and that is the confirmation I was looking for … crysta clear as usual, thanks a lot jasonXu for your help.