STM32G071R8T6 GPIO - input issue on PA4

[MPF]

Hi,

We have a custom board with a STM32G071R8T6TR, PA4 is configured as input but it does not work.

All other inputs on the boards are working correct but PA4 is a problem.

If we configure PA4 as an output it works fine, we toggle hi/lo, we have checked IDR for PA4 and the IDR does not change which is a problem, it does that when we toggle PA5 and PA6 hi/lo the IDR for PA5 and PA6 change.

If PA4 is configured as input and we change input hi/lo there is no change in IDR either.

We have cheked MODER is correct.

What do we miss here or could this be a defect STM32 MCU ?

Kind regards

Morten

[waclawek.jan]

Sounds much like hardware damage.

Do you have a second board, perhaps a Nucleo?

JW

[AScha.3]

Hi,

did you check real connection to pin exists ?

Try re-solder pin, maybe has bad solder joint.

(Funny is: if you check with DMM or scope, pressing on the pin is enough, to see: is ok.

But is not - as soon, as you no more press on the pin ! )

[MPF]

Hi Jan,

I think we should buy one, tested code and verified registers on STM32F411 nucleo, it works fine.

BR
Morten

[MPF]

Hi AScha.3,

Please read my description, IDR does not change when we configure as output and toggle PA4 hi/lo, IDR does change when we do that on other pins PA5, PA6.

Kind regards

Morten

[waclawek.jan]

Just to be sure:

> If we configure PA4 as an output it works fine,

this means, that you set PA4 as GPIO Output toggled it, and measured the output using logic analyzer/oscilloscope, correct?

JW

[MPF]

Hi JAn,

Yes this is correct.
So when PA4 is configured to output  and is set to 0 we read IDR as 0 - this is ok.

When we set PA4 to 1 we still read IDR as 0 even though we see 1 on the oscilloscope. 

If we do the above on other pins like PA5 and PA6 this works perfect.

Kind regards

Morten

[waclawek.jan]

Assuming this is a minimal code doing nothing else but toggling that pin (i.e. no analog features setup), all clues point to damaged mcu, then.

Note, that PA4 and PA5 are not 5-volt tolerant.

JW

[MPF]

Hi Jan,

We went back to basics and we are running from a very basic program using no other features. :)

Yes the pins work at 3.3V.

MPF

[Richard Li]

Did you check GPIO_LCKR?