GPIO PG10 on STM32F769I-EVAL

[PW.1]

This should be straightforward but I cant get it to work. I simply want to control the GPIO output of pin PG10 on the STM32F769I-EVAL board.

I have removed all daughter cards, LCD and the Micro SD card. According to the datasheet, PG10 is connected to SD2_D1 on the micro SD slot, but if the SD card is not installed there should be no issue, right? I have a logic analyzer hooked up to it and the value does not change.

Here is more weirdness. When i toggle GPIO PG6 and PG10 with opposite values, PG10 follows exactly what PG6 does, except the output is not the expected 50% duty cycle square wave. If I only toggle PG6, it is as expected, but PG10 is still following PG6. I have removed SB20, but that should be irrelevant to this behavior. The GPIO thinks it is working correctly though because if i read the value back, i get the expected output.

I have tried this on 2 boards and with minimal software. Any ideas? Is the SD card slot messing with the pin? Did I miss something?

STM32Cube version 5.6.1

Keil uVision version 5.25

Cube project and main attached.

Thanks!

-Phillip

[Tesla DeLorean]

The PG10 in the CN11 silkscreen doesn't match the schematic, it is wired to PG6

This stub would likely cause the MicroSD card to fail. Probe PG10 at the second SD card

https://www.st.com/resource/en/user_manual/dm00276567-evaluation-board-with-stm32f769ni-mcu-stmicroelectronics.pdf

[PW.1]

Thank you so much for this information. It seemed like a hardware issue but I didnt have anything to back it.

Is there a list of open/known issues anywhere? I didnt find one on a quick search. I am surprised something like this slipped through and they haven't rev'ed the board. Makes me wonder what else is wrong... Would explain why the toggle behavior gets weird when I set PG10.

[Tesla DeLorean]

I'm not sure anyone on the forum maintains a list.

Having the odd pin swapped or mislabeled occurs with some frequency. The boards go through revisions or pin changes, as they are adapted for different ICs. Maximizing functionality can be a challenge. A lot of the NUCLEO 64 and 144 have subtle changes between STM32 families.

Can't say I've happened upon this, although I've built SD code for both card slots on the F779 variant.

Generally I go over the manual and schematics, and datasheets to confirm things, especially when things don't seem to work as expected. Tend to be a lot of solder bridge and resistor option on the boards, have to be especially careful if others have touched the boards, or the default settings aren't as expected.

The volume and turn over on the EVAL boards may not warrant a respin

@Imen DAHMEN​ @Amel NASRI​ 

[TDK]

Sounds like you have a solder bridge between PG6 and PG10 somewhere. Or you're not measuring what you think you're measuring.

If IDR reads correctly, the voltage at the actual pin should also be correct.

If you have precise enough probes, you can measure resistance between the PG10 and PG6 pins.

Leave PG6 out of it and only toggle PG10. What happens?

[PW.1]

As @Community member​ said above, the headers are incorrectly shorted together. I thought I did a continuity check before but I probably hit the wrong pins because they are so small and close together. I finally got some nice wires and can verify that PG6 and PG10 are shorted between CN5 and CN11. Probing the real PG10 is going to be another matter, though.