Low voltage for logic high on Nucleo-G431KB

[JonathanH2L]

Hello STM community,

I have a problem with my Nucleo-G431KB. I am trying to communicate to a sensor device over SPI. The problem I have is that when I use PA5 as SPI1_SCK, the logic high is only 1.4 V instead of the 3.3 V on other pins. When I configure PA5 as normal GPIO output I also get a 1.4 V output. When I use another pin as SPI1_SCK it works as expected. 

I have this problem when the Nucleo is connected to the sensor, but also when there is no load except for the oscilloscope.

At first I thought that it might be a production error, but I have the problem on both of my boards.

Is it normal that this pin has a lower voltage? If so, can I change it somehow?

[Andrew Neil]

Have you checked the board's User Manual and/or Schematics to see if there's anything else on that pin?

[AScha.3 · Accepted solution]

Hi,

from circuit :

seems PA5 connected to PB7 (dont ask me why ! ) ; so open SB7 to get PA5 working as expected.

[Andrew Neil]

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@AScha.3 wrote:

don't ask me why ! 

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Something about "I2C SDA support on ARDUINO Nano A4"

[JonathanH2L]

Thanks!

I put PB7 and PA15 (connected to PA6 for MISO) to the reset state, and now the SPI works.

If I want to use PB7 and PA15 for something else I should open SB2 and SB3, if I see things correctly.