USART1 (PA9-D8/PA10-D2) on Nucleo-WB15CC not working for serial comms

[saurabhc]

I'm working with a NUCLEO-WB15CC board (MB1641C-01) and am trying to use three independent serial ports for my project.

I have found that the D8 and D2 pins on the board are not working for serial communication. I believe this is due to a pin conflict with the on-board ST-LINK debugger, as a table in the board's documentation shows PA9 and PA10 are routed through jumpers to the ST-LINK (JP5 pins 13-14 and 15-16).

My question to the community is whether D8 and D2 pins are indeed unavailable for user applications due to the ST-LINK routing.

Thank you for your help.

[TDK]

If you disconnect PA9/PA10 from the ST-Link by removing the bottom two jumpers on JP5, they will be available for use. You will, of course, lose VCP functionality.

[STTwo-32 · Accepted solution]

Hello @saurabhc @and welcome to the ST Community. 
As said @TDK, you just have to remove the two jumpers from the JP5. But, for the arduino connectors D2 and D8, they are connected to PB0 and PB5 (not PA9 and PA10) that can not be set as TX and RX pins of USART1.

Best Reagrds.

STTwo-32

[Tesla DeLorean]

The TX from the STM32 doesn't conflict, it can output to two Inputs, ie VCP RX Input, and Arduino Transmit Output.

However you don't want TWO pins driving the STM32 RX, so disconnect one of the sources.  

[saurabhc]

Thanks for all the replies. I'm able to use it thanks to your inputs!