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Associate II
April 20, 2026
Question

UART of NUCLEO-WB09KE UART signal no found

  • April 20, 2026
  • 7 replies
  • 331 views

Dear ST team.

 

I am testing UART of NUCLEO-WB09KE with the board [STM32WB09 Nucleo-64 board (MB1801 and MB2032)]

I Set UART1 PIN PB4, PB4 with the source attached[100ms period tx send ].

I am checking CN3(23), CN4(35) but no signal shown.

Is there anythn

JunkgyuHan_1-1776679564607.png

JunkgyuHan_2-1776679632381.png

 

JunkgyuHan_3-1776679789669.png

 

 

 

7 replies

ST Technical Moderator
April 20, 2026

Hello @JunkgyuHan ,

Check the pins mapping. Try using PA1 (TX) and PB0 (RX) for UART communication.

In order to give better visibility on the answered topics, please click on 'Best answer' on the reply which solved your issue or answered your question. Thanks
Associate II
April 21, 2026

Dear @Imen.D 

Thank you for support.

I have tried to check the pin [CN7:5(PB4) and CN7:6(PB5)] with same code, but still not any signal seems.

(Take off SB21 and SB18)

JunkgyuHan_0-1776737381436.png

 

I also tested with two origianl example codes for [NUCLEO-WB09KE] : <UART_Print>,<UART_HyperTerminal_IT>

(All Uart1 PB0:PA1)

I took Pin CN3:14 to check the waveform, but nothing shown.

JunkgyuHan_1-1776737402573.png

Please Help if anything I missed.

 

ST Technical Moderator
April 29, 2026

Hi @JunkgyuHan ,

Did you follow Laurent's recommendation? Were you able to resolve the issue?

If so, please share the final solution you found and mark this thread as answered. This helps other community members who have the same issue to find the answer faster.

 

In order to give better visibility on the answered topics, please click on 'Best answer' on the reply which solved your issue or answered your question. Thanks
Laurent LOUAZON
ST Employee
April 21, 2026

Hello, 
Agree the best is to start from an original code from ST such as <UART_Print>.
I just built and flash it inside Nucleo-WB09.

I am able to connect with an hyperterminal (picture below) set as explained in readme file of this example (Data Length = 7 Bits, One Stop Bit, Odd parity, BaudRate = 115200 baud, Flow control: None)

LaurentLOUAZON_0-1776785345389.png

Are you able to have the same?

Also when you mention you do not see signal of CN3:14.
Are you talking about CN3:14 of MB1801?
Be careful, on MB1801, PA1/PB0 can be accessed on CN3.35 and CN3.37

Although, keep in mind it might be useful to set JP1 jumper on "boot" position for flashing STM32WB09 (especially if you already have an application running with low power). Of course, after flash, this jumper must be set in "user flash" position.
Regards
Laurent

Associate II
April 30, 2026

Thanks @Laurent LOUAZON  @Imen.D 

Still have problem, (on MB1801, PA1/PB0 can be accessed on CN3.35 and CN3.37)

Nothing shown with <UART_Print> binary.[stm32cubewb0-v1-4-0\STM32Cube_FW_WB0_V1.4.0\Projects\NUCLEO-WB09KE\Examples\UART\UART_Printf]

 

But I found something.

with <BLE_Peripheral_Lite>[C:\cgu\ble\stm32cubewb0-v1-4-1\STM32Cube_FW_WB0_V1.4.1\Projects\NUCLEO-WB09KE\Applications\BLE\BLE_Peripheral_Lite]

There is uart output on CN3.37

JunkgyuHan_0-1777541896238.png

messege is "Success: aci_hal_set_tx_power_level command ....."

 

Laurent LOUAZON
ST Employee
April 30, 2026

Hello,

Just tested as well BLE_Peripheral_Lite and I can see below message on CN3.37

LaurentLOUAZON_0-1777551700079.png

So if this works on your side, no reason, this should not work for UART_Printf FW.

 

Have you used our default binary provided for BLE_Peripheral_Lite FW or did you rebuilt it?
I guess you had no choice to rebuilt UART_Printf as we do not provide default binary for this one.

Laurent

Associate II
May 7, 2026

@Laurent LOUAZON  It is same as I have got.

I tested with rebuilt binary.

 

eb3d8015-8fd9-4031-afbf-78d23e261724.jpg

949988ff-e84c-4790-a866-6bd2194b8b12.jpg