STM32WB55RG BLE not advertising when connected to 5V adaptor

[yeji_jang]

Hello, ST Community

I’m currently working with the NUCLEO-WB55RG board to enable BLE communication.
Initially, BLE advertising worked perfectly when the board was powered via USB (connected to a PC or 5V Adaptor).

However, now BLE advertising do not start, when I power it via USB - 5V adapter. 

The 5V adapter is not the issue — it’s a stable power source rated at 5V / 3A.

I powered using CN15(ST-Link 5V-usb) in both cases before and now.

System setup

• Board: NUCLEO-WB55RG

• Expansion board: X-NUCLEO-NFC08A1

Initialization sequence in main.c:

int main(void)
{
HAL_Init();
MX_APPE_Config();
SystemClock_Config();
PeriphCommonClock_Config();
MX_IPCC_Init();
MX_GPIO_Init();
MX_RTC_Init();
MX_X_CUBE_NFC6_Init();
MX_RF_Init();
MX_APPE_Init(); // BLE initialization
NFC08A1_LED_Init();
rfalInitialize();
}

When I toggle an LED for debugging, the program appears to stop or hang inside MX_APPE_Init() when i connect to adaptor for power.

What I’ve already checked

• Linker script verified — .MB_MEM2 section syntax is correct (no extra dot issue). regarding this forum https://community.st.com/t5/stm32-mcus-wireless/stm32wb55rg-ble-advertising-issue/td-p/127368

• The same firmware still runs fine when connected to a PC via USB, but fails when powered by adapter.

Following photo is what I captured at STM32cubeProgrammer after FUS and Wireless BLE Stack update

The board was running perfectly until recently, and it’s unclear why BLE initialization now fails.. (i never edited the code)

I’d be really grateful for any suggestions or checks I could try — even small details or things that might seem obvious.

Best regards,

Yeji

---

Edited to apply source code formatting - please see How to insert source code for future reference.

[Andrew Neil]

Have you tried using the debugger to see where & why it's hanging?

[yeji_jang]

it works well when i connect to PC with USB (ST-Link), BLE advertising does not work when i connect to 5V adaptor via USB at CN15

[Andrew Neil]

So have you tried using the debugger to see where & why it's hanging when you power it from the 5V adaptor?

You'd have to use a separate ST-Link ...

[yeji_jang]

Sorry, I am really new to this board so my response might not be clear...

May I ask where should i connect separate ST-Link when I power the board with 5V Adaptor through CN15, which is also connected to ST-Link in Nucleo-wb55rg board?

Should I power 5V to CN1 (USB_USER) and connect another cable from CN15 to PC?

i don't know where i can connect the separate ST Link to my nucleo board, maintaining 5V Adaptor powered.

I really appreciate your help!

[yeji_jang]

I tried to power the board not with 5V Adaptor, but with VIN with power supply, then it the BLE advertising works well.

However still don't know why BLE advertising not works when i use 5V adpator..

Thank you 

[Andrew Neil]

That should be described in the User Manual for the board, which should be available on the 'Documentation' tab of the Product Page:

https://www.st.com/en/evaluation-tools/nucleo-wb55rg.html#documentation

But it seems to be missing.

Perhaps @Imen.D can help with that?

PS:

But the schematics are available on the 'CAD Resources' tab:

https://www.st.com/en/evaluation-tools/nucleo-wb55rg.html#cad-resources

so you could check from there...