STM32WB55 Bluetooth RF Problem.

[YSN]

1. I have made a custom STM32WB55 Board taking evaluation board as reference except antenna. The antenna used is SMD chip antenna.
2. We have generated p2p server program from stmcubemx and loaded on evaluation board. It is advertise/connect/pair is working fine.
3. But on the custom board the advertise itself is not working. But other peripherals like GPIO/UART/LCD over SPI are working good.
4. I would like know, how debug the RF problem in STM32WB55 chip or are there any check list(voltages ) points to verify to ensure that there is no mistake. We have monitored through spectrum analyzer on the RF pin (using some sniffer) but could not get any spectra ?
5. Is there a way to simply generate some CW frequency from the chip and test the RF path as well.

[Mike_ST]

Hello,

There is a tool called STM32CubeMonitor-RF, please have a look.

https://www.st.com/en/development-tools/stm32cubemonrf.html

[YSN]

Okay thanks, But can you also tell if the FUS is mandatory on any new chip assembled ?

Or we can simply load stack and application should be good enough ?

Also do you have any suggestions for HW verification guidelines etc ?

[Mike_ST]

>> But can you also tell if the FUS is mandatory on any new chip assembled ?

In theory, there is already a FUS version inside the chip. So flashing the stack should be enough.

But, if you mean whether you absolutly need to update the FUS at production time, I don't have enough information to answer.

There is a new FUS version from time to time, and you maybe need to monitor what version gets delivered inside the parts you get.

[Mike_ST]

>> I have made a custom STM32WB55 Board taking evaluation board as reference except antenna.

>> Also do you have any suggestions for HW verification guidelines etc ?

Check you didn't forget to take something from the desgin of the evaluation board.

Check signals, and what's different from the eval board.

Check power lines... etc...

[YSN]

Yeah, verified each pin voltage as per EVK.. everything seems to be good except RF out

That is why worried about generating some waveform and to ensure if RF is at least responding.

[YSN]

@Mike_ST​ I have used STMCubeMonitorRF for generating Fixed frequency, It is not working with custom board. Where as am able to see on EVB. ? It looks definitely HW problem. I have already tested with two or more boards, Any crystal calibration is required ? if so how to do that ?

[WPARK.1]

Dear YSN,

Hello, YSN. Actually, I am having exactly an identical probelm with you.

For my design, I used MLPF-WB55-01E3 as a passive filter and M830520 as a ceramic antenna.

According to my board testing, other LEDs and USB CDC are all fine which means that GPIO and chip setting is correct. Therefore, when I uploaded P2P server, I can see

"Wireless Firmware version 0.0.0

                    Wireless Firmware build 0

                                 FUS version 1.2.2

 SHCI_SUB_EVT_CODE_READY - FUS_FW_RUNNING" from my terminal program. But, I cannot connect BLE with my mobile phone.

As a result, I believe there is something wrong with my design (HW only RF part). Did you solve the problem?

If yes, please share me or recommend me any solution.

Thank you for reading.