Custom board, STM32WB55, stack 1.4.0 Operating at low voltages (2.5V-3.0V), the BLE disconnects. Not a BOR reset, because the main microcontroller follows normal execution. Is there a different BOR for the BLE micro ?

[Remi QUINTIN]

First of all, I would recommend you move to the latest Cube WB FW package v1.12.

Then there is only one BOR control which only monitors the VDD supply. So, this is not linked to one core or another.

The BLE disconnections can be due to issues on the other devices it was communicating with.

Otherwise, I do not see any reason why such voltage level would lead to misfunctioned BLE core and RF block.

[rbenv.3]

Yes, I planned to move to latest version.

I found another issue, I didn't found it already written.

It is related to ADC readings, ST recommends turn off SMPS step-down mode before

ADC read, and turn it on after reading, due to accuracy.

I have some sensors I read on main loop, at very high speed, and this caused the BLE

to have bad behaviour, and even stop to advertise.

I removed the "turn off and turn on SMPS step-down mode" from ADC, and BLE was on normal operation again.

Maybe you know something about this problem, but it is new to me