I can't read more then 8 bytes long attribute value from BLE characteristics with P-NUCLEO-WB55.USBDongle from STM32WB55. It might be a bug?

DImre.1 · ‎2021-09-24

Details:

I have 4 characteristics in my service. I can read the first 3 characteristics with ACI_GATT_READ_USING_CHAR_UUID command (see AN5270 reference manual) in STM32CubeMonitorRF. For the 4th I got timeout and after that I can't read anything anymore. The difference is that first 3 characteristics attr values are 1,2 and 3 bytes long, while 4th is 8 bytes long. Looks like it freezes the dongle because if I implement these commands in Python (using instead of STM32CubeMonitorRF) it behaves the same way, however, with a third party Android BLE sniffer app I can read even the 4th characteristics attr value without any problem.

Is it possible that there is a setting which needed to be set in the dongle? (E.g. maximum bytes per attribute value or similar...). Or any useful advice?

Thanks,

David

DImre.1 · ‎2021-09-24

Additional info: while the 3 characteristics have read,write properties, the 4th char has read, but write without response property. I don't think it influences the read feature, but who knows that...