Measuring BLE Connection RSSI with NCS

[fgaultier]

Hi Nordic,

I understand that there's a way to monitor the RSSI of a Bluetooth connection using appropriate API from softdevice library. But we are currently developping with NCS SDK. Is there thus a way to implement the same with NCS ? And if not, is there a chance that it will be possible in a future SDK release ?

Best regards,

Franck

[fgaultier]

Hi,

I was not able to have  sdc_hci_cmd_sp_read_rssi(...) command return an RSSI value.

I tried also the Zephyr bluetooth sample hci_pwr_ctl:

• Setting the TX power works fine (on NRF52833 and NRF52832 but with NRF52840 you have to adjust stack size),
• But reading the RSSI (by sending first BT_HCI_OP_READ_RSSI hci command) does not work at all, unless you do not use soft device controller by setting the following config parameters
  • CONFIG_BT_LL_SOFTDEVICE=n
  • CONFIG_BT_LL_SW_SPLIT=y

Does someone have a working sample with  sdc_hci_cmd_sp_read_rssi(...) ?

[Carl Richard]

Hi again!

There has been discovered a bug in our Softdevice controller that results in RSSI reading being disallowed. There are unfortunately no workarounds other than using the Zephyr LL. Apologies for the inconvenience.

Anyway, for proper handling of RSSI reading I suggest to check out how it's done in the hci_power_ctrl sample.

Best regards,
Carl Richard

[fgaultier]

Thanks Carl. This is indeed what I did: starting from hci_power_ctrl sample.

Do you know whether that bug in the Softdevice controller will be fixed anytime soon ?

Best regards,

Franck

[Carl Richard]

Great! I'll check with the developers. 

Edit: I got back that it won't be ready before the next major NCS release at least. 

Best regards,
Carl Richard

[Carl Richard]

Hi again, Franck!

As mentioned by _RK_ a fix is ready in the nRF Connect SDK master branch.

Best regards,
Carl Richard