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(...) ?

[_RK_]

Were you able to find a solution to this ?

[Carl Richard]

Hi!

As mentioned below the fix won't be available before the next major NCS release. In the meantime the Zephyr LL must be used for this functionality. 

Best regards,
Carl Richard

[_RK_]

Hi Carl,

sdk-nrfxlib/CHANGELOG.rst at master · nrfconnect/sdk-nrfxlib · GitHub As mentioned here, this issue probably has been already fixed and available on the master branch. 

• Fixed an issue where "HCI Read RSSI" would always return a Command Disallowed (0x0C) error code (DRGN-15310).

I tried to pull the master branch and build the hci_uart, but it's failing to build as follows, can you suggest any way to fix the includes for this build?

2> Compiling ‘entropy_ll_softdevice.c’
3> Compiling ‘entropy_cc310.c’
2> C:/Users/u1/ncs/v1.5.1/nrf/drivers/bt_ll_softdevice/entropy/entropy_ll_softdevice.c:12:10: fatal error: sdc.h: No such file or directory
2> compilation terminated.
3> C:/Users/u1/ncs/v1.5.1/nrf/drivers/entropy/entropy_cc310.c:20:10: fatal error: nrf_cc3xx_platform_entropy.h: No such file or directory
3> compilation terminated.
Build failed

[Carl Richard]

Hello!

Great. I stand corrected! Please open a new ticket regarding the build failure and we'll assist you there.

Best regards,
Carl Richard

[_RK_]

Hi Carl,

I was able to build it by pulling latest from main branches of both /nrf and /nrflib and as well as updating the west to v0.10.1 from v0.9.x.