RE: TX Power Level Setting nrf5340 nrf Connect SDK

Marte Myrvold — Fri, 29 Jul 2022 11:02:33 GMT

Hi,

[quote user=""]Do you know if passing a tx power level of 3 with the HCI BT_HCI_OP_VS_WRITE_TX_POWER_LEVEL command will set the tx power level to +3dBm in the nrf5340 radio?[/quote]

Yes, if you are using the SoftDevice controller then you can set the tx power to +3 dBm with the BT_HCI_OP_VS_WRITE_TX_POWER_LEVEL command. The Zephyr controller does not support +3 dBm on the nRF5340.

[quote user=""]What happens if we try to set a power level greater than 3 dBm?[/quote]

Then it will be set to +3 dBm instead.

[quote user=""]Does the get TX power command (BT_HCI_OP_VS_READ_TX_POWER_LEVEL ) return a truncated power level to be reflective of the actual setting?[/quote]

BT_HCI_OP_VS_READ_TX_POWER_LEVEL returns the actual tx power.

If you are curious and want to test this out you can use the Bluetooth: HCI Power Control sample. This sample will change the tx power to the values in the array txp, so you can change the values in txp to test with 3 dBm and above 3 dBm. The sample also reads the tx power with BT_HCI_OP_VS_READ_TX_POWER_LEVEL and prints it. Just add the following to prj.conf:

CONFIG_BT_LL_SOFTDEVICE=y

CONFIG_BT_LL_SW_SPLIT=y

Then build the sample for the net core and build the empty app core sample for the app core to test it out.

Best regards,

Marte