Tx Settings - NRF21540/NRF52840

[Chandu@1996]

Hi,
I'm using NRF21540-DK board to test hci_pwr_ctrl example. My FEM module can boost upto +21 dBm. How to correlate the tx power of radio peripheral(NRF52) and fem module(NRF21540). The output logs are given below.

And also CONFIG_BT_CTLR_TX_PWR_DYNAMIC_CONTROL=y. So I'm thinking this will take care of runtime tx power settings adjustments. Whether this will take care of Tx power of NRF52 & amplifier NRF21540? If not, should I make additional configuration changes to improve the tx gain settings of amplifier-NRF21540?

[Bendik Heiskel]

Hi,

The MPSL FEM driver will automatically calculate the output power of the SoC and the FEM gain to get the desired output power.

The reason you are not seeing higher output power is because the sample by default is configured to only have a maximum of 4dBm output power.

If you modify the txpower array to use higher output powers you will get more than 4dBm.

 

Best regards,

Bendik

[Chandu@1996]

Thanks for the input. I was able to see the power range from 21 dbm gradually getting dropped to -30 dbm for every 5 seconds.