Dynamic Tx power control clarification with FEM-enabled boards

[longo92]

I am controlling the BLE tx power on nRF21540 DB, in the same way as in the example  https://github.com/nrfconnect/sdk-zephyr/tree/main/samples/bluetooth/hci_pwr_ctrl .

I have a question

1. When i set +10dBm or +20dBm the tx power requeste is properly set.
2. When i want to set +4dBm or +8dBm the actual power set is +2dBm and +6dBm respictively. Why i cannot set the exactly +4dBm or +8dBm?

Thank you,

Alessandro

[Naeem Maroof]

Hello,

Looks like the same issue is discussed here: TX Power Fine Gain Control NRF21540

The whole discussion may be more informative.