NRF5340 TX transmission power change

[Kaikon]

I am using the Direct Test Mode sample as a starting point (samples\bluetooth\direct_test_mode). I am using NRF Connect SDK Toolchain v2.5.0 and NRF Connect SDK v2.5.0. I want to add increase the TX power to 3dB.

When I set CONFIG_BT_CTLR_TX_PWR_PLUS_3=y in prf.conf, I get the warning:
warning: The choice symbol BT_CTLR_TX_PWR_PLUS_3 (defined at
subsys/bluetooth\controller/Kconfig:292) was selected (set =y), but no symbol ended up as the choice
selection. See docs.zephyrproject.org/.../kconfig.html and/or
look up BT_CTLR_TX_PWR_PLUS_3 in the menuconfig/guiconfig interface. The Application Development
Primer, Setting Configuration Values, and Kconfig - Tips and Best Practices sections of the manual
might be helpful too.

Then, when I try to set CONFIG_BT_CTLR_TX_PWR=y, I get:
warning: attempt to assign the value 'y' to the undefined symbol BT_CTLR_TX_PWR
and the build fails.

How to configure TX transmission power?

[Sigurd]

Hi!

For DTM testing, it's the tester that sets the tx-power.

https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/samples/bluetooth/direct_test_mode/README.html#implementation

[Kaikon]

Maybe I have misunderstood something. I'm trying to turn on the increased voltage for the +3 dBm transmit power.  (like here:  How to get a pointer to the structure of the registers, for setting VREQCTRL? ). In that post, it is mentioned, that "the HCI driver should automatically set the VREQCTRL register if you chose an output power over 0 dBm.". Is this the case also with DTM application? I.e. If I set the TX power over 0dBm, it sets the VREQCTRL register automatically?

[Sigurd]

Kaikon said:

Is this the case also with DTM application? I.e. If I set the TX power over 0dBm, it sets the VREQCTRL register automatically?

Yes, that is correct.

Relevant code line: https://github.com/nrfconnect/sdk-nrf/blob/v2.6.1/samples/bluetooth/direct_test_mode/src/dtm.c#L805