nRF Connect, DTM and Tx power

Question

Hi, 
 we are using nRF52840 and we are now about to start certifications with it, VERY SOON. 
 We are planning to use DTM for that. I am trying to test it with nRF Connect Desktop tool, but looks like I am not able to set the highest Tx powers. 
 I can set +0dBm, +3dBm and +4dBm, but CANNOT set +1dBm, +2dBm, +5dBm, +6dBm, +7dBm and +8dBm. 
 Same result, when I am tryin the firmware with DK. But if nRF Connect Desktop proposes to progam DK, it is flashed with the firmware which support Tx power up to +8dBm. 
 We have built DTM with nRF Connect SDK v2.1.0. 
 Board conf is: nrf52840dk_nrf52840. 
 We have same configuration as in nRF52840DK, i.e. Tx and Rx pins are aligned. 
 How we can take all power levels in use? 
 I really appreciate quick response, as our customer is about to start certifications as soon as possible. 
 Rgds, 
 -Kari-

Simonr · Accepted Answer

Hi 
 Yes, the nRF Connect SDK version of the DTM sample only supports TX powers from -40 to 4dBm, and to get the values above 4dBm you need samples supported by the nRF52840 by default (which the NCS app does not for the time being, it might be implemented in the future). You can use either the Direct Test Mode app in nRF Connect for Desktop as you say, or the nRF5 SDK version of the DTM project. 
 +1 dBm is not a valid configuration according to the nRF52840 product specification, but you should be able to set it to +2 dBm I believe, and I'll ask internally what this could be about, can you provide some details on what happens when you try setting the TX power to +2 dBm on your end? 
 Best regards, 
 Simon