Low range for Round-Trip-Time distance estimation (nRF Connect 1.9.1)

[tonivuc]

Hi

We peformed some tests of the RTT sample code provided with nRF connect 1.9.1 a few weeks ago (nrf/samples/bluetooth/nrf_dm) and only got about 132 meters of Line of Sight range on it before it stopped providing distance estimates and just returned 0 as the distance. Used two nRF52833 DKs.

Using another custom RTT implementation (with transmit power of 8 dBm) we got a range of over 800m (didn't have long enough LoS to test max) 

Maybe the transmit power of the sample code was set low? I see how it can be set in the API documentation as tx_power_dbm but I can't see that it is being set in the example code? In that case I am wondering, what is the default dBm for the example code?

[Kenneth]

The range for RTT is about the same as for normal Bluetooth communication. Range accuracy may reduce at longer distance. Default output power I assume is 0dBm if nothing else is done, at least that have been the case historically.

Kenneth