bug in ble_dtm.c negative power value

[DaniSi]

Dear,

we have found a strange behaviour when using the DTM in SDK 17.0.2 and 17.1.0. The problem starts from ble_dtm.c:1188 when comparing the parameter value with -30dBm, which is defined as 0xFF and corresponds to -1. This means that all inserted negative values will be set also to 0xFF, except if the value is closer to -40 dBm.

[Kenneth]

Hello,

You should only set values that are supported by the IC, for instance for the nRF52832 that is:
https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.nrf52832.ps.v1.1/radio.html#register.TXPOWER

I assume values that are not supported by the IC can give wrong values. Also, -30dBm value is deprecated and should not be used (I believe if you do set -30dBm the actual output is -40dBm, ref above table).

Kenneth