The direction-finding white paper shows an example for the NRF52811.
I have tried the example to get some NON-softdevice based code and several variations thereof and can't see the added CTE using zero span on any spectrum analyzer.
Our receiver code does not see it either.
Based on the white paper, here is the stripper down version of the code added during the radio initialization after power up and before other radio configurations.I have cheked with a debugger that the registers are set properly.
AoA_NUMBER8US has been set to 3, 4, and 8 without result
NRF_RADIO->DFECTRL1 =
(RADIO_DFECTRL1_DFEINEXTENSION_CRC<<RADIO_DFECTRL1_DFEINEXTENSION_Pos)| (AoA_NUMBER8US<<RADIO_DFECTRL1_NUMBEROF8US_Pos);
NRF_RADIO->DFECTRL2 = 0;//(64<<16) | 64;//(AoA_DELAY_16M<<RADIO_DFECTRL2_TSAMPLEOFFSET_Pos) | (AoA_DELAY_16M<<RADIO_DFECTRL2_TSWITCHOFFSET_Pos);
NRF_RADIO->CTEINLINECONF =
(RADIO_CTEINLINECONF_CTEINLINECTRLEN_Disabled<<RADIO_CTEINLINECONF_CTEINLINECTRLEN_Pos);
}
