AoA (Angle of Arrival) between nRF52833 and nRF52811 frequency deviation

[Quim123]

I am trying to create an AOA link sending a CTE from an nrf52811 (BM833A module) and the receiver with an nrf52833 (bl653 module). Analyzing the CTE detection data, the first 8 reference samples in 2M mode I have a phase error of 30º on average over the 180º that should be detected. In the case of 1M the detected angle is 120º instead of 90º, also 30º of error. To verify the correct operation of the hardware in reception I have used a nrf52833 DK platform as CTE transmitter and in this case, the angle in reception is the desired 90º and 180º. Is there a known frequency offset between the nrf52811 module and the nrf52833? is it only a 30º offset that can be corrected with software, or is it possible to locate the error?

Thank you very much.

JP.

[Simonr]

Hi

I'm not aware of any issue like this. First thing that comes to mind is that there is an issue with either of the crystal oscillators on your nRF52811 module. Does your nRF52811 module have the 32.768kHz crystal on board? If not, try enabling the RC oscillator (in prj.conf of your project).

Are you using the sample projects in the nRFConnect SDK or a custom application? If you're using ours, have you made sure to build the application for the nRF52811 and not the nRF52833?

Also, what central board are you using, an nRF52833 DK with an antenna array?

Best regards,

Simon