We are in the process of designing the nRF52833 into a product which uses the BLE direction finding capabilities.
I wanted to check if we should avoid using the pins that are recommended for low frequency I/O signals only (up to 10 kHz) because the antenna switching will be faster than this.
There is a Nordic white paper (nWP-036) on direction finding that gives an example of setting up antenna switching for the AoA receiver. This example is for the nRF52811 and it is using Pins 37 to 40 on the QFN48 package (P0.25-P0.28).
The product specification for the nRF52811 includes the following which indicates that pins P0.25 to P0.29 on the QFN48 package should only be used for low frequency I/O but these include the pis being used for antenna switching in the example from the white paper.
Therefore, maybe it is ok to use pins recommended only for low frequency signals for antenna switching. This could be because these pins will only be switching while receiving the CTE part of a BLE packet so will not interfere with normal BLE operation?
