What I am trying to accomplish is to establish a connection between an iPhone (device 1) and an NRF52 (device 2), then sniff the data sent between them from a third device (also NRF52, device 3) to get an RSSI. I have the connection part working just fine and I can get RSSI between device 1 and device 2. What I need is RSSI to device 3 without using advertisements or connections (thanks to the limitations of iOS). I can freely exchange any data I need to between device 2 and device 3 (using some wired or wireless connection). Can I somehow sniff the connection and get an RSSI measurement of the signal from device 1 on device 3?
