RSSI Monitoring results

[ran]

We are running a trial in an open field, where we connect NRF52840 ( GW ) to an NRF 52833  (Node ).

Distance between the units is around 80 meter , we are using Coded Phy with +8db level and internal Antenna

 

The GW monitors RSSI Level, using "sd_ble_gap_rssi_start(p_gap_evt->conn_handle, 9, 4)", we are seeing major changes in the RSSI, although units are staticly located.

See how it changes between -75 to -96 during the day.

 

Have you see a similar behavior before ? does that make sense for the RSSI to shift so much ?  

[Simonr]

Hi

We haven't done any tests over this amount of time earlier, but it seems fairly reasonable that the RSSI will change over time, as the circumstances and environment will change, even in an open field. This will also be amplified at longer ranges. Are the node and/or gateway moving around at all during this time or are they standing completely still. Is this open field isolated or will there be interferences by I.E. people passing by, nearby traffic, etc.?

If you check out the RSSI viewer application on nRF Connect for Desktop, you can see a visualization of the RSSI per frequency. This will also vary a lot, and is common for DKs as well. If you're uncertain on the antenna, I would suggest doing the same test with two DKs to see if you can see similar values using those as well, but I think this should be as expected.

Best regards,

Simon