How do you tell which of the 24 channels in nRF connect view RSSI is related to a given BLE signal?

[EdT]

I have the nRF connect application running, but it shows 24 channels, most blue and 3 green. What is the significance of blue vs green? Also, even though I have wifi turned off and Bluetooth turned off on all devices, I am still seeing a bunch of bars, some as high as -52 dBm. What are these signals and, more specifically, if I am running the heart rate monitor on, for example, a dongle, how do I know which of the RSSI bars relates to that device? And, when that app is running, I see LED1 flashing for a while. Then it becomes solid, then it goes back to flashing. Is it transmitting a signal all of the time, or will I only be able to measure RSSI when the LED is flashing or solid?

[Andreas]

Hi,

 

The green channels are the frequencies that in Bluetooth Low Energy are used as advertising channels and the blue as data channels. All are generally used in BLE unless the channel map is modified by the central.

 

The RSSI viewer measures the energy level received, it does not distinguish between BLE, other protocols or just noise. This means that there will be a fair bit of noise, i.e. bars jumping up and down, based on the interference and noise level in your area - even if you have turned off your wifi, your neighbour might not have turned off his/hers.

 

Best regards,

Andreas