sdrangelsrv - how to measure received signal power

Keith Laaks


I am considering using a Raspberry Pi 3B+ with a LimeSDRMini for a portable stations for QO-100 and don't want to have to lug a larger PC along.
Got it working with a screen attached and running the GUI using Ubuntu MATE - so seems to have just sufficient performance. Have not tried TX yet.

If running sdrangelsrv and controlling it via the API, is there an API call available through which to measure the received signal level at a specific frequency, or average power measured between two frequencies? The idea is to have that then display on a small 4 line display.


Edouard Griffiths

Hello Keith,

You can query a report from the channel plugin. Assuming the channel you are using is the only one (index 0) in the only device used (index 0) you send a GET at:
Then the reply should be: 
  "SSBDemodReport": {
    "audioSampleRate": 48000,
    "channelPowerDB": -83.94326782226562,
    "channelSampleRate": 12000,
    "squelch": 1
  "channelType": "SSBDemod",
  "direction": 0
The data you are looking for is in "channelPowerDB". This example is for SSB but nearly all channel plugins use the same syntax.

Best regards,

Keith Laaks

Thanks Edouard!

I will be giving this a spin this weekend.
Thanks for exposing all this functionality via the API- it's really fantastic and enables countless possibilities.

Best Regards