Help me rtl kenobi?

[Tony Giaccone]

I'm hoping you all can give my set up a quick review and point out where I'm going wrong. I'm a radio newb. 

Setup:  Acurite 5 in 1 weather station, out side about 50ft from the house. Raspberry pi, with NooElec NESDR Mini 2 SDR usb dongle and an NooElec ADS-B Discovery 5dBi (High Gain) Antenna. 

I start it with this command: 

$ rtl_433 -C si -M level -R 40 -Y level=-30 -F json

I'm getting data, but it's really irregular,  over 10 hours, I got like 70 observations.  I don't know how frequently the acurite broadcasts data, but my guess is somewhere between 30 sec and a min.  So 70 is pitiful. 

A typical observation looks like:

  {
    "time": "2022-03-16 21:17:46",
    "model": "Acurite-5n1",
    "message_type": 49,
    "id": 1079,
    "channel": "C",
    "sequence_num": 1,
    "battery_ok": 1,
    "wind_avg_km_h": 4.311,
    "wind_dir_deg": 67.5,
    "rain_mm": 44.958,
    "mic": "CHECKSUM",
    "mod": "ASK",
    "freq": 433.92,
    "rssi": -12.144,
    "snr": 19.208,
    "noise": -31.352
  }

[Christian Z.]

 -Y level=-30

That's dangerous, yoiu need to be sure that is the actual level seen and it stays there. Better use

-Y autolevel

[Tony Giaccone]

Ok, so I started out with auto level, but found I didn't get any data, so I set it explicitly.  I"ll run as you suggested again, 

$ rtl_433 -C si -M level  -R 40 -Y autolevel  -F json

And I got this:

Estimated noise level is -17.3 dB, adjusting minimum detection level to -14.3 dB
Estimated noise level is -19.2 dB, adjusting minimum detection level to -16.2 dB
Estimated noise level is -20.9 dB, adjusting minimum detection level to -17.9 dB
Estimated noise level is -22.4 dB, adjusting minimum detection level to -19.4 dB
Estimated noise level is -23.8 dB, adjusting minimum detection level to -20.8 dB
Estimated noise level is -24.9 dB, adjusting minimum detection level to -21.9 dB
Estimated noise level is -25.9 dB, adjusting minimum detection level to -22.9 dB
Estimated noise level is -27.7 dB, adjusting minimum detection level to -24.7 dB
Estimated noise level is -29.0 dB, adjusting minimum detection level to -26.0 dB
Estimated noise level is -30.0 dB, adjusting minimum detection level to -27.0 dB
Estimated noise level is -31.1 dB, adjusting minimum detection level to -28.1 dB
Estimated noise level is -32.2 dB, adjusting minimum detection level to -29.2 dB
Estimated noise level is -33.3 dB, adjusting minimum detection level to -30.3 dB

of course I'm not getting data very often, so it could take a while, to see if this is working, only time will tell... 

[Tony Giaccone]

| That's dangerous....

Can you explain why it's dangerous? What could be the consequence that would lead to danger?

On Thursday, March 17, 2022 at 7:32:23 AM UTC-4 Christian Z. wrote:

[Christian Z.]

Ok, "fragile". Dangerous to assume it would work and keep working ;)

But the levels you posted indicate a good clean band with at that level, so reasonably safe, maybe.

If you have a recent (git) version of rtl_433, then you can also use the rtl_tcp pass-through (-F rtl_tcp) to watch live data from e.g. Gqrx or any other SoapySDR-enabled UI using this driver https://github.com/pothosware/SoapyRTLTCP