Mysterious 433MHz device via RFXCom

Morning all,

My RFXCom based setup for 433MHz has been working great, and I recently enabled debug output whilst I was trying to catch a new sensor. I’ve since noticed in my logs that I have a seemingly rogue sensor transmitting with a new ID every 30 seconds or so. It only appears when the RFXCom is configured to receive the Oregon Scientific protocol.

I live in a fairy remote location, so I’d be surprised if it was someone elses device. It’s not my weather station either, and everything else is accounted for. I have automatic_add: enable for the sensors class with rfxtrx, but nothing is being added.

What confuses me is that it’s a new ID every time, so even if I add it to the config, it never reappears.

There’s a sample of debug output at if anyone could shed some light on it!

You don’t happen to have a radio scanner or SDR radio, right?
That’s what I would use to check if the signal is actually existing (and it’s not imagined by the RFXcom or locally generated)…and then maybe pinpoint its location.

I am firing up rtl_433 at this very moment :slight_smile: More to come in the next 24 hours

Well, you are fully equipped :smiley:

Well, rtl_433 doesn’t understand what it is, but the analysis output says…

Detected OOK package    @ 2017-12-26 22:18:58
Analyzing pulses...
Total count:  110,  width: 32575                (130.3 ms)
Pulse width distribution:
 [ 0] count:   23,  width:   240 [238;246]      ( 960 us)
 [ 1] count:   86,  width:   118 [116;121]      ( 472 us)
 [ 2] count:    1,  width:   342 [342;342]      (1368 us)
Gap width distribution:
 [ 0] count:   86,  width:   125 [123;129]      ( 500 us)
 [ 1] count:   23,  width:   248 [246;250]      ( 992 us)
Pulse period distribution:
 [ 0] count:   20,  width:   366 [364;371]      (1464 us)
 [ 1] count:   76,  width:   244 [241;247]      ( 976 us)
 [ 2] count:   13,  width:   489 [486;491]      (1956 us)
Level estimates [high, low]:  10648,     47
Frequency offsets [F1, F2]:   -9424,      0     (-36.0 kHz, +0.0 kHz)
Guessing modulation: Pulse Width Modulation with startbit/delimiter
Attempting demodulation... short_limit: 179, long_limit: 291, reset_limit: 251, demod_arg: 2
pulse_demod_pwm_ternary(): Analyzer Device 
bitbuffer:: Number of rows: 2 
[00] {109} 80 00 00 e0 99 43 00 52 90 12 40 00 11 88 
[01] {0} : 

It might be my Alevel 0214 LPG tank sensor. As far as I can tell, though, that sensor isn’t supported by RFXCom at all. It might be the fallout of it trying to interpret it. I’ll trudge out into the snow tomorrow to see if there’s any correlation.

Even if it is the same device… I’m still in ‘undecoded land’ :slight_smile: I do have a bunch of SDR captures from it [1] a few months ago. But I haven’t been able to figure them out yet. Will see.


Use RFXmngr to check the packets received.

The packets starting with 115A01 are from an OWL device:
Packettype = ENERGY
subtype = ELEC2 - OWL CM119, CM160
Sequence nbr = 116
ID = E452 decimal:58450
Count = 4
Instant usage = 1110 Watt
Signal level = 7 -64dBm
Battery = Low

Awesome, thank you @b_weijenberg - it was my OWL energy sensor that was providing those messages.

100% down to my lack of understanding what the Pkt_id is. I already had my sensor as 115a0100e452000000046600006462cb3e79 so I didn’t understand where all these ‘different’ IDs were coming from.

That just leaves me with a pile of SDR captures from my LPG sensor now :slight_smile: rfxmgr doesn’t seem to report anything when the LPG sensor flashes its ‘transmit’ LED. Something for another day!


I have also some OWL energy sensors, did you find a way to add it to your Home assistant in stable way ?
If yes could you share your config ?


Hi @mapo, welcome!

I do use Owl sensors, but it’s been a while since I set it up. My config contains this…

- platform: rfxtrx
  automatic_add: True
    # Old 115a0100e452000000046600006462cb3e79:
      name: Electricity

This just needs the RFXCom to be configured to receive Owl messages, and you’ll see your ID in the logs I think… or maybe in the list of devices in Home-Assistant these days. After that, you can add the ID under devices: as above.