this post was submitted on 02 Jul 2023
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I’m not sure how you guys would feel about this… but I have a SDR connected to my Unraid server and found that a neighbor has one of those Acurite 5-1 weather stations that I can pick up on a 433mhz signal, parse the JSON file and added it to my dashboard. If you have a SDR sitting around you could scan your area and see what you get.
I second using an SDR with 433MHz devices. Incredibly reliable and low power.
Been using a nooelec SDR and one of these sensors:
Geevon TX10 Wireless Remote Outdoor Sensor
Never thought of this approach.
So, what is it transmitting? Text? Or some form of numerical data?
I mean, how do I start? 🙂
Each device has its own protocol/payload, but there is a utility called rtl_433 that can decode about 200 of them.
If you're keen on tinkering a bit I would highly recommend going this route as it's a lot of fun and opens the doors to do all kinds of stuff.
Start by getting an SDR. I don't recommend the super tiny ones since they can get really hot (since it'll be running 24/7). I have this one and recommend it as it comes with an antenna etc. Nooelec RTL-SDR v5 Bundle
While you're waiting for that to arrive set up an MQTT broker if you haven't got one running already (the Mosquitto add-on in HA) and install the rtl_433 add-on as well.
From there read the rtl_433 docs to set up a config file to scan for what you want. Out of interest I set mine to rotate through a bunch of common frequencies and let it go for 24h to see what it could pick up. It was quite interesting! Another good way to do this is any wireless device will have an FCC number on it. You can look that up on their website and it'll tell you what frequency it's using and you can have your SDR scan that. If you don't specify any protocols the rtl_433 utility will try everything it knows how to decrypt. This can be CPU intensive especially on a Pi so once you know what protocol it is you can specify it in the config file to reduce CPU load.
Hopefully that's enough to set you down the right path. Happy scanning!
Great summary, thanks
Most people run rtl_433 to decode radiofrequency signals.
https://github.com/merbanan/rtl_433
0’s and 1’s are encoded with increases and decreases of amplitude of the carrier frequency, as in AM radio.
It's really easy. The rtl_sdr software interprets the info and passes out to HA. There's an add-on that scans that info and looks for devices it recognizes, and adds then to HA as a sensor. You'll get weather, tire pressure monitors, and other things.
Yup! In addition to temperature/humidity sensors, I'm also pulling in my gas meter and my home security sensors(I was using a big-name security company, but when my contract was up I kept the sensors installed and tapped into them with my SDR)
I did exactly this as well. Only I bought my own 433Mhz weather sensors. They are cheap and the batteries last for ages.
That's exactly what I did. I also have some indoor Acurite sensors too.. but that weather station is definitely one of the neighbors.