Things you can do with a Software Defined Radio (2024)

Receiving 433Mhz sensor data using rtl_433[0] with an RTL SDR was a lot of fun when I started doing it last year. There's MQTT output if you want to send it to Home Assistant, et. al., as well as simple text output to stdout. It was great fun seeing my neighbors' sensors, tire pressure sensors in passing vehicles, etc.

There a ton of devices that use 433Mhz. You can also extend rtl_433 pretty easily.

[0] https://github.com/merbanan/rtl_433

I was hoping to find more devices around me which use 433. Apparently my neighbors don't have any 433MHz devices.

I'm spoiled. One of my receivers is on a second story and has great line-of-sight to a bunch of houses and a parking lot (where I assume I get a lot of my TPMS "hits").

I was able to read some data from my electric meter, but the good stuff is encrypted.

What I was _really_ hoping to read was my water meter. It transmits so infrequently, though, so it's hard get much of anything or even know if you're successfully receiving something more than noise.

A lot of the 433/915 band devices you can pick up with rtl_433 seem to be much more bullet proof and have longer battery life than equivalent WiFi and Zigbee devices too. Building new protocol decoders for rtl_433 also surprisingly isn't too bad either. One of my favorite ones is the water meter decoder which has saved me a lot of money when I've had irrigation water leaks and not noticed them (but saw conspicuous usage patterns reported).

ive got ~15 deployed sensors/transmitters and I haven't touched a single one in 14 months since initial setup. its super reliable if you can get your receiver/antenna somewhere that works well.

WAY cheaper than the other options too.

I've been going down this rabbit hole, there are two alternative options if you're looking for a side project, 1 is "ai on the edge" (Google it it's a pretty cool project), which is basically an esp32 + camera that takes a photo of your meter on a regular basis and OCRs the data, option 2 is (and I'll be trying this this week) to get a magnetometer hooked up to an esp32 to read the little magnetic pulses the impeller (in my case) makes (which is how the meter hardware they have reads it anyway), can have calibration difficulties but will be so cheap, there are also existing esphome projects for this.

They replaced my older style meter, the kind that you have, with a Sensus Iperl.

https://www.xylem.com/en-us/products--services/metrology-equ...

I know that it has a radio, but it might only transmit when it receives a signal from a vehicle driving down the street.

Oh, wow, didn't know that tech existed, and no display either? Both my suggestions don't work then i guess : -(