I've got an RTL-SDR radio listening on 433Mhz near a public parking lot and I can definitely see the comings and goings of individual cars. While I'm sure ALPRs are taking over any TPMS-based surveillance there's definitely a risk there.
Aside: I'll never get another chance to share this, so please forgive the "humor".
Once my wife was driving, with me as her passenger when, the car's TPMS indicator came on. She was concerned and said "There's this 'TPMS' warning light here. What does that mean?".
Without even thinking I said "That probably means something." Likely the greatest accidental fitting of words to an initialism I've ever made in my life.
That's the stuff! I've got it doing MQTT into Home Assistant at my house, and CSV into a pipe to a Python script for a commercial temperature monitoring and alerting app. The commercial app is the one that happens to be near a parking lot, but I also periodically get cars showing up on Home Assistant too.
rtl_433 has been great. The ability to capture unknown-to-it signals and build decoders on the command line is really nice. I've got some cheapie driveway motion sensors that I built a decoder for. It was exceptionally easy and all the config was runtime.
rtl_433 is awesome. You can even read your neighbors weather station and send that to Home Assistant using MQTT. It's worth investing in a decent antenna tuned to the ISM frequency (I use a center fed dipole, works great).
And of course there are cheap sensors you can find online for your own temperature probes.
Aside: I'll never get another chance to share this, so please forgive the "humor".
Once my wife was driving, with me as her passenger when, the car's TPMS indicator came on. She was concerned and said "There's this 'TPMS' warning light here. What does that mean?".
Without even thinking I said "That probably means something." Likely the greatest accidental fitting of words to an initialism I've ever made in my life.