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I wrote a tiny program to help test the tire pressure sensors on my car. You can receive signals from these sensors using a cheap SDR dongle and a program calle
by prova_modena 5y ago
I wrote a tiny program to help test the tire pressure sensors on my car. You can receive signals from these sensors using a cheap SDR dongle and a program called rtl_433. However, out of the box the process is bit messy and requires tweaking and interpretation. So I wrote a bash script that wraps rtl_433, guides you through the process in an easy-to-understand way and summarizes the results.
A program like this is not full automation, but it greatly reduces the cognitive overhead of doing this task. Now when I suspect a sensor is bad, I can just pull out the script without having to get back up to speed on how to orchestrate the component programs and interpret the results. It's like having a well-designed jig for a woodworking task, hanging on the wall for later use.
Writing tiny programs like this is really satisfying because the scope is small enough that I can carefully consider all decisions. I spent a lot of time reading through guides and code samples, considering dependencies vs pure bash, understanding shellcheck warnings, and making the code conform to a style guide. All not strictly necessary to achieve the goal, but I learned a lot and take satisfaction in a small, but refined result.
- el_benhameen 5y agoDo you have the code for this living anywhere? I think I have a bad TPMS sensor in one of my tires and it sounds like your tool would be immensely helpful in figuring out which one.
- prova_modena 5y agohere's the code: https://github.com/rouyng/tpms-helper https://github.com/rouyng/tpms-helper so far I have only tested it with Toyota sensors, so YMMV when used with other sensor types as I'm not sure if the rtl_433 output will be the same. I also wrote a blog post when I first figured out how to test the sensors with rtl_433, before I wrote the script. probably useful for background information: https://www.r-c-y.net/posts/tpms/ https://www.r-c-y.net/posts/tpms/
- pcthrowaway 5y agoThank you for sharing. I have a Prius and the tire pressure alert is on even though all the tires appear fully inflated. Is there a way to determine which sensor is detecting low pressure?
- el_benhameen 5y agoIncredibly helpful, thank you! I actually just found your blog post on this. I happen to have a 2008 Corolla with the same issue, so my guess is that the sensors are very similar.
- ajolly 5y agoFeed rtl_433 into home assistant, can easily create alerts based on the output.