Data receiver

rtl_433

Hundreds of small embedded devices receive small chunks of data transmitted at 433.92MHz from a sensor somewhere. Weather sensors commonly send data to a receiver located somewhere dry and warm, whereas different home automation systems can use the data from a variety of different temperature sensors to do things like stop pipes from freezing, warm a house before you get home, or open the gates as your car approaches. Home automation is one of the biggest consumers of this kind of technology, but every vendor seems to implement its own set of protocols for its own set of hardware, making it very difficult for those of us trying to implement an open source system that may integrate some of their kit.

Thanks to much of this hardware being built around the Realtek RTL2832 receiver chip, a chip that can also be found in many common USB DVB digital television receiver dongles, all that was needed to turn those proprietary dongles into open source data sources was an open source implementation of their driver protocols. This is exactly what rtl_433 does. It supports nearly 100 separate devices, from car key fobs to oil tank level monitors, and grabs the data those devices are broadcasting. With a simple rtl_433 command, that data can be output to your Linux command line and, from there, transformed into almost anything. With the Domoticz home automation system, for instance, you can very easily execute a read command at set intervals and use this to update a virtual sensor within a home automation system, triggering an alarm, perhaps, or sending a new heating oil order. These small tools are the epitome of what's made Unix/Linux successful, and it's the best thing about open hardware in general.

Project Website

https://github.com/merbanan/rtl_433

Like a pen in the hands of an author, the humble rtl_433 utility can take simple readings and transform them into smart home automation controllers.

Bash alternative