Low-cost 433 MHz door/window reed sensors get open source firmware

Rectangular printed circuit board, a bit bigger than a AA battery, also has a AA battery slotted onto it

It’s an unfortunate reality these days that if you see a cheap piece of consumer electronics, there’s a good chance its only cheap because it’s designed to lock you into some ecosystem where you’ll either end up paying a subscription, or worse, have your personal information sold behind your back. One of the best tools we have against these sort of anti-consumer practices is the development of open source firmware replacements that put control of the device into the hands of the community, rather than a corporation.

Now, thanks to the work of Jonathan Armstrong we have such a firmware for the 433 MHz magnetic door and window sensors that you can pick up on AliExpress for $4 USD a piece. The new firmware not only ensures you can use these sensors with a wide array of receivers, but adds a number of new features over their stock configuration.

The open source project includes some recommendations for a Sonoff bridge, flashed with Tasmota or ESPurna firmware, which allow these sensors to appear as switch entities in Home Assistant. There is also a link at the bottom to the sensor market page on AliExpress.

See https://hackaday.com/2023/01/08/low-cost-433-mhz-door-sensors-get-open-firmware/

#technology #opensource #reedswitch #homeautomation