I've been doing a bit of playing with
merbanan's rtl_433, which uses the rtl_sdr code to decode signals from 433 Mhz ISM devices that mostly use On-Off-Keying.
So far I've been working on decoding
- Lacrosse TX-7 temperature and humidity sensors, same protocol as TX-3, TX-6.
- DSC wireless security contacts (door/windows, smoke and carbon monoxide detectors)
There is a lot I've learned from playing with the devices using rtl_433 and digging into the code. I need to write it up because there are almost no instructions.
I've posted the
LaCrosse code to github and submitted a pull request to merbanan/rtl_433.
I'm successfully decoding the DSC contacts using a separate Python script that parses the debug output from rtl_433. I need to write a new pulse decoder for rtl_433 in order to handle the DSC protocol as it's a little different than other pulse or distance coded signals. It doesn't send anything for a zero (0) bit, so there can be long periods (up to 8 bit slots) of no signal.
For more info, contact me if I haven't posted here or to github.
Update: 2015-01-11, merbanan processed a whole bunch of pull requests, including mine, so the LaCrosse TX-7 support is now in the main
merbanan/rtl_433 github repository.
I haven't pushed any code for the DSC sensors yet. I have to decide how I want to do the decoder and call back yet. Anything I push will probably be only be in
rct/rtl_433 for a while as it is likely to be experimental.