A few years ago I bought an alarm system that works with wireless sensors.
Now I have an openHAB installation running to make my house a little smarter.
Unfortunateley the alarm system is a closed system - not able to interact with openHAB.
The old sensors are installed on a lot of doors and windows and of course I like to reuse them instead of buying new ones.
The sensors have "868 FSK" printed on them. More information I do not have.
I have tried a bit more with "Universal Radio Hacker". And now I think I found the right configuration to decode the signal. I read that 600 is a typical baudrate for FSK. So I configured the URH interpretation module to this value (Samples/Symbol) and here we are!
Window sensor 1:
Window sensor 2:
The signal from sensor 1 is decoded to 349B.4934.926D.3492.49A.
The signal from sensor 2 is decoded to 26D2.6BB4.9269.B492.49A.
The next step is to modify the SignalDuino firmware for the nanoCUL, to receive the same signal.
I did a little research what no I can do with AIRSPY to interpret this unknown signal. I read that the signal can be exported to an audio file. This audio file can be imported by Audacity for example. I played a little bit with both tools but I was not really successful.
But then (by accident) I found URH (Universal Radio Hacker) !!!
In the next step I try to receive a signal with an SDR Dongle and the software AIRSPY (SDR#).
OK, this looks good. I got a signal on 868.475MHz. the two peaks left and right beside the mid frequency is typical for a FSK (frequency shift keying) modulation.
this is an interesting analysis for me, because I have exactly the same alarm system and I was looking for a long time for documentation about decoding 868Mhz .
With your detailed explanations, I arrived at the same result, and was able to decode my windows sensors.
Thank you very much.
I am now interested in the next step, which consists in integrating the state of my windows sensors in Home Assistant. I first did some research around EspHome but I did not find anything very concrete. The only thing that seems obvious to me, is that I will have to use a CC1101 driven by an ESP32, ESP8266 or Arduino. I didn't know SignalDuino, FEHM, or nanoCul interfaces. This way seems very interesting. Have you made any progress ?
Thank you for posting this project! I have always wanted to know more about how to untangle unknown formats, coding schemes and the like. I wasn't aware of the tools you used, so this is really exciting. Good luck in getting these sensors figured out!
Love seeing unknown protocols decoded, and Universal Radio Hacker is an absolutely fantastic tool. Very interested to see how you progress with this project.
Hello,
this is an interesting analysis for me, because I have exactly the same alarm system and I was looking for a long time for documentation about decoding 868Mhz .
With your detailed explanations, I arrived at the same result, and was able to decode my windows sensors.
Thank you very much.
I am now interested in the next step, which consists in integrating the state of my windows sensors in Home Assistant.
I first did some research around EspHome but I did not find anything very concrete.
The only thing that seems obvious to me, is that I will have to use a CC1101 driven by an ESP32, ESP8266 or Arduino.
I didn't know SignalDuino, FEHM, or nanoCul interfaces.
This way seems very interesting.
Have you made any progress ?
Sorry my bad English.
Daniel