This code is intended to be hooked up to the RF receiver that was part of an old Zeus security system. The system had two wireless PIRs and two wireless door sensors.
I have not been able to find much online about the system. The most detail is this manual (in French) which is of limited use. My system is no longer operational and looking at the board a blown capacitor explains why...
TODO: add some photos of board
So, I've desoldered the RF receiver sub-board and now have it hooked up to:
- A Saleae logic analyser and
- (soon) an Arduino Pro Mini compatible
TODO: circuit diagram
After much trial and error with various iterations I've managed to work out enough of the signal encoding to identify signals from the door sensors.
A transmission appears to be a simple on-off-keying (OOK) 8-byte word along with a synchronisation signal.
The various signals appear to be (as consecutive pulse lengths in microseconds):
- Sync start: 17000, 1300
- Sync (repeated 11 times): 360, 435
- Sync end: 360, 3890
- Resync start: 720, 14775
- Bit zero: 730, 430
- Bit one: 360, 805
- End: >200000
A transmission then looks something like:
TODO: flow diagram
- Sync start
- 11 sync pairs
- Sync end
- 64 bits data (128 pulses)
- 1 parity bit (2 pulses)
The signal will then either terminate with a long pulse or:
- Resync start
- 11 sync pairs
- Sync end
- 64 bits data (128 pulses)
- 1 parity bit (2 pulses)
Then repeat as needed.
The code here provides the main decoding of signal and relies on callbacks to actually get the data and to do something with the result. My intention is to be able to use the same code in an analyzer plugin for the Saleae and on hardware in real-time on the Arduino.
Next thing is to hook up the decoded data to be sent via MQTT to Home Assistant.