Doing a bit of googling I noted that in the USA the X10 RF (Radio Frequency) remotes and sensors transmit a radio signal on 310 MHz - which is one of the frequencies used by garage door openers.
I have two questions:
Does anyone have / can anyone recommend a device that works on 310 MHz that can detect when a garage door opener button is pressed … that can send that the notification to Home Assistant.
If you have such a device, could you test it to see if it can detect the signal from an X10 RF Switch or RF Sensor.
To be clear I am not asking about X10 integrations - imagine that you have thrown away all your X10 modules, the CM11A computer module and the X10 radio receiver.
All you have left is the RF switches and and RF sensors - I want to know if those can be connected to home assistant by detecting the RF signal / it it possible to identify the different unit/house codes of the switches/sensors?
Note: I suspect it is possible, because the modulation for the RF is the same as that typically used for IR remotes (its just they are transmitted via RF not IR) and the X10 tech is old, so it has likely been re-used by garage door openers.
Chances are very slim.
Remotes for garage openers nearly always use rolling codes, so without knowing the algorithm for the rolling codes you will never be able to send or interpret the signals correctly.
Rolling codes makes sure that if press one button, like a 1000 times or more none of the send codes will be the same.
I just ran another test, I have the X10 UR78A remote - whats special about that remote is that it has both IR and RF transmitters. Specifically when you press a button to transmit the RF signal, it also sends the same signal to the IR LED.
Hence if I point the the remote at a webcam (webcams can see IR) and press the ON button I see the IR flash (on the webcam) and the RF signal is picked up / turns on a light - in short it is the same signal (just two different transmission mediums IR + RF).
I have a BroadLink RM4 Mini on order (arrives Monday) so when that gets here I can point the remote at it and see if it can differentiate the different codes.
Ideally I would prefer a dedicated device (if someone has a recommendation).
However assuming the RM4 can identify the codes / send them to HA. All I need to do is cannibalize the RF receiver circuit from an X10 RF receiver and wire it up to an IR LED then I can use any IR blaster to send the signal to HA.
Looking at page 3 if looks like its possible to cut RJ2 and RJ3 that will isolate the tank circuit from from the microcontroller and power.
Then it would just be a case of providing 5V DC (after messing with it, I don’t want to plug it back into the wall) the raw signal will come from the OP amp pin 1 (or just tap off of RJ2).
All that said in my googling I have also found the X10 CM19A module - which is a bi-directional RF to USB dongle assuming its more performant ** than the CM11A it may be easier to adapt / write a driver for that.
** - Specifically I am concerned about latency between receiving the signal and sending the data to the PC.
Closing the loop on this I did ebay a CM19A.
From a latency standpoint it is really good, since there is no X10 electrical protocol involved - just delivering a RF message to the PC via USB.
The Mochad driver exposes that as a socket connection, hence it’s only a few lines of code to connect to the Mochad socket and forward incoming messages to MQTT.
The problem is that the RF receiver circuit / Antenna is fairly poor - it will detect PIR sensors but the wall mount switches can only be detected at approx. 1.5 meter (not useful) the receiver circuit in the RR501 can pick up the same signal at approx. 10x the range.
TBH it looks like the “antenna” wire is incorrect, since its only around 17 cm which would be roughly correct for a 433 MHz system, but at 310 Mhz it should be closer to 24 cm - I might try a quick fix for that, otherwise I am looking for a full schematic for the CM19A in order to replace the whole RF circuit - possibly with the one out of the RR501.