Wirsbo 433 transmitters for floor heating

I have a wirsbo floor heating system with transmitters tja commuicates with 433mhz. The transmitters Are marked «Cozy Radio» wirsbo artnr 80440 and f.ex. ID0413 - 433,7 MHz.

The receivers look like this:

The transmitters are nor produced anymore, and I was hoping to control the system via Homey rather than buying new controllers. But I cannot find a way to add or control the 433 thermostats in Homey. Grateful for any hints or guidance :wink:

I know this topic is rater old, but I stumbled on it - and since no one else posted a reply I might as well do it…

We have this exact same system in our house, and for (almost) the same reasons as you, I took a stab at it last year.
It turns out that it’s quite simple actually!
It’s a one way system, so you won’t be able to control it unless you create your own transmitter - either from salvaged parts, or program your own :slight_smile:

In the latter case, you might as well buy a WIFI operated 24VAC switch system to open/close the actuators.

Each wireless thermostat wakes up once ever 10-15 minutes, measures the temperature, integrates it with the last x measurements - and decides whether or not heat is needed.
In either case, a small packet (~35 bits @ 2500 baud) is sent to the receiver using basic FSK (I think).
The packet is sent 3-4 times with a delay of 10-11 seconds between each, YMMV.
The packet contains the unique ID of the thermostat, whether or not heating is requested, and the current setting of the night time temperature switch - that’s it!

Furthermore the packet is prepended with a preamble to ‘wake-up’ the receiver, and contains start/stop bits and basic parity checks.

Also worth mentioning is that the RF receiver circuit in the controllers actually contains a signal-strength output, but this isn’t used by the microcontroller at all.

Like yours - our system contains an extender unit, but when this malfunctioned I salvaged the RF receiver and programmed an ESP32 based WIFI/MQTT gateway from the parts.

Now I can at least monitor when each thermostat calls for heat in Home Assistant :smiley:

Note that the above info might not be 100% accurate, so use it as is and make your own observations :wink:

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Tnx for sharing. The answer was way above my level, but Tnx anyway :wink: