Setting up an RF bridge for a Könighaus LED ceiling heating

[Patrick4 (Patrick)]

I am starting with my first ESPHome project. I just bought a Könighaus LED ceiling heating and I would like to replace the remote control with an integration with Home Assistant. Since there is no IR LED on that remote, I can only suppose it is an RF one. I sent a mail to the manufacturer, just in case they would reply.

The features of the remote are:

• toggle the heating,
• decrease/increase the temperature,
• set a timer value from a list of options,
• toggle the light (which cycles through different modes).

I understand it is recommended to:

• buy a Sonoff RF Bridge and the gear listed in the following article (USB to serial adapter and wires);
• follow the instructions in How to flash the Sonoff RF BridgeR2 with ESPHome;
• head to Setting up RF Devices, probably covered already in the above guide.

Am I missing something? Thanks in advance.

[Karosm]

It’s anything between easy and impossible.
Instead of blindly buying some RF bridge, spend some time to find out what approach they use. Could be 433MHz or 2.4GHz…Or something else.
You can open remote controller or receiver to get some evidence if google search doesn’t give anything.

[Patrick4 (Patrick)]

Thanks for the suggestion! I opened the receiver. I don’t think I can open the remote without damaging it.

I think it seriously resembles a 433 MHz receiver like this one: Google Image Result for https://www.robozar.com/wp-content/uploads/2024/05/cha.jpg.

Could it still be something else?

[IOT7712]

Is there a FCC id sticker somewhere that could lead to clues?

The clue is the antenna. Looks like one for 433Mhz.

433Mhz - you still have to decode the protocols used. A matching dedicated encoder/decoder IC pair is often used. You may even encounter rolling code protocols.

Have a look at what that 4 pin transmitter/receiver board is connected to nearby. A closeup photo of the circuit board (including IC part numbers clearly identifiable) would be of great assistance.

Can you check the part number of the IC on that 4 pin daughter board and advise. Cannot see it in your photo.

Have a look at what rabbit hole you may wander down looking to reverse engineer raw transmitted data here:

How to send an RF code I already know with Broadlink

I’m trying to send 433MHz RF codes through my Broadlink RM4 Pro. I already know the proper codes. I need to send 0x49C744 (24 bits). But all I am getting is either errors or what appears to be a success, except nothing works. I have verified the code works through other means. I’ve read about using b64:. But that isn’t working. I saw on this page, that the code must include some flag about whether it is IR or RF, but nothing explains how to include that when doing the base64 encoding!?! H…

Hint: easier to check the data sheet on the ICs on the board. Take the photos. Post them here.

[Karosm]

@Patrick4

Could it still be something else?

No.
It’s 433MHz ASK receiver, Qiachip RX500.
You can’t find approach easier than this …

[Patrick4 (Patrick)]

In case it is relevant for other purposes than identifying the daughter board, here are the requested photos. Consider a vertical flip between the pictures.

Thank you all for your time!

[Karosm]

You can go with the original plan with rf-bridge.
Or get cheap 433 modules and esp dev board.

Or if you like soldering and tinkering plus saving few dollars, remove the receiver from motherboard and connect it to esp dev board. Record the signals you need and solder esp in the place of that receiver.

[Patrick4 (Patrick)]

@Karosm

get cheap 433 modules and esp dev board

Interesting! I don’t find those modules listed in the documentation. Do I just need to find ESP32 compatibility? If you have known working examples, I welcome them.

[Karosm]

433MHz superheterodyne receiver and transmitter combo. Like this:

Receiver to copy the signals from your original remote and transmitter to send them from esphome to your heater.

Setting up RMT Devices