I would like some advice, for make a ducted AC zoning controller!

I have seen some projects, using esp + relay, to control synchronous motors, but only on and off.

I want to make a controller that can %open. and the relay plug is RJ12.

I’d love to get some tutorials and hardware advice! I’m not sure what hardware is needed, and how to control a synchronous motor.


Hey I think a few pics of what you’ve got or links to something similar might help people better understand what you’re facing.

thanks for your suggestion.

PICTURE1 This is the current damper motor controller. The part marked in red is connected to 6 damper motors. They are RJ12 plugs.

PICTURE2 It is damper motor RJ12 24V

PICTURE3 I want to connect the controller to wifi, but I don’t know how to do it now, can I do it with a PoE switch + ESP32?

Hope someone can teach me, or recommend some completed projects

Thanks, that’s a lot clearer. I’m not very experienced with this kind of project (so may be wrong with my advice), but here are my initial thoughts.

I think you need to sniff how the controller is controlling the motors.

You could cut a spare RJ45 cord, and start with a multimeter and check voltages on the wires. If you get some RJ45 breakouts this would be easier.

I’m not sure how safe tinkering with live 24v is. I’ve only fiddled with 5v.

My hunches would be:

  1. It’s just acting as relay and turning power on/off or
  2. If it’s got some electronics on the damper it might be using UART.

If it’s looking like the latter you could start investigating a similar approach to my project below.

You could always try posting/linking to this over on the ESPHome Discord. I had amazing help from ssieb over there for a vaguely similar project.

I suspect you’re going to have to do a fair bit of research and testing for this.

Here’s a very vaguely similar project I’m working on that may be of some use. It’s similar in the sense that there is basically a controller which is controlling two motors.

You do know that Ethernet and WiFi are not the same? It would make no sense to run Ethernet to the device just to provide power so that you can use WiFi.

You didn’t provide any specs or link to the valve, but most of them are 24VAC. You apply 24VAC to the valve to close it, remove power and it opens.

You have to get 24V to the damper, so why not use a 24VAC to 5VDC buck converter and a Wemos D1 mini at each valve? (ESP32 is way overkill for this). You can add a relay board to the Wemos to switch the power to the valve.

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Hi wondering how did your journey go, I’m about to embark on a similar project, keen to hear if there is anything that you could share

If this is on a central AC system, take care that you don’t close all of the dampers at the same time. The back-pressure could damage the fan unit, and if you close all dampers on a central heating system, you will likely damage the heat exchanger. (A very expensive repair).

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Thank you Stephen, that’s good to now, probably that’s something a smart system can avoid