Existing hardware integration flowunit


In my house we have 6 electronically operated airflow units in our windows. Usually these things are manually operated, but we have this fancy and never working electronic system :wink:
The company that made the things (Alusta) is bankrupt.

The airflow units itself are actually very good. They always work and we can operate then using a IR remote control. The system is actually more fancy then that, because these units are usually automatically operated based on humidity and CO2 level. (that part is the non-working part :wink: )

I have managed to operate the units using a esp32, esphome and a IR transmitter. I can then close and open the airflow unit. It however sometimes misses the IR signal and fails to open/close.

I would like to embed a ESP8266 or ESP32 in the unit itself and operate by GPIO directly. I can get 5v from the mainboard of the unit. (The programming header for the ATmega32L (H2) has GND on pin3 and pin1 has +5v DC)

The unit consists of a PCB with a ATmega32L chip. There is a airflow sensor on the back to measure the wind outside blowing into the unit. There is 2 blue connectors, 1 leading to the motor (12v DC), 1 leading to the end-stop sensor.

I have been able to find out the following:

  1. The unitโ€™s power supply is 12-24V AC fed through the RJ45 connector (pin 3 and 8)
  2. The units operating modes (by remote) are open-middle-close-auto
  3. The auto mode closes and opens based on the wind being blow in the back of the unit and based on CO2/humidity level measured from a CO2/Humidity sensor connected to the RJ12 connector.
  4. The RJ12 (sensor) connector has:
    Pin 1 - 12/24v AC
    Pin 2 - GND
    Pin 3 - nc
    Pin 4 - nc
    Pin 5 - Analog signal from sensor
    Pin 6 - 12/24v AC

I think the best approach would be to simulate the analog signal coming from the analog sensor. Another approach could be to connect to the IR receiver and emulate the IR signal? I do not have much electronics knowledge. What would be the best way to do this and how??





Interesting project.

Please remember that espโ€™s are 3v3 devices. Many can be powered 5v, espcially if they have a usb port. However logic levels are stil 3v3.

Thanks, I am aware of that. The esp32 d1 mini I plan to use has a 5v VIN.

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