Control your EuroAir/DomoAir ventilation system via ESP32.

Inspired by Raomin and his ESPAltherma, I built this solution for home ventilation systems from the manufacturer Swentibold. This includes the brands EuroAir and DomoAir (Austria). ESPLyfterl works with all models that can be controlled via a 3 or 4 position switch (modes: low, medium, high, off).

Features

• No need for extra hardware, just ESP32, two relays and some wires
• Control via MQTT and therefore all common home automation systems
• Supports update OverTheAir

Prerequisites

Hardware

• A Swentibold compatible home ventilation system
• An ESP32, my recommendation is the M5StickC Plus
• A 2 channel relay or 2 1 channel relays (low or high triggered)
• A 4 pin Grove interface to JST (for M5StickC) or any other 4 pin connection to 2 relays
• A 5V power supply for ESP32 (USB-C for M5StickC)

Software

• PlatformIO

Getting started

Step 1: Firmware

• Download the repository.
• Copy src/setup.tpl.h to src/setup.h and edit as follows:
  • Enter WiFi and MQTT settings.
  • Select the GPIO pins to control the relays. For M5StickC and M5StickC Plus the pins of the Grove interface are predefined (32 and 33) where 32 is to control relay 1 and 33 to control relay 2.
  • Uncomment whether your relays are low or high triggered.
• Ready, connect the ESP32 to your computer and run the following command in your console (where <your environment> is e.g. m5stickcplus).

  pio run --environment <your environment> --target upload

Step 2: Connection

• Turn OFF your home ventilation system at the circuit breaker.

• Find the appropriate connection on the board: SK6

  

• Connect your relays (normally open) as follows (usually you have to bridge GND):

  • The GND to GND of your relays.

  • 2 to the first relay controlled by PIN_LEVEL_2 (32 for M5StickC).

  • 3 to the second relay controlled by PIN_LEVEL_3 (33 for M5StickC).

  • Table and picture:

    SK6	Relay	Picture
    GND	GND	Green/Yellow
    2	Relay 1	Brown
    3	Relay 2	White

    

Step 3: Integration

Almost there! To control the ESP32 via MQTT use the home automation of your choice.

MQTT Topics

State Topic

esplyfterl/level/state

Command Topic

esplyfterl/level/set

openHAB Integration

I am using openHAB, so here's an example Thing configuration.

UID: mqtt:topic:XXXXXXXXXX:esplyfterl
label: ESPLyfterl
thingTypeUID: mqtt:topic
configuration: {}
bridgeUID: mqtt:broker:XXXXXXXXXX
channels:
  - id: esplyfterl_level
    channelTypeUID: mqtt:number
    label: ESPLyfterl Level
    configuration:
      commandTopic: esplyfterl/level/set
      stateTopic: esplyfterl/level/state
      min: 1
      max: 3

When using sitemaps in openHAB, here's a config.

Setpoint icon="fan" label="Ventilation Level" item=esplyfterl_level minValue=1 maxValue=3 step=1

Contributions

I am always happy to receive criticism, suggestions for improvement and participation. Feel free to send me bug reports or pull requests.

You can also buy me a beer via PayPal. Thanks! :-)

License

ESPLyfterl is licensed under MIT License.