Connect ESP32 as Vent-Axia MVHR remote unit
This is just in Proof-of-concept stage!!!
At this time, this module can read Vent-Axia cable remote messages and responses and logs them to the Serial interface
The circuit uses MAX3232 circuit to convert between MCU voltage levels (3V3) and RS232 (+/- 10V).
The ESP-in-the-middle processes packets and sends them to designated receiver.
This configuration allows logging and also modifying data.
The J4 connector is designed to connect a bunch of DS18B20 or DS18S20 sensors to measure temperatures at each input/output of the MVHR. (This will be implemented later on this mdule as this is for me currently provided by another ESP). But this is a good feature to see the Energetic benefits of having an MVHR, or to calculate thermal efficiency :)
Just for a sneak-peek - this is how the temperature infos about MVHR look for me in Homeassistant:
- Read and process keyboard status
- Read and process display messages from MVHR
- Add independent 5VDC power source - the integrated PSU cannot power ESP32 due to high current draw
- Test keyboard command insertion
- Test display hijacking -> sending custom messages
- Add support for DS18x20 sensors for temperature measurement
- Add OTG support
- Add MQTT Interface
- Add Humidity measurement
- Maybe? Add Web Interface
- Maybe? Add CO (Carbon-Monoxide) level measurement
- Add schematics
- Add support for OneWire sensors
- Add Humidity measurement sensors
- Maybe? Add relay output to control high flow request
- Maybe? Add analog-out (0-10V) to control flow
- Design the PCB