A REST API server and MQTT client which provides control over IVT heatpumps, which uses a Rego6xx controller. Its the successor project of Rego6xxSrv. Homeassistant MQTT automatic device discovery is supported as well.

• Motivation
• Hardware
• Deployment
• Software
  • Installation
  • Build
  • Flash to target and monitor
  • Usage
• Sensors
• Binary Sensors
• Text Sensors
• Buttons
• Numbers
• API Endpoints and MQTT Topics
• SW-Architecture
• Details
  • Command IDs
  • System Register Addresses
    • Settings
    • Control Data
    • Device Values
    • Temperature Sensor Values
    • Front Panel LED and Button Addresses
• Used Libraries
• Issues, Ideas And Bugs
• License
• Contribution

Unfortunately my Junkers heatpump (original build by IVT) has no smart interface out of the box. Therefore the service interface of the build-in rego6xx controller shall be used to read sensor data or to modify temperature threshold and etc.

The first adapter I created was the Rego6xxSrv based on a ATmega644P, which is still up and running. But meanwhile the ATmega644P board I used is obsolete since 2024-01-01 and regarding my ideas the resources are very limited. Therefore the decision was made to create a secon adapter with less resource constraints and easier integration into a home automation.

The protocol for the Rego6xx controller was original derived from http://rago600.sourceforge.net/.

The Olimex ESP32-POE-ISO board with the RS-232 level shifter Olimex MOD-RS232 is used.

ESPHome is used as the base of the software. The IVT reg6xx controller is implemented like a custom component.

1. Install Python.

2. Setup virtual environment.

   python -m venv .venv

3. Activate virtual environment.

   • Windows CMD: .venv\Scripts\activate.bat
   • Windows PowerShell: .venv\Scripts\activate.ps1
   • Linux: .venv/Scripts/activate

4. Install packages.

   pip install -r requirements.txt

5. Create a secrets.yaml in the project root folder. Replace my_user and my_password according to the MQTT broker credentials.

   mqtt_broker: my_broker_url
   mqtt_user: my_user
   mqtt_password: my_password

esphome compile IVTRego6xxCtrl.yaml

esphome run IVTRego6xxCtrl.yaml

If you have further ideas or you found some bugs, great! Create a issue or if you are able and willing to fix it by yourself, clone the repository and create a pull request.

The whole source code is published under the MIT license. Consider the different licenses of the used third party libraries too!

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, shall be licensed as above, without any additional terms or conditions.