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roscoe81 / Aircon-Controller

Raspberry Pi controller that provides the ability to control a Mitsubishi ducted air conditioner via its serial communications link so that it can be automated with the provision of temperature sensors in each room and monitoring/control of a two-zone airflow damper.
MIT License
15 stars 3 forks source link
air-conditioner air-conditioning aircon airconditioners airconditioning damper home-automation iot mitsubishi mqtt python raspberry-pi serial-communication smart-home thermostat

readme

Aircon-Controller

Controller for a Mitsubishi air conditioner (Model FDC508HES3) Provides mqtt control of the airconditioner using the serial communications link that runs between Mitsubishi's RCD-H-E remote control unit and the CNB port on the air conditioner's control board. Also provides the ability to control a damper so that airflow can be directed to the correct air conditioning zone. An inclinometer is provided for the damper in order to detect its position and control the air flow between zones with greater precision.

This project requires a separate mqtt-based controller that captures the actual temperatures of each room, compares those temperatures to desired temperature levels and controls the air conditioner and damper to align the desired and actual temperatures. I've implemented such a controller as part of a more comprehensive Home Automation System.

Hardware Schematics

Aircon Controller Schematic

Damper Position Sensor Schematic

Damper Control Board Schematic

Hardware Photographs

Aircon Controller

Damper Position Sensor

Note that the damper controller switches high voltages and it should only be constructed and deployed by a licensed electrician.

Air Conditioner Communications Protocol

I've included a document that shows what I found when reverse engineering the protocol between the Mitsubishi RCD-H-E remote control unit and the CNB port on the air conditioner's main unit. There are still gaps in some areas of that protocol but all essential functions are covered.

Communications Protocol

Version 5.1 Gen

Version 5.1 Gen adds the ability to control dampers for each room and to control fan speed. Hardware changes were necessary to control each room damper.

Aircon Room Damper Schematic

Aircon Controller with Room Dampers.

License

This project is licensed under the MIT License - see the LICENSE.md file for details

Acknowledgements

I'd like to acknowledge the work done by Hadley Rich who did similar work on a Mitsubishi air conditioner that provided me with the inspiration to undertake this task.