MHI Smart M-Air Plugin for Scrypted

A Scrypted plugin for controlling Mitsubishi Heavy Industries (MHI) air conditioners equipped with the WF-RAC WiFi module (Smart M-Air).

Features

• Multiple AC Unit Support - Control multiple MHI air conditioners from a single plugin
• Auto-Discovery - Scan your network to find MHI devices automatically
• Auto-Registration - Automatically registers "Scrypted" as an operator with the AC unit
• Thermostat Control - Off, Cool, Heat, Auto, Fan Only, Dry modes
• Temperature Control - Set target temperature (18-30°C in 0.5° increments)
• Fan Speed Control - Auto, Lowest, Low, High, Highest
• Indoor Temperature - Real-time indoor temperature readings
• Outdoor Temperature - Separate sensor for outdoor condenser temperature

Supported Devices

This plugin works with MHI air conditioners that have the WF-RAC WiFi module, typically configured via the Smart M-Air mobile app.

Both firmware generations are supported, detected automatically per device:

• Legacy firmware - plain HTTP on port 51443 (/beaver/command)
• WF-RAC-HTTPS firmware (wireless v025 / MCU v200 and newer) - TLS on port 51443 (/beaver/command/<command>), using the unit's self-signed certificate

Installation

1. In Scrypted, go to Plugins > Install Plugin
2. Search for "MHI Smart M-Air" or install from NPM: @scrypted/mhi-smartmair

Setup

1. Open the plugin settings
2. In Scan Network, enter AUTO to automatically detect your network subnets
   • Or enter a specific subnet manually (e.g., 192.168.1 or 10.2.2)
3. The plugin will automatically:
   • Scan for MHI devices on port 51443
   • Register "Scrypted" as an operator with each device
   • Add discovered devices to Scrypted
   • Update IP addresses if devices have moved

Your AC units will appear as thermostats, each with a separate outdoor temperature sensor.

Device Interfaces

Each AC unit exposes:

| Interface | Description | |-----------|-------------| | TemperatureSetting | Thermostat mode and target temperature | | Thermometer | Current indoor temperature | | Fan | Fan speed control | | OnOff | Power on/off | | Refresh | Manual status refresh |

Each AC unit also creates a child Outdoor Temperature Sensor.

Settings

Plugin Settings

| Setting | Description | |---------|-------------| | Polling Interval | How often to poll device status (5-60 seconds, default: 10) |

Discovery Settings

| Setting | Description | |---------|-------------| | Scan Network | Enter AUTO to auto-detect subnets, or enter manually (e.g., "192.168.1") | | Last Discovery Result | Shows results of the last scan | | Add Device by IP | Add a specific device by IP address |

Device Settings

| Setting | Description | |---------|-------------| | Name | Display name for the AC unit | | IP Address | Network address of the AC unit | | MAC Address | Device identifier (read-only) |

Thermostat Modes

| Mode | Description | |------|-------------| | Off | Power off | | Cool | Cooling mode | | Heat | Heating mode | | Auto | Automatic mode | | Fan Only | Fan only (no heating/cooling) | | Dry | Dehumidifier mode |

Apple HomeKit only supports Off / Heat / Cool / Auto, so Fan Only and Dry are not selectable from the Home app (they show as Auto there). They are available from the Scrypted UI and other integrations.

Fan Speeds

| Level | Description | |-------|-------------| | Auto | Automatic fan speed | | Lowest | 25% | | Low | 50% | | High | 75% | | Highest | 100% |

Troubleshooting

Device Not Found

• Ensure the AC unit is connected to your network
• Check that port 51443 is accessible
• Try probing the specific IP address

Commands Not Working

• The plugin auto-registers its operator ID - check the device console for errors
• Ensure your system clock is accurate (timestamps are required)

Notes

• Transport: Each unit's transport is auto-detected - HTTPS first (newer WF-RAC-HTTPS firmware, self-signed certificate), falling back to plain HTTP (legacy firmware). No configuration needed. The same status-buffer encoding is used for both.
• Temperature decoding: Indoor and outdoor temperatures use the manufacturer lookup tables. The local-API indoor reading can sit a few tenths of a degree off the Smart M-Air app.
• IP changes: Re-running a scan will automatically update device IP addresses if they have changed (e.g., after DHCP renewal).

Credits

Based on protocol work from:

• homebridge-mhi-wfrac by Job Doesburg
• Mitsubishi-WF-RAC-Integration for Home Assistant
• ioBroker.mhi-wfrac by hacki11

License

Apache-2.0