Daikin Mini Split Controller

A local-network HVAC controller for Daikin BRP072A43 mini-split Wi-Fi adapters. No cloud, no account — just direct HTTP control over your local network.

Built with WinUI 3 for Windows and ported to Android via Uno Platform.

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Features

• Real-time control — Temperature, mode (Cool / Heat / Auto / Dry / Fan), fan speed, and swing direction
• Custom temperature dial — Draggable arc knob with live Fahrenheit/Celsius display
• Staged settings — Edit multiple values, then apply in one tap
• Auto-refresh — Polls device state every 30 seconds in the background
• Weekly scheduling — Create up to 3 named schedules with 6 events per day
• Diagnostics — Live indoor/outdoor temperature, compressor frequency, error codes, raw API responses
• Dark theme — Designed for always-on display or casual use
• Connection resilience — Exponential backoff retry on GET requests, status badge indicators

Supported Hardware

Attribute	Value
Adapter	Daikin BRP072A43 (North American market)
Chipset	Murata / AMPAK (2.4 GHz Wi-Fi)
Protocol	HTTP GET on port 80 — unauthenticated
Discovery	Configurable IP address (default stored in settings)

Note: This adapter uses a legacy local REST API. The energy usage endpoints (get_week_power, get_year_power) are intentionally excluded — they crash the BRP072A43's single-threaded web server and require a breaker reset.

Architecture

MVVM + Dependency Injection
├── Models/          Immutable DTOs (DaikinState record), enums, converters
├── Services/        HTTP API client, settings persistence
├── ViewModels/      CommunityToolkit.Mvvm ObservableObjects
├── Views/           XAML pages (Controls, Schedule, Diagnostics)
└── Controls/        Custom TemperatureDial (canvas-drawn arc + knob)

Data Flow

┌───────────┐    ┌──────────────┐    ┌─────────────┐    ┌─────────────┐
│   XAML    │◄──►│  ViewModel   │◄──►│  API Service │───►│ Daikin Unit │
│  Views    │    │ (Observable) │    │   (HTTP)     │    │ (port 80)   │
└───────────┘    └──────────────┘    └─────────────┘    └─────────────┘

• MainViewModel (singleton) — owns the refresh timer, connection state, and cached DaikinState
• ControlsViewModel (singleton) — staged settings with dirty tracking
• DiagnosticsViewModel (transient) — reads cached state, zero network calls on navigation
• Tab switching is instant — no round-trips

Projects

Project	Target	Framework	Description
DaikinManagerV2	Windows	WinUI 3 / .NET 8	Primary desktop app
DaikinAndroid	Android + Windows	Uno Platform 6.5 / .NET 10	Mobile port
DaikinWinUI	Windows	WinUI 3 / .NET 8	Original prototype (archived)

Building

Windows (DaikinManagerV2)

cd DaikinManagerV2
dotnet build /p:Platform=x64
dotnet run /p:Platform=x64

Requirements: .NET 8 SDK, Windows 10 19041+, Windows App SDK 1.4

Android (DaikinAndroid)

cd DaikinAndroid/DaikinAndroid

# Set environment
$env:JAVA_HOME = "C:\Program Files\Microsoft\jdk-21.0.10.7-hotspot"
$env:ANDROID_HOME = "D:\Android\Sdk"

# Build APK
dotnet build -f net10.0-android -p:EmbedAssembliesIntoApk=true

# Install on device/emulator
adb install -r bin/Debug/net10.0-android/com.companyname.daikinandroid-Signed.apk

Requirements: .NET 10 SDK, JDK 21, Android SDK (API 35+, build-tools 35)

Configuration

The device IP address is stored via ISettingsService. Default: 192.168.183.26.

To change it, update the IP in Services/SettingsService.cs or through the app's settings.

API Reference

The BRP072A43 exposes a local HTTP API on port 80. All requests are GET, even writes.

Endpoint	Purpose
/aircon/get_control_info	Current power, mode, temperature, fan, swing
/aircon/set_control_info	Apply settings (requires all params)
/aircon/get_sensor_info	Indoor/outdoor temp, compressor Hz, error codes
/common/basic_info	MAC address, firmware version
/aircon/get_scdltimer	Read weekly schedule data
/aircon/set_scdltimer	Write weekly schedule (atomic, all 7 days)

Key Behaviors

• Hysteresis compensation: The unit applies a 1°C internal offset. The app adds/subtracts 1°C transparently so the displayed temperature matches what you'd expect.
• Compressor guard: Rapid OFF→ON toggling causes a 3-minute safety delay before the compressor restarts.
• Poll rate: The adapter is single-threaded — polling faster than every 5–10 seconds risks timeouts.

Acknowledgments

This project relies on the community-documented Daikin BRP072A43 local API, reverse-engineered and shared by contributors across the home automation community. Key references:

• ael-code/daikin-control — Comprehensive Daikin Wi-Fi API documentation and Python client
• Apollon77/daikin-controller-cloud — Daikin cloud and local API research
• Home Assistant Daikin integration — Community-maintained integration with extensive endpoint documentation

License

Private project — not licensed for redistribution.