HomeKey-ESP32

Apple HomeKey functionality for the rest of us

Documentation

What is HomeKey-ESP32?

The project aims to be the easy DIY solution for using Apple's HomeKey feature without the need to purchase a compatible smart lock that you probably don't want. HomeKey-ESP32 brings Apple's secure NFC-based unlocking to an ESP32 module near you, enabling you to unlock doors and whatnot with a simple tap of your iPhone or Apple Watch.

No proprietary hardware required – just an ESP32 and one of the supported NFC modules

[!WARNING] The flash memory is not encrypted as this kinda started as a pet project of mine but a lot of people started using so unfortunately it's stuck like this because migration would be painful and i don't want to be telling people to reconfigure their device if they want to update.

If you care about this, i'm working on a new project implementing the new Aliro standard and flash will be encrypted first thing, however, honestly don't know when that will be public, you can join the Discord server if you want to know as soon as it is available.

Getting Started

[!TIP] A wiki documenting the project can be found at https://rednblkx.github.io/HomeKey-ESP32/

Prerequisites

• ESP32 Development Board
• NFC reader - one of:
  • PN532 (SPI)
  • PN7161 (SPI) - available in the dev release
  • ST25R3916 (I2C) - available in the dev release
• USB Cable (for flashing and power)
• Computer (Windows, Mac, or Linux)
• Basic Electronics Knowledge (not a problem if you're new to this, ask away!)

Ethernet

The following chips are supported for Ethernet:

• W5500
• DM9051
• KSZ8851
• LAN8720 / LAN8710
• TLK110
• RTL8201
• DP83848
• KSZ8041
• KSZ8081

[!IMPORTANT]

The following are only supported for ESP32-WROOM-32 boards as other variants lack the internal EMAC needed for the RMII interface:

• LAN8720 / LAN8710
• TLK110
• RTL8201
• DP83848
• KSZ8041
• KSZ8081

Installation Steps

1. Download Firmware

   • Visit GitHub Releases
   • Download the *.firmware.factory.bin file
   • This contains everything you need - no compilation required!

2. Connect Your Hardware

   • Wire your chosen NFC module to your ESP32 using the default pins
   • Refer to the detailed wiring guide for your specific setup

3. Flash the Firmware

   # Install esptool (one-time setup)
   pip install esptool
   
   # Flash the firmware (replace YOUR_PORT)
   esptool.py --port /dev/ttyUSB0 write_flash 0x0 firmware.factory.bin
   

   Prefer a GUI? Use the browser-based flasher - no command line needed!

4. Initial Setup

   • Connect to the device's WiFi AP (HomeSpan-Setup / homespan)
   • Access the web interface at http://192.168.4.1
   • Configure your WiFi credentials and HomeKit setup code
   • Pair with Apple Home using code: 466-37-726

5. Start Using HomeKey!

   • Hold your iPhone or Apple Watch near the NFC reader
   • Enjoy instant, secure access to your home! 🎉

Updating

Follow the update in the documentation at: https://rednblkx.github.io/HomeKey-ESP32/updates/

System Architecture

graph TD
    A[iPhone/Apple Watch] -->|RF| B[NFC Module]
    B -->|SPI| C[ESP32]
    C -->|MQTT| D[Home Assistant/Broker]
    C -->|HomeKit| E[Apple Home]
    C -->|HTTP| F[Web Interface]
    C -->|GPIO| G[Physical Lock]
    
    subgraph "HomeKey-ESP32 Core"
        C
        H[ConfigManager]
        I[LockManager]
        J[NfcManager]
        K[HomeKitLock]
        L[WebServerManager]
        M[MqttManager]
    end
    
    style A fill:#1f2937,stroke:#374151,color:#fff
    style C fill:#059669,stroke:#047857,color:#fff
    style B fill:#3b82f6,stroke:#2563eb,color:#fff

✨ Key Features

Apple HomeKey Integration

• Express Mode: Unlock without waking your device
• Power Reserve: Unlock even when the device needs to be charged
• Multi-Device Support: Works with iPhone and Apple Watch
• Fast Authentication: Sub-300ms unlock times

Smart Home Ready

• HomeKit Native: Full Apple Home ecosystem integration
• MQTT Support: Connect to Home Assistant, OpenHAB, and other platforms
• Home Assistant Discovery: Automatic device detection and configuration
• Custom States: Support for complex lock states (jamming, unlocking, etc.)

Modern Web Interface

• Svelte Frontend: Responsive, modern UI built with Svelte 5 + Tailwind CSS
• Real-time Updates: WebSocket-powered live status updates
• OTA Updates: Over-the-air firmware updates via web interface
• Configuration Management: Easy setup without recompiling

Developer Friendly

• Open Source: MIT licensed, community-driven development
• Modular Architecture: Clean separation of concerns
• Event System: Pub/sub architecture for extensibility
• Comprehensive Logging: Debug and monitor with detailed logs

Development

graph TD
  %% External Systems & Hardware
  subgraph "External World"
      A[iPhone / Apple Watch]
      B[Apple Home]
      C[Web Browser]
      D[MQTT Broker]
      E[Physical Lock, Buttons & LEDs]
  end

  %% Main Application on ESP32
  subgraph "HomeKey-ESP32 Core"
      
      subgraph "Interface Managers (I/O)"
          direction LR
          Nfc[NfcManager]
          HK[HomeKitLock]
          Web[WebServerManager]
          Mqtt[MqttManager]
          Hw[HardwareManager]
      end

      subgraph "Logic Core (State Machine)"
          Lock[LockManager]
      end

      subgraph "Data Services (Persistence)"
          direction LR
          Config[ConfigManager]
          Reader[ReaderDataManager]
          NVS[(NVS Storage)]
      end

      %% High-level Data and Control Flow
      DataServices[Data Services] -- "Provides Config & Reader Data" --> InterfaceManagers[Interface Managers]
      DataServices -- "Provides Config" --> LogicCore[Logic Core]
      Config -- "Reads/Writes" --> NVS
      Reader -- "Reads/Writes" --> NVS
      
      InterfaceManagers -- "State Change Requests (e.g., Unlock)" --> Lock
      Lock -- "Actions & State Updates" --> InterfaceManagers
  end
  
  %% Connections to the External World
  A -- NFC --> Nfc
  B -- HomeKit --> HK
  C -- HTTP/WebSocket --> Web
  D -- MQTT --> Mqtt
  E -- GPIO --> Hw
  
  Hw -- GPIO --> E
  HK -- HomeKit --> B
  Web -- HTTP/WebSocket --> C
  Mqtt -- MQTT --> D

  %% Styling for clarity
  style A fill:#1f2937,stroke:#374151,color:#fff
  style B fill:#1f2937,stroke:#374151,color:#fff
  style C fill:#1f2937,stroke:#374151,color:#fff
  style D fill:#1f2937,stroke:#374151,color:#fff
  style E fill:#1f2937,stroke:#374151,color:#fff

  style Nfc fill:#3b82f6,stroke:#2563eb,color:#fff
  style HK fill:#059669,stroke:#047857,color:#fff
  style Web fill:#f59e0b,stroke:#d97706,color:#fff
  style Mqtt fill:#ef4444,stroke:#dc2626,color:#fff
  style Hw fill:#8b5cf6,stroke:#7c3aed,color:#fff

  style Lock fill:#ec4899,stroke:#db2777,color:#fff
  
  style Config fill:#6b7280,stroke:#4b5563,color:#fff
  style Reader fill:#6b7280,stroke:#4b5563,color:#fff
  style NVS fill:#9ca3af,stroke:#6b7280,color:#fff

Project Structure

HomeKey-ESP32/
├── main/                    # Core ESP32 application
│   ├── main.cpp            # Application entry point
│   ├── ConfigManager.cpp    # Configuration management
│   ├── ReaderDataManager.cpp # Reader data management
│   ├── NfcManager.cpp      # NFC communication
│   ├── Pn532Reader.cpp     # PN532 backend (SPI)
│   ├── Pn7160Reader.cpp    # PN7160 backend
│   ├── St25r3916Reader.cpp # ST25R3916 backend (I2C)
│   ├── HomeKitLock.cpp     # HomeKit integration
│   ├── LockManager.cpp     # Lock state management
│   ├── MqttManager.cpp     # MQTT client
│   ├── WebServerManager.cpp # Web interface
│   ├── WebSocketLogSinker.cpp # WebSocket logging sinker
│   ├── HardwareManager.cpp # Hardware manager
│   └── HKServices.cpp # HomeKit services
├── data/                   # Web interface files
│   ├── src/               # Vue.js application
│   └── index.html         # Web UI entry point
├── components/            # External dependencies
│   ├── HK-HomeKit-Lib/   # HomeKey implementation
│   ├── HomeSpan/         # HomeKit framework
│   └── PN532/            # NFC driver
└── docs/                 # Documentation
    └── content/          # Hugo documentation

Core Components

Building from Source

# Install dependencies
git submodule update --init --recursive

# Install esp-idf v5.4 or newer -- CI builds against v5.5.4.
# Earlier versions do not compile: the pn7160 and pn532_hal components use
# esp_log_buffer.h and spi_bus_dma_memory_alloc, both introduced in v5.4.
# See https://docs.espressif.com/projects/esp-idf/en/latest/esp32/get-started/index.html#get-started

# Build firmware
idf.py build

# Flash to device
idf.py -p /dev/ttyUSB0 flash

# Monitor output
idf.py monitor

Contributing

Contributions are welcomed! Please see the Contributing Guidelines for details.

1. Fork the repository
2. Create a feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'feat: Add amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request against the main branch

Support the Project

HomeKey-ESP32 is openly developed and maintained by the community. Your support helps us continue improving the project.

• Star the repository to show your appreciation
• Report bugs to help improve stability
• Suggest features to guide development
• Share the project with your network
• Contribute documentation to help others

Credits

• @kormax: Reverse-engineered the HomeKey NFC protocol and published the foundational PoC implementation
• @kupa22: Researched the HAP (HomeKit Accessory Protocol) side of HomeKey
• HomeSpan: Excellent HomeKit framework that powers our integration
• ESP-IDF: Robust IoT development framework from Espressif

License & Legal

License

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

Disclaimer

Important: This project implements Apple HomeKey functionality through reverse engineering. While we strive for security and compatibility:

• Not affiliated in any shape or form nor condoned by Apple Inc.
• Use at your own risk for security-critical applications
• May lack elements from Apple's private specifications
• Subject to change as Apple updates their protocols

Trademarks

• Apple, iPhone, and Apple Watch are trademarks of Apple Inc.
• ESP32 is a trademark of Espressif Systems (Shanghai) Co., Ltd.
• Home Assistant is a trademark of Open Home Foundation