HomeKit Generator Grid Controller

A HomeKit-enabled automatic generator controller for ESP32 that monitors grid power and manages generator operations. Built with HomeSpan.

Features

• HomeKit integration for remote monitoring and control
• Three operating modes:
  • Auto Mode: Automatically starts generator on grid failure
  • Manual Mode: Manual generator control
  • Off Mode: Completely disables generator
• Real-time status updates in Apple Home app
• Grid power monitoring with configurable delays
• Intelligent generator start sequence with choke control
• Transfer switch management
• Multiple start attempts with configurable retry logic
• Safe mode switching with proper shutdown sequences
• Serial monitor status reporting

Requirements

• ESP32 development board
• HomeSpan library
• Arduino IDE
• Apple HomeKit compatible device
• Generator with:
  • Electric start
  • Choke control
  • Transfer switch
  • Running status sensor

Hardware Setup

Required connections:

• Grid Monitor Pin (32): Connect to grid power sensor (LOW = power present)
• Generator Monitor Pin (33): Connect to generator running sensor (HIGH = running)
• Generator Power Pin (25): Controls main generator power (LOW = ON)
• Generator Choke Pin (26): Controls generator choke (LOW = ON)
• Generator Starter Pin (27): Controls starter motor (LOW = ON)
• Transfer Switch Pin (14): Controls transfer switch (LOW = ON)

Installation

1. Install HomeSpan library in Arduino IDE
2. Clone or download this repository
3. Edit config.h with your settings:
   • WiFi credentials
   • HomeKit pairing code
   • Timing adjustments if needed
   • GPIO pin configuration
4. Upload to your ESP32

Required Configuration (config.h)

Operation

Auto Mode

1. Monitors grid power status
2. On grid failure:
   • Confirms outage (10s delay)
   • Starts generator
   • Manages choke
   • Engages transfer switch
3. On grid restoration:
   • Confirms stable power (10s delay)
   • Disables transfer switch
   • Stops generator

Manual Mode

1. Starts generator on demand
2. Manages choke sequence
3. Controls transfer switch
4. Provides safe shutdown

Off Mode

1. Safely shuts down generator
2. Disables transfer switch
3. Prevents automatic operation

HomeKit Integration

• Appears as three switches in Apple Home:
  • Auto Mode Switch
  • Manual Mode Switch
  • Off Mode Switch
• Only one mode active at a time
• Real-time status updates
• Remote control capability

Safety Features

• Grid power confirmation delays
• Multiple start attempt protection (3 attempts max)
• Safe mode switching
• Proper shutdown sequences
• Transfer switch safety delays
• Choke control management
• Immediate stop on mode change

Serial Monitor

Commands:

• 's': Display current status Output includes:
• Mode changes
• Grid status
• Generator state
• Start/stop sequences
• Error conditions

Troubleshooting

1. Generator won't start

   • Check pin connections
   • Verify power connections
   • Check serial output for errors
   • Ensure proper timing settings

2. HomeKit not connecting

   • Verify WiFi credentials
   • Check HomeKit code
   • Reset ESP32
   • Check network connectivity

3. Mode changes not updating

   • Check WiFi connection
   • Monitor serial output
   • Verify HomeKit connectivity

License

MIT License

Contributing

1. Fork the repository
2. Create feature branch
3. Submit pull request

Credits

• HomeSpan library: HomeSpan on GitHub
• Developed by: Manuel Duarte
• Version: 1.0.0