HomeKit Irrigation System

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Overview

Standalone HomeKit-enabled irrigation system built using HAP-NodeJS.

Provides:

• Multi-zone irrigation control
• Water tank level monitoring (ultrasonic)
• Flow-based leak detection
• EveHome history support
• Built-in Web UI (HomeKitUI)
• No Homebridge required

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Web UI (HomeKitUI)

This project includes a built-in web interface powered by HomeKitUI.

Features

• Dashboard with live water tank levels
• Irrigation zone configuration
• Tank configuration
• System options
• Live log streaming
• HomeKit pairing management
• Configuration backup/restore
• Optional bearer-token authentication

Access

http://<device-ip>:8582

Port is configurable via:

options.webUIPort

Authentication

HomeKitUI supports optional bearer-token authentication.

When configured:

• API access requires a bearer token
• Browser UI stores the token locally after first authentication
• Live log streaming remains supported via secure SSE token fallback

Example:

"webUIBearerToken": "your-secret-token"

To disable authentication:

"webUIBearerToken": ""

Dashboard

Displays:

• Water tank levels (percentage + litres)
• Tank capacity
• Last updated readings
• Zone runtime state
• Water usage information

Tank data is updated automatically from sensor events.

Notes

• Fully self-contained UI (no external frontend)
• Config changes may require restart
• Log sources (priority):
  1. journald (systemd)
  2. log file (if configured)
  3. console (fallback)

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Parts

Built with readily available off-the-shelf components, housed in a sealed ABS enclosure.

As the system is installed externally, mains wiring (240v → 24v transformer) is isolated in a separate enclosure.

• Raspberry Pi Zero W
• 24v AC transformer (Hunter irrigation)
• LM2596HV AC/DC step-down converter (5v output)
• JSN-SR04T waterproof ultrasonic sensor
• 8-channel solid-state relay board (high-level trigger)
• Water flow sensor (pulse output)
• Waterproof push-on/push-off LED switch
• Mains power cable
• Irrigation wiring

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Water Tank Configuration

Defined in IrrigationSystem_config.json under tanks.

Example:

"tanks": [
  {
    "name": "Rainwater Tank",
    "enabled": true,
    "capacity": 5000,
    "sensorTrigPin": 20,
    "sensorEchoPin": 21,
    "sensorHeight": 1970,
    "minimumLevel": 200
  }
]

Name	Description
name	Tank name
enabled	Enable/disable tank
capacity	Tank capacity (litres)
minimumLevel	Minimum measurable level (mm)
sensorEchoPin	GPIO echo pin
sensorTrigPin	GPIO trigger pin
sensorHeight	Sensor height above tank base (mm)
uuid	Auto-generated (DO NOT CHANGE)

Tank Behaviour

• Ultrasonic sensor measures water distance
• Readings are smoothed internally
• Percentage is calculated from:
  • sensor height
  • minimum usable level
• Dashboard displays:
  • % full
  • litres remaining
  • last updated time

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Irrigation Zone Configuration

Defined in zones.

"zones": [
  {
    "name": "Back Lawn",
    "enabled": true,
    "runtime": 300,
    "relayPin": 14
  }
]

Name	Description
name	Zone name
enabled	Enable/disable zone
relayPin	GPIO relay control pin or array of pins
runtime	Default runtime (seconds)
uuid	Auto-generated

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Configuration Options

Defined under options.

Name	Description	Default
debug	Enable debug logging	false
elevation	Height above sea level	0
eveHistory	Enable EveHome history	true
flowRate	Flow sensor rate (L/min @1Hz)	—
latitude	Location latitude	0
longitude	Location longitude	0
leakSensor	Enable leak sensor	false
powerSwitch	Virtual power switch	false
maxRuntime	Maximum zone runtime (seconds)	7200
sensorFlowPin	Flow sensor GPIO	—
usonicBinary	Path to ultrasonic measurement binary	./usonic_measure
waterLeakAlert	Trigger HomeKit alert	false
webUIPort	HomeKitUI port	8581
webUIBearerToken	Optional HomeKitUI bearer token	""

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Ultrasonic Water Level Measurement

Includes usonic_measure.c for accurate ultrasonic sensor timing.

Requires:

sudo apt install wiringPi

Compile:

gcc -o dist/usonic_measure src/usonic_measure.c -l wiringPi

Sensor used:

• JSN-SR04T
• Minimum distance: ~200mm
• Maximum distance: ~4500mm

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HomeKit Integration

Exposes:

• IrrigationSystem service
• Valve services (zones)

Optional services:

• Leak sensor
• Power switch

Supports:

• Siri control
• EveHome advanced features
• History logging

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Disclaimer

This is a personal hobby project provided "as-is", with no warranty whatsoever, express or implied, including but not limited to warranties of merchantability or fitness for a particular purpose.

Building and running this project is done entirely at your own risk.

⚠️ This project involves mains power wiring. It is strongly recommended that you engage a licensed electrician where required and ensure all installations comply with local regulations.

I am not affiliated with any companies such as Apple or other related entities. The author of this project shall not be held liable for any damages or issues arising from its use.

If you find this project useful, sponsorship to support ongoing development is always appreciated.