homebridge-web-sprinklers

Description

This homebridge plugin exposes a web-based sprinkler system to Apple's HomeKit. Using HTTP requests, the plugin allows you to turn on/off individual sprinkler zones. With the use of the OpenWeatherMap API, the plugin can also provide water scheduling.

Find script samples for the sprinkler controller in the examples folder.

Installation

1. Install homebridge
2. Install this plugin: npm install -g homebridge-web-sprinklers
3. Sign up (for free) to the OpenWeatherMap API and retrieve your API key (if you want scheduling)
4. Update your config.json file

Configuration

Accessory with scheduling

"accessories": [
     {
       "accessory": "WebSprinklers",
       "name": "Sprinklers",
       "apiroute": "http://myurl.com",
       "latitude": 0000000000,
       "longitude": 0000000000,
       "key": "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx",
       "zones": 6,
       "restrictedMonths": [0, 1, 2, 10, 11],
       "zonePercentages": [100, 75, 100, 100, 50, 100]
     }
]

Accessory without scheduling

"accessories": [
     {
       "accessory": "WebSprinklers",
       "name": "Sprinklers",
       "apiroute": "http://myurl.com",
       "disableScheduling": true
     }
]

Core

Key	Description	Default
accessory	Must be WebSprinklers	N/A
name	Name to appear in the Home app	N/A
apiroute	Root URL of your device	N/A
latitude	Your decimal latitude	N/A
longitude	Your decimal longitude	N/A
key	Your OpenWeatherMap API key	N/A
zones	Number of sprinkler zones	6

Optional fields

Key	Description	Default
disableScheduling	Whether to disable water scheduling	false
sunriseOffset	Minutes before sunset to finish watering by	0
defaultDuration	Default total watering time per zone (minutes)	20
cycles	Number of cycles per zone (watering is spread between cycles)	2
restrictedDays	Days of the week when watering should not take place (Sunday is 0, Monday is 1, and so on)	N/A
restrictedMonths	Months of the year when watering should not take place (January is 0, February is 1, and so on)	N/A
zonePercentages	Percentage of calculated zone watering time that a specific zone will receive (do not exceed 100%)	100
disableAdaptiveWatering	Whether to disable adaptive watering and use defaultDuration instead	false
maxDuration	The highest number of minutes that adaptiveWatering can set	30
lowThreshold	Forecasted low temperature (°C) below which watering will not take place	10
highThreshold	Forecasted high temperature (°C) below which watering will not take place	20
rainThreshold	Forecasted rainfall (mm) above which watering will not take place	2.3

Additional options

Key	Description	Default
pollInterval	Time (in seconds) between device polls	300
listener	Whether to start a listener to get real-time changes from the device	false
timeout	Time (in milliseconds) until the accessory will be marked as Not Responding if it is unreachable	3000
port	Port for your HTTP listener (if enabled)	2000
username	Username if HTTP authentication is enabled	N/A
password	Password if HTTP authentication is enabled	N/A
http_method	HTTP method used to communicate with the device	GET
model	Appears under the Model field for the accessory	plugin
serial	Appears under the Serial field for the accessory	apiroute
manufacturer	Appears under the Manufacturer field for the accessory	author
firmware	Appears under the Firmware field for the accessory	version

Scheduling

When scheduling is enabled, the plugin will see if watering can be completed today by however many minutes before sunrise specified in sunriseOffset, if not, it will schedule the relevant time for the next day.

The day selected must match the following criteria for watering to place:

• Not a restricted day/month
• Forecasted rain for today and tomorrow not higher than threshold
• Forecasted low and high temperature higher than their respective thresholds

If adaptive watering is disabled, but scheduling remains enabled, each zone will be watered for a percentage (specified in zonePercentages) of the number of minutes specified in defaultDuration

The plugin schedules asynchronous zone watering times (no more than one zone on at a given time), as most systems are incapable of supplying sufficient pressure to water multiple zones simultaneously.

Start times will vary daily as a result of changing sunrise times.

Adaptive watering

When adaptive watering is enabled, a zone's total watering duration will be calculated as a percentage (specified in zonePercentages) of the calculation below:

highDiff = waterDay.max - highThreshold
lowDiff = highThreshold - waterDay.min
cloudPercentage = 100 - (waterDay.clouds / 3)
zoneMaxDuration = (((defaultDuration + (highDiff - lowDiff)) / 100) * cloudPercentage) - waterDay.rain

API Interfacing

Your API should be able to:

1. Return JSON information when it receives /status:

[
  {
    "zone": 1,
    "state": 0
  },
  {
    "zone": 2,
    "state": 0
  },
  {
    "zone": 3,
    "state": 0
  },
  ...
]

2. Set zone state when it receives:

/setState?zone=ZONE_INT_VALUE&value=INT_VALUE

Optional (if listener is enabled)

1. Update state following a manual zone override by messaging the listen server:

/state?zone=ZONE_INT_VALUE&value=INT_VALUE

Notes

• If you are using scheduling, the sprinkler controller should have an onboard auto-shutoff feature where the valve will automatically close after a period of time (e.g. 30 minutes) has passed so that valves are not left open if there was an error receiving the 'off message' from the plugin

• I am open to suggestions about new ways to calculate watering times for adaptive watering in place of the simple calculation currently implemented

• The watering times displayed to you within the homebridge log are rounded to make reading them easier due to JavaScript's floating point calculations. The real watering times are not rounded

• Your API key grants you access to 1000 API calls per day. The plugin will only make an API call once per day (as well as whenever homebridge starts up) so you shouldn't need to worry about running out of API calls

To-do

• Ensure the main service is set to In Use when a valve is active

• Set Program Mode to manual when user manually overrides valve

• Update Remaining Duration accordingly - for main service or for each valve?