RainBuddy

The custom IFTTT Applet is called RainBuddy - Public.

Enter one version of the Applet that calls the function Rainonoff with the value "Rain" for when tomorrow's weather calls for Rain, and one version of the Applet that calls the function Rainonoff with the value "Dry" when tomorrow's weather calls for Clear (or just Cloudy - your choice).

Future things to work on / develop on this project include:

1) A purpose built device with a custom PCB - this will have a much lower cost (possibly well under $20 cost), and could add small features such as a battery, which could re-charge from the 24VAC power line when running, and contain its own antenna.

2) Custom phone App to access features / states of the RainBuddy

3) An inline current meter - this would allow the RainBuddy to most probably figure out the watering schedule, number of zones, and record this. It could then modify each zone independently, shortening the water times if it hasn't been that hot, for example, and even notify the user if their schedule doesn't match the recommended local schedule.

This project uses both IFTTT and IFTTT's DO Button App as its interface. This makes it easy for anyone to set up without any coding. If someone is unfamiliar with IFTTT, the functions that are available will show up in your IFTTT account after you have flashed the code (under Files section) to your Particle Photon, and linked Particle to your IFTTT acccount. Also, download the "DO Button" App by IFTTT.

Then set up the following Do Button - this will allow you to manually turn the RainBuddy On or Off.

1) DO App
Set up a New Recipe, under the Particle Channel choose:

A) Create a new Recipe
B) Give it a new title such as "Let sprinklers run" or "Sprinklers on normal" or "RainBuddy On"
C) Under "Then call a function", a list of functions will appear
D) Choose Sprinkonoff from the list
E) Under "with input (Function input)" - clear out any text in the box and enter [On] - (Copying the uppercase "O" but using no brackets ! - just the word On.
F) Hit the "Add" Button and you're done.

Repeat all of the above exactly, except enter the Title "Rainbuddy Off" or "Turn off sprinklers", and, in step E, enter the word Off (Capital "O").

Voila - you will have 2 buttons on your phone that can manually turn the RainBuddy On - meaning let the Sprinklers turn on their normal schedule, or RainBuddy Off - meaning don't let the Sprinklers run until you turn them back on.

2) IFTTT
I have created a custom function in IFTTT called RainBuddy, which gets tomorrow's weather forecast from IFTTT's Weather Underground channel, and then calls the right function on the RainBuddy when it is going to rain.

Installation of the device is easy.

Here is the before photo of a standard Sprinkler controller wired to 4 zones / valves. The white wire is the "COM" wire, common to all zones.

Here we interrupt the COM line with a relay connected to a Particle Photon, creating a WiFi enabled control system.

Installation is easy.
The project box shown is a sample box - the final device, which would be built with a custom PCB, would be much smaller.

Completed writing of the core section of the code.

Includes functions for:

- State tracking
States for Rain delay, Winter delay, and User on / off.
The User state will override all others so that the User can simply turn off the device and let the sprinkler controller function normally, or turn it on manually to stop the sprinklers should they choose.

- External Functions for IFTTT (Designed to integrate to Weather Underground App)

- Internal Functions for turning relays on and off.

Hardware hookups:
The prototype system uses a relay which is connected as Normally Closed (this is not the most common way to hook up Relays). This is so that if the unit fails, it fails in way that the sprinklers would continue to function normally - you would just loose the extra features of the RainBuddy device.