Irrigation + Arduino = Irrighino!
As the Internet of Things continues to blossom, there will surely be more and more ways for you to water your lawn and gardens. Whereas some commercial units can set you back thousands of dollars, Makers like Luca Dentella are finding much more affordable and just as effective solutions with the help of low-cost hardware.
Meet Irrighino, a complete watering system based on the mighty Arduino Yún (ATmega32U4) along with some other off-the-shelf components. The main features of the DIY irrigation platform include a configurable number of solenoid valves, an AJAX web interface, a weekly schedule, and manual activation/deactivation.
In terms of hardware, the Yún is connected to the switch panel (with three physical switches and status LEDs), a rain sensor and a relay shield to control the solenoid valves. The Arduino also links to your home’s Wi-Fi network, allowing you to open its web-based interface on a mobile device or PC.
The drag-and-drop, Excel-like interface is divided into three tabs: ‘runtime’ to manage the system, ’setup’ to configure the scheduling, and ‘events’ to view system logs. While scheduling the Irrighino is just as easy as putting appointments into your Outlook calendar, it is possible to manually command the water solenoids as well.
“I put the Yún in a plastic enclosure for DIN rails (6 units). When closed, I noticed that the Wi-Fi signal strength was very poor… I therefore decided to add an USB Wi-Fi adapter with an external antenna,” Dentella explains. “I mounted the antenna outside the enclosure and connected it to the adapter with an RP SMA male to female cable.”
A relay module is mounted to a dedicated box, while Irrighino’s power is supplied by a pair of transformers — a 5V for the electronic circuitry and a 24V for the solenoid valves. The two transformers along with the main switch are located in different DIN rail enclosures.
As for outside in the lawn, the watering system itself is divided into zones, each one paired to a solenoid valve. What’s more, a commercial rain sensor acts as a switch surrounded by a spongy material. When this material absorbs the rain, it begins to expand and triggers the switch. The Arduino sees the sensor as a simple digital input.
The software behind Irrighino is broken down into three elements: the web interface (based jQuery, jQuery DataTables and jQuery WeekCalendar), the backend subsystem (based on PHP and SQLite) and the sketch running on the ATmega32U4. Dentella has made all of the code available on GitHub, and provides a detailed explanation of how to install, configure and customize the
Intrigued? Check out the Maker’s entire project here.