This is a very different project that aims at creating an Arduino based shield for battery-operated sprinkler. Although the work on creating an Arduino based controller for the sprinkler is in development stage, this one is ready to buy shield. The shield is designed to work with battery-operated sprinkler waves. The valves inside utilize a latching solenoid, which just draws power when you open or close the valve, and does not draw power in the event that it stays in the same state. Therefore, they are very efficient and are ideal for battery operated controllers.
Moreover, the shield can also be stacked with other shield such as WiFi to provide web control. There’s an on-boost converter which helps in generating high voltage require to open or close the valve. An H-Bridge has also been made by using 4 MOSFET switches to generate voltage in both polarities (Ex: -9V and 9V). Overall an exciting application of both analog as well as digital electronics. If you are interested in the shield you can buy it or even make it yourself with the help of manual available on the project website.