Smart sprinklers controllers can cost $200 or more and there is no way to customize them. For around $50 you can build your own sprinkler controller with Nerves and have the freedom to customize it in any way you want. I will walk you through the software and hardware you need to get going, including sensors that can make your controller smarter than any available off-the-shelf today.
I am a reformed graphic designer that got my start in web development 15 years ago. I have made a career in front-end development, PHP, Rails, and for the last year or so, in Elixir. I am a contributor to hex and hex.pm and in my spare time I tinker with hardware projects.