Automated lawn irrigation with some valves and an Arduino Nano 33 IoT
August 21st, 2020
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There have been plenty of projects designed to automate lawn irrigation, however these normally refer to systems that open a single valve and turn on the sprinklers — all the sprinklers — at one time. Due to an irregularly shaped yard and a limited water supply, Sebastian Staacks wanted a bit more granular control.
Staacks’ setup consists of a half dozen Gardena valves, which are housed in underground boxes, while the brains and power supply are screwed to a wooden board on a wall in his garage. An Arduino Nano 33 IoT is employed to activate the sprinklers in six zones with an eight-channel relay bank. Relay channels 1 to 6 correspond to the valves controlling the sprinkler groups, the seventh is used for the main valve, and the eighth is saved for a “bonus” function that may be disclosed later.

The device operates over WiFi using MQTT via an OpenHAB installation. It also features a pair of buttons and a small OLED screen for manual interface, especially useful when he’s on vacation and someone else is taking care of the house.
[youtube https://www.youtube.com/watch?v=7ifaWxQd_Fk?feature=oembed&w=500&h=281]
Code for the build can be found on GitHub, and more details are available in Staacks’ blog post.
Website: LINK