Simple single zone sprinkler controller using ESP Home and a generic ESP8266 Wi-Fi Relay Module.
This uses the Sprinkler Controller component from ESPHome.io.
I have mine integrated with HomeAssistant for control, scheduling, and weather monitoring (rain detection, hot weather etc.)
An example config file can be found here: sprinkler-controller-simple.yaml
The Sprinkler Controller component is extremely flexible and extendable to many complex configurations.
I use a generic ESP8266 module that is integrated with a relay board
I was able to get mine from Jaycar in Australia, but you can get them extremely cheaply online from many sources.
https://www.jaycar.com.au/smart-wi-fi-relay-main-board/p/XC3804
Any 24v irrigation solenoid will work, I'm using a 19 mm Mini Barb Solenoid.
I wanted to use a single power supply for the solution, and as irrigation solenoids are usually 24VAC, I simply used a basic LM259 AC to DC Converter Module to power the relay board.
These can be programmed OTA, but depending on what the device is initially programmed with, it may need an initial flash to work.
The ESP8266 can be programmed with a standard USB to Serial Adaptor via the headers on the relay board, or as the module is detachable, it can be removed and connected to a ESP test/programming board.
