Maybe smart ESPboy flower waterer is a bit overengineered, but it turned out cool
You can set watering intervals and limits on soil moisture, run time, and amount of water supplied. Automatically detects if you run out of water. The RTC3231 alarm clock turns ESPboy on and off, saving battery life. Powered by an external battery, so it's not afraid to leave the sprinkler on for long periods of time. I can add WiFi uploads of all the watering statistics to thingspeak.com, for example, to see on the phone how the watering is going. But perhaps I will add it later. While I'm bored with it)