Filling tank with water is very boring task. Standing and watching it until it fills up is a waste of time especially if volume is quite big. IT is better to leave this task for automatics. There can be several ways of controlling filling process. One is to use timer which shuts valve after predefined time period. Another method relies on water level sensor which detect when water level reaches some level. Second method is more accurate, but needs more setup. Kyle was asked to construct water filling timer which would turn off valve after some time.
In this setup user starts timer by opening valve. After time runs our, valve is shut. So user has to determine the time needed to fill pool with water and program this value in to controller. Of course things can happen, for instance water pressure drop what would lead to underfill. Despite this, system works great and reliably. Controller is built around Attiny microcontroller which accepts start input via single button. Valve is controller by using TLC226T TRIAC which drives 24V solenoid. Couple LED indicators indicate timer status. The nice thing about this controller, is its enclosure which was 3D printed. It looks great, it has it connectors populated for convenient wire attachment.