This project allows you to automate the filling of water containers. In this case the need was to stop filling a horse water tank and automatically stop when it has been filled. A few stainless steel clamps are used to sense the water by conduction. The circuit is running off a 9 volt battery, it is powerful enough to activate the 12 volt relay and a voltage divider is used to make the 5 volts that the microcontroller needs.
“This is a very simple project that only uses a few electrical components and some PVC pipe. This is the first project that I have built using an ATTiny 85. It is a very powerful little chip and I will probably have many more projects that use it. An Arduino can be used in place of the ATTiny85 and the same code should work.”