I i'm using it to fill my Coffeemaker with water. This way its a little bit more fun and i always get the same amount of water.
Its a simple project, and it's a good excuse to play with a PIC10F, one really small micro-controller. Code is written in C, a nice way to start with it.
It interfaces with the user blinking one led. so you can chose how much time the valve will open ( giving a good control on the amount of water). On the current firmware settings ( and with my valve) are for 1-2-3-4 cups of coffee ( i have a big cup, 300ml).
Just keep in mind that this button can be used for other uses.
The design (and problems that where solved) are on the next page, but if you just want to build this thing go to the building instructions page and download the project files.
Arthur Benemann 2011 Brazil
Step 1: In the beginning...
As always a good pile of junk it's great for this, a big yellow button and a water valve from a washing machine ( both in the pictures below).
Things need to be as simple as possible so a small micro-controller would be perfect. Luckily i had some spare PIC10F206 on my parts box. A 100mA transformer and a 78L05 would do the power supply, and a relay to control the valve ( mains power).
All parts are set up, now the board.... ( next page)