* You probably also want to look at the schematic for the button pad breakout board https://www.sparkfun.com/datasheets/Components/Buttons/Button_Pad_Breakout.pdf
* You probably also want to look at the schematic for the button pad breakout board https://www.sparkfun.com/datasheets/Components/Buttons/Button_Pad_Breakout.pdf
and perhaps also http://www.dribin.org/dave/keyboard/one_html/