A keypad is one of the most commonly used input devices in microprocessor applications. In a standard keypad wired as an X-Y switch matrix, normally-open switches connect a row to a column when ...

[Tony] has developed a method of using a state machine to validate keypad inputs. His method checks the commands character by character as they are entered in by a 16 button keypad. State machines are ...

Premier space exploration disaster simulator, Kerbal Space Program, is fun to play with regular controls, but it can be improved with this DIY build that lets you launch ships with a giant red button.