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 ...

Arduino Keypad Door Automation. November 1, 2013 by James Hobson 45 Comments ... The entire build is made out of scrap parts he had lying around: some DVD’s, a bit of wood, an allen key, ...