Using eight digital inputs, this circuit simplifies decoding of the common membrane 4x4 keypad matrix and eliminates the traditional requirement of scanning rows or columns. Any X-Y switch matrix, ...

One style of low-profile keypad assembly is the conventional flexible membrane keypad where the switch circuitry is screen-printed. Silver conductive polymer inks are printed onto 1.25 mm (0.005 ...

This How-To is the first in a series of construction instructions for a project titled The Magic Phone. I was inspired by the Port-O-Rotary from Spark Fun but wanted to take the project to the next ...

In most keypads, pressing a key closes a contact that bridges two lines in an xy matrix. If you use a microcontroller to detect a key closure, checking the states of (x+y) lines requires an equal ...