Traditionally, interfacing a microcontroller with an n-by-m keypad required n + m of the microcontroller's I/O pins for keypad scanning. Keypad designs that conserve microcontroller pins have been ...

A PIC16877 microcontroller is used to connect in particular to a 4X5 keypad which can also be connected with logic and analogue circuits. A PIC16877 microcontroller is used to connect in particular to ...

16-button keypads have a clever method of encoding their data into 8 pins. Pins are mapped to four rows and four columns on the keypad. A user reads the keypad by bringing each row up to logic: HIGH, ...

What can you do with ten buttons and ten lights? A lot. [Andrew] and [Nathan] found a collection of Hale Research keypads being thrown out, and decided to host the Keypad Contest. The goal of the ...