Designers of microcontroller-based products that require a keypad for user data entry can select from dedicating an input line for each key, continuously polling the keypad's x and y lines, or ...

Matrix keyboards are commonas an input device in microcontroller-based projects. A conventionalway of connecting a matrix keyboardto a microcontroller is to use multipleI/O pins of the MCU. The MCU ...

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 ...

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, ...