The Arduino uses a shift register to interact with the keyboard’s 8×10 matrix, and the sketch translates any serial data it receives into the keypresses the clone is expecting.

He programs the Arduino bootloader into the chip, and then he’s using the Arduino Leonardo keyboard libraries. Bam! Check out the video below.

Watch the video below to learn more about his Arduino-based portable keypad that connects to your Arduino development board and offers the complete alphabet, numbers 0-9 as well as several commands.