connect to the column C1-C3 pinouts of the keypad Next is a project example, where the Arduino is instructed to do something based on a correct key (secret number) being entered into the keypad, ...

If you’ve scavenged some random keypads and want to reuse them in a project without the hassle of figuring out the pinouts, then [Cliff Biffle] has an interface module for you. The Keypad Go ...