Keypads are small keyboards that are used to enter numeric or alphanumeric data to microcontroller systems. Keypads are available in a variety of sizes and styles from 2 × 2 to 4 × 4 or even bigger.
In this project, the PmodKYPD module is used. This is a 4 × 4 keypad with 2 × 6 pins and keys labelled 0–9 and A–F. Figure 7.143
shows a picture of the PmodKYPD module.
This is a simple project where the Serial Monitor displays the key pressed on the keypad.