How to Build a 10-Key Serial Keypad. Creating & Using Asynchronous Serial Solutions: How to create your own Serial Keypads. This project uses PicBasic Pro, and the PIC16C620A microcontroller to build a 10-key serial keypad. The PIC16C620A only costs $2.50 each in single quantities, and the keys are simple normally-open, push-button switches. Build a user input keypad for your next basic stamp or PIC design and use a single I/O-pin for the interface. schematic diagram

How to Build a 10-Key Serial Keypad. Creating & Using Asynchronous Serial Solutions: How to create your own Serial Keypads. This project uses PicBasic Pro, and the PIC16C620A microcontroller to build a 10-key serial keypad. The PIC16C620A only costs $2.50 each in single quantities, and the keys are simple normally-open, push-button switches. Build a user input keypad for your next basic stamp or PIC design and use a single I/O-pin for the interface.