Pre-requisite:

1. Arduino
2. Basic circuit knowledge
3. How does a button work

Objectives:

1. To understand how to form a keypad using less General Purpose IO. (Not each button each pin)

Descriptions:

1. Please refer to : http://esd.cs.ucr.edu/labs/decode_key/decode_key.html
   
   

   iFrame
   src http://esd.cs.ucr.edu/labs/decode_key/decode_key.html width 1000 height 400