Arduino Port Manipulation (Registers Access) Tutorial & Examples
How do I read the state of 3 output pins on an Arduino UNO and then NAND them together? - Stack Overflow
How to use a potentiometer connected to arduino to increment and decrement a variable. It includes also the description of the map function used to remap range of integers value
Interfacing Common Anode 7 seven segment display with arduino uno and Printing Numbers/Alphabets on it