In this lesson we learn how to use LED and Push button in this 10 LED projects. Wiring diagram is shown, code is fully explained and demonstrated with multiple change of settings for each project. We read potentiometer's voltage and display voltage by turning each LED on to represent voltages. A Simple traffic light project. This code is part of video lecture. This project 7 code. this is an Arduino sktech where 4 LEDS turn ON and OFF in such a way that an LED is walking.