Data Sheet
56 
Lesson 22  LED bar graph display 
Overview 
In this lesson, you will learn how to control a LED bar graph in a row 
Components Required 
Name  Qty  Name  Qty 
UNO R3 or MEGA 2560  1  10KΩ Potentiometer  1 
220Ω Resistor  1  LED Bar Graph  1 
Breadboard  1  DuPont Wire  15 
Component Introduction 
The bar graph is made of  10 independent LEDs in a row. Internal 
schematic diagram for the LED bar graph shows in the right 
picture. In this lesson, we will use a potentiometer to change 
the input voltage of an analog pin. Then Arduino read the 
voltage and display the voltage level on the LED bar display. 
Wiring Diagram 
1 2 3 4 5 6 7 8 9 10
20 19 18 17 16 15 14 13 12 11
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