1. LCD

2. Purpose
LCD screens can be used by an Arduino to display numbers and text

3. Wiring The screens communicate over a specific protocol called I2C
It uses two communications pins, SDA and SCL
On UNO boards, the A4 and A5 pins perform this task

4. Wiring

5. Wiring A4 and A5 SDA and SCL CIJE boards contain both:
Either can be used

6. Libraries
LCD’s contain 1,000’s of tiny independently controlled pixels
Coding these independently would be impossible
Instead we use a library
Libraries can contain vast amounts of sub-coding, easily accessible using simple keywords
For example: Tell Arduino to print the letter “A”, and the library inserts the coding necessary to control those pixels

7. Libraries
The LCD library can be downloaded at theCIJE.org/Arduino

8. Libraries
The downloaded file, in the form of a zip file, must be installed

9. Coding Within the void loop(), some commands you can use are:
lcd.backlight(); // will turn on the blue backlight
lcd.noBacklight(); // will turn off the blue backlight
lcd.clear(); // will clear the screen
lcd.setCursor(0,0); // move the cursor to cord. (x,y)
lcd.print("Hello"); // prints "Hello"
lcd.print(x); // prints the value of x

10. Coding Example If you had an integer "x" and it was equal to 96:
lcd.clear();
lcd.setCursor(0,0);
lcd.print("Hello, ARDUINO");
lcd.setCursor(0,1);
lcd.print(x);
Would display:

11. LAB
Complete the LCD lab in
Unit 12 of the textbook