1. CTY SAR FCPS Shawn Lupoli, Elliot Tan
Arduino LCD Lab
CTY SAR FCPS
Shawn Lupoli, Elliot Tan

2. Let’s understand what we are working with…

3. How does the LCD work?
Microcontroller has to manipulate several interface pins at once to control the display
Register select (RS) pin – controls where in memory you are writing data to
Read/Write (R/W) pin – selects reading or writing mode
Enable pin – enables writing to registers
8 data pins – states of these pins are the values the LCD is reading
Liquid Crystal library allows you to control LCD displays which are compatible with the Hitachi HD44780 driver 16 pin interface
Liquid Crystal simplifies two processes
Puts data that form the image into the data registers
Then puts instructions in the instruction registers

4. Visual of Connecting Arduino to LCD

5. Goal

6. Programming “Hello World” on LCD

7. “Hello World” Part 1 Include all necessary libraries
#include <LiquidCrystal.h>
Initializing global variables
The LCD itself needs to initialized as a LiquidCrystal object
“LiquidCrystal lcd(12, 11, 5, 3, 2)”
Setup()
lcd.begin(cols, rows) – initializes interface to LCD screen, then specifies the dimensions of the display
lcd.print(“Hello, World”) – prints text to the LCD

8. “Hello World” Part 2 Loop() Functions Examples
lcd.setCursor(col, row) – positions the LCD cursor, sets location where subsequent text written to LCD will be displayed
Millis() – returns the numer of milliseconds sine the Arduino board began running current program
Examples
lcd.setCursor(0, 1) – sets cursor to column 0, line 1
lcd.print(millis() / 1000) – prints number of seconds since reset

9. CODE

10. Building the LCD circuit

11. Supplies 1 Arduino Leonardo/Uno board 1 breadboard
6 short wires (2 red, 4 black)
4 medium wires (3 brown, 1 black)
5 long wires (1 red, 4 brown)
1 potentiometer
1 resistor (1 kΩ)
1 LCD
* Notes:
Wires are 22 or 24 AWG, solid
Short wires = 5 cm
Medium wires = 12 cm
Long wires = 16 cm

12. Diagram of LED Circuit

13. Connecting Code and Circuit

14. Putting it All Together
UPLOAD!
Remember to check for the flashing RX and TX lights, and a “Successful upload” message in your console
Understanding the process
LCD RS pin to digital pin 12
LCD Enable pin to digital pin 11
LCD D4 pin to digital pin 5
LCD D5 pin to digital pin 4
LCD D6 pin to digital pin 3
LCD D7 pin to digital pin 2
LCD R/W pin to ground

15. Troubleshooting Make sure to turn on the Potentiometer!
Make sure all wires are connected to the correct pin!
Questions?