2.6 Display Characters

Now, we will explore the fascinating world of character display using the I2C LCD1602 module.

Through this project, we will learn how to initialize the LCD module, set the desired display parameters, and send character data to be displayed on the screen. We can showcase custom messages, display sensor readings, or create interactive menus. The possibilities are endless!

By mastering the art of character display on the I2C LCD1602, we will unlock new avenues for communication and information display in our projects. Let’s dive into this exciting journey and bring our characters to life on the LCD screen

Required Components

In this project, we need the following components.

It’s definitely convenient to buy a whole kit, here’s the link:

Name

ITEMS IN THIS KIT

LINK

ESP32 Starter Kit

320+

ESP32 Starter Kit

You can also buy them separately from the links below.

COMPONENT INTRODUCTION

PURCHASE LINK

ESP32 WROOM 32E

BUY

ESP32 Camera Extension

-

Jumper Wires

BUY

I2C LCD1602

BUY

Available Pins

Here is a list of available pins on the ESP32 board for this project.

Available Pins

Usage Description

IO21

SDA

IO22

SCL

Schematic

../../_images/circuit_2.6_lcd.png

Wiring

../../_images/2.6_i2clcd1602_bb.png

Code

Note

  • Open the 2.6_lcd1602.ino file under the path of esp32-starter-kit-main\c\codes\2.6_lcd1602.

  • After selecting the board (ESP32 Dev Module) and the appropriate port, click the Upload button.

  • Always displaying “Unknown COMxx”?

  • The LiquidCrystal I2C library is used here, you can install it from the Library Manager.

    ../../_images/lcd_lib.png

When this program is uploaded, the I2C LCD1602 will display the welcome message, “Hello, Sunfounder!”, for 3 seconds. After that, the screen will show a “COUNT:” label and the count value, which increments every second.

Note

If the code and wiring are correct, but the LCD still fails to display any content, you can adjust the potentiometer on the back to increase the contrast.

How it works?

By calling the library LiquidCrystal_I2C.h, you can easily drive the LCD.

#include <LiquidCrystal_I2C.h>

Library Functions：

  • Creates a new instance of the LiquidCrystal_I2C class that represents a particular LCD attached to your Arduino board.

    LiquidCrystal_I2C(uint8_t lcd_Addr,uint8_t lcd_cols,uint8_t lcd_rows)

    • lcd_AddR: The address of the LCD defaults to 0x27.

    • lcd_cols: The LCD1602 has 16 columns.

    • lcd_rows: The LCD1602 has 2 rows.

  • Initialize the lcd.

    void init()

  • Turn the (optional) backlight on.

    void backlight()

  • Turn the (optional) backlight off.

    void nobacklight()

  • Turn the LCD display on.

    void display()

  • Turn the LCD display off quickly.

    void nodisplay()

  • Clear display, set cursor position to zero.

    void clear()

  • Set the cursor position to col,row.

    void setCursor(uint8_t col,uint8_t row)

  • Prints text to the LCD.

    void print(data,BASE)

    • data: The data to print (char, byte, int, long, or string).

    • BASE (optional): The base in which to print numbers.

      • BIN for binary (base 2)

      • DEC for decimal (base 10)

      • OCT for octal (base 8)

      • HEX for hexadecimal (base 16).