Lcd I2C - Custom Characters

LCD displays with an HD44780 controller support custom characters, which are stored in CGRAM (Character Generator RAM). These characters are defined using an 8-byte array, where each byte represents a row of a 5x8 pixel grid. By setting the pixels with binary values (1 for on, 0 for off), you can design unique symbols like faces, icons, or symbols.

ℹ️

If you have trouble creating custom characters, you can use a custom character generator.

// Include the library
#include "16x2-LCD-SOLDERED.h"

LCD lcd; // create LCD object


uint8_t happy[8] = {
    // happy face
    0b00000, 0b10001, 0b00000, 0b00000, 0b10001, 0b01110, 0b00000, 0b00000,
};

uint8_t wow[8] = {
    // wow face
    0b00000, 0b10001, 0b00000, 0b01110, 0b10001, 0b01110, 0b00000, 0b00000,
};

uint8_t anchor[8] = {
    // anchor bit array
    0b01110, 0b01010, 0b01110, 0b00100, 0b10101, 0b10101, 0b01110, 0b00100};

uint8_t snow[8] = {
    // snow bit array
    0b01000, 0b11101, 0b01011, 0b00001, 0b00100, 0b01110, 0b00100, 0b10000};

void setup()
{
    lcd.begin();     // begin the LCD
    lcd.backlight(); // turn on the backlight

    lcd.createChar(0, happy);  // create happy face on char 0
    lcd.createChar(1, wow);    // create wow face on char 1
    lcd.createChar(2, anchor); //  create anchor bit array on char 2
    lcd.createChar(3, snow);   //  create snow bit array on char 3


    lcd.write(0); // write happy face (char 0)
    lcd.write(1); // write wow face (char 1)
    lcd.write(2); // write anchor bit array (char 2)
    lcd.write(3); // write snow bit array (char 3)
}

void loop()
{
}

lcd.createChar()

Stores a custom character in the LCD's CGRAM (Character Generator RAM). The 'location' parameter specifies the slot (0-7) where the character will be stored, and 'charmap' is an 8-byte array that defines the pixel pattern of the character.

Returns value: None

Function parameters:

Type	Name	Description
uint8_t	location	The slot (0-7) in the CGRAM where the custom character will be stored.
uint8_t[]	charmap	An 8-byte array representing the pixel pattern of the custom character.

LCD Preview

Custom_Chars.ino

Example file for displaying custom characters using the LCD I2C display