LCD1602 Go Library

Yet another Go library for controlling LCD1602 displays via I2C in 4-bit mode.

Features

• Display Configuration: Support for various display sizes (16x1, 16x2, 16x4, 20x1, 20x2, 20x4) and font options (5x8 and 5x10)
• Text Display: Print text at specific positions or write from current cursor position
• Cursor Control: Set cursor position, move to home, and enable/disable/toggle cursor visibility, enable/disable/toggle blinking at cursor position
• Display Control: Clear display, turn display on/off
• Backlight Control: Enable, disable, or toggle LED backlight
• Custom Characters: Upload custom characters (5x8 pixel patterns) to CGRAM locations 0-7
• Raw Character Access: Direct access to character codes for special characters and custom patterns

Demo

Run the included demo (for 1602 version of display) to see the library in action:

go run main.go

This initializes the LCD, says "Hello!", displays some ASCII art, updates the current time every second, and even wakes up Cthulhu!

To build the demo for your architecture use make commands.

View all available build targets:

make help

For example, build for Raspberry Pi model 1:

make arm6

This will build a binary named lcd-demo-armv6 for ARMv6 architecture.

Example: Custom Characters

Create and display custom characters using UploadCustomChar.

This code will display two cthulhus nearby.

package main

import (
	"log"
	"github.com/realfatcat/lcd1602"
)

func main() {
	// Initialize LCD
	lcd, err := lcd1602.New(
		lcd1602.DefaultDevice,
		lcd1602.DefaultAddress,
		16, 2, lcd1602.Font5x8, true,
	)
	if err != nil {
		log.Fatal(err)
	}
	defer lcd.Close()

	// Define a custom cthulhu character (5x8 pixels)
	// Each byte represents one row, bits 0-4 represent the 5 pixels
    var cthulhu = [8]byte{
        0b01110,
        0b11111,
        0b10101,
        0b11111,
        0b01110,
        0b11111,
        0b10101,
        0b10101,
    }

	// Upload to CGRAM location (3), possible locations 0-7
	if err := lcd.UploadCustomChar(3, cthulhu); err != nil {
		log.Fatal(err)
	}

	// Display the custom character at position (0, 0)
	// Use PrintRAW or WriteRAW with the location byte (3)
	if err := lcd.PrintRAW(3, 0, 0); err != nil {
		log.Fatal(err)
	}

	// Or write it at the current cursor position
	if err := lcd.WriteRAW(3); err != nil {
		log.Fatal(err)
	}
}