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LCD

README.md

LCD Universal Driver Documentation

Overview

This document explains how to use the LCD universal driver module to achieve various display functions. This driver provides a rich set of drawing and display interfaces, supporting basic graphic drawing such as points, lines, rectangles, and circles, as well as the display of characters, Chinese characters, images, etc.

Main Features

  • Supports basic graphic drawing: points, lines, rectangles, circles
  • Supports ASCII character display (8x16, 16x24)
  • Supports Chinese character display (16x16, 16x24, 24x24)
  • Supports image display (JPG format or RGB data)
  • Supports clearing the screen and area filling
  • Supports RGB565 color format
  • Provides color conversion tool functions

Quick Start

1. Create an LCD subclass

from machine import LCD
from usr import Peripheral_LCD


class MyLCD(Peripheral_LCD):
    def __init__(self):
        # Initialize the actual LCD device 
        self._lcd = LCD()
        self._lcd.lcd_init()
        self._lcd_w = 240  # LCD width
        self._lcd_h = 320  # LCD height 
        # Call the initialization of the parent 
        class super().__init__(self)
# Create an LCD instance
lcd = MyLCD()

2. Basic Drawing Operations

# Clear screen to white 
lcd.Clear(0xFFFF)

# Draw a red rectangle 
lcd.DrawRectangle(50, 50, 150, 150, 0xF800)

# Draw a blue circle 
lcd.DrawCircle(120, 160, 50, 0x001F)

# Draw the green diagonal line 
lcd.DrawLine(0, 0, 239, 319, 0x07E0)

3. Text Display

# Display ASCII string 
lcd.ShowAsciiStr(10, 10, 8, 16, "Hello World!" , 0x0000, 0xFFFF)

# Display Chinese characters
lcd.lcd_show_chinese_str(10, 30, 16, 16, "Chinese Test", 0x0000, 0xFFFF)

API Interface Description

DrawPoint(x, y, color)

Draw a point at the designated position.

Parameter Explanation:

  • x: X coordinate
  • y: Y coordinate
  • color: RGB565 color value

Clear(color)

Clear the screen using the specified color.

Parameter Explanation:

  • color: RGB565 color value

Fill(x_s, y_s, x_e, y_e, color)

Fill the specified rectangular area.

Parameter Explanation:

  • x_s: Initial X coordinate
  • y_s: Initial Y coordinate
  • x_e: End X coordinate
  • y_e: End Y coordinate
  • color: RGB565 color value

DrawLine(x0, y0, x1, y1, color)

Draw a straight line.

Parameter Explanation:

  • x0, y0: Starting coordinates
  • x1, y1: Ending coordinates
  • color: RGB565 color value

DrawRectangle(x0, y0, x1, y1, color)

Draw a rectangular border.

Parameter Explanation:

  • x0, y0: Top-left coordinate
  • x1, y1: Bottom-right coordinate
  • color: RGB565 color value

DrawCircle(x0, y0, r, color)

Draw a circle.

Parameter Explanation:

  • x0, y0: Coordinates of the center of the circle
  • r: Radius
  • color: RGB565 color value

ShowChar(x, y, xsize, ysize, ch_buf, fc, bc)

Display individual characters (supporting Chinese characters and ASCII).

Parameter Explanation:

  • x, y: Display position
  • xsize, ysize: Character size
  • ch_buf: Character bitmap data
  • fc: Foreground color (RGB565)
  • bc: Background color (RGB565)

ShowAscii(x, y, xsize, ysize, ch, fc, bc)

Display ASCII characters.

Parameter Explanation:

  • x, y: Display position
  • xsize, ysize: Character size
  • ch: ASCII character
  • fc: Foreground color (RGB565)
  • bc: Background color (RGB565)

ShowAsciiStr(x, y, xsize, ysize, str_ascii, fc, bc)

Display the ASCII string.

Parameter Explanation:

  • x, y: Starting position
  • xsize, ysize: Character size
  • str_ascii: ASCII string
  • fc: Foreground color (RGB565)
  • bc: Background color (RGB565)

ShowJpg(name, start_x, start_y)

Display JPG image.

Parameter Explanation:

  • name: File name of the image
  • start_x, start_y: Display position

lcd_show_chinese(x, y, xsize, ysize, ch, fc, bc)

Display a single Chinese character.

Parameter Explanation:

  • x, y: Display position
  • xsize, ysize: Character size
  • ch: Chinese character
  • fc: Foreground color (RGB565)
  • bc: Background color (RGB565)

lcd_show_chinese_str(x, y, xsize, ysize, str_ch, fc, bc)

Display the Chinese character string.

Parameter Explanation:

  • x, y: Starting position
  • xsize, ysize: Character size
  • str_ch: Chinese character string
  • fc: Foreground color (RGB565)
  • bc: Background color (RGB565)

lcd_show_image(image_data, x, y, width, height)

Display the RGB data image.

Parameter Explanation:

  • image_data: RGB565 格式的图片数据
  • x, y: Display position
  • width, height: Image size

lcd_show_image_file(path, x, y, width, height, h)

Display image files (supporting segmented display of large images).

Parameter Explanation:

  • path: Path of the image file
  • x, y: Display position
  • width, height: Image size
  • h: Segmentation height (it is recommended that widthh2 < 4096)

get_rgb565_color(r, g, b)

RGB888 to RGB565 color conversion.

Parameter Explanation:

  • r: Red component (0 - 255)
  • g: Green component (0 - 255)
  • b: Blue component (0 - 255)

Return Value:

RGB565 color value

Application Example

Create a digital clock interface

def digital_clock(lcd):
    # Clear screen to a dark blue color 
    lcd.Clear(0x0019)

    # Draw the outer frame of the clock 
    lcd.DrawRectangle(50, 50, 190, 110, 0xFFFF)
    lcd.Fill(51, 51, 189, 109, 0x0000)

    # Display time label 
    lcd.ShowAsciiStr(60, 60, 8, 16, "TIME:", 0xFFFF, 0x0000)

# Updated Time Display 
while True:
    # Obtain the current time 
    current_time = "12:34:56"

    # Clear Old Time 
    lcd.Fill(100, 60, 180, 75, 0x0000)

    # Display new time 
    lcd.ShowAsciiStr(100, 60, 16, 24, current_time, 0xFFFF, 0x0000)

    utime.sleep(1)

# Usage Example 
lcd = MyLCD()
digital_clock(lcd)

Display the sensor data dashboard

def sensor_dashboard(lcd, temp, humi, press):
    # Clear Screen 
    lcd.Clear(0xFFFF)

    # Display Title
    lcd.lcd_show_chinese_str(80, 10, 24, 24, "Environmental Monitoring", 0x0000, 0xFFFF) 
    # Temperature Display
    lcd.lcd_show_chinese_str(30, 50, 16, 16, "Temperature:", 0x0000, 0xFFFF) lcd.ShowAsciiStr(80, 50, 16, 24, "{:.1f}°C".format(temp), 0xF800, 0xFFFF)

    # Humidity Display
    lcd.lcd_show_chinese_str(30, 90, 16, 16, "Humidity:", 0x0000, 0xFFFF) lcd.ShowAsciiStr(80, 90, 16, 24, "{:.1f}%".format(humi), 0x001F, 0xFFFF)
    
    # Pressure Display
    lcd.lcd_show_chinese_str(30, 130, 16, 16, "Pressure:", 0x0000, 0xFFFF) lcd.ShowAsciiStr(80, 130, 16, 24, "{:.1f}hPa".format(press), 0x07E0, 0xFFFF)

    # Draw a divider line 
    lcd.DrawLine(20, 170, 220, 170, 0x0000)

    # Status Indication
    status = "Normal" if 18 <= temp <= 28 and 40 <= humi <= 60 else "Exception"
    color = 0x07E0 if status == "Normal" else 0xF800
    lcd.lcd_show_chinese_str(80， 190， 16， 16， "Status： {}".format(status)， color， 0xFFFF) 

    # Usage Example
    sensor_dashboard(lcd, 25.5, 45.2, 1013.2)

Common Issues Troubleshooting

  • Verify if the coordinates are beyond the screen boundaries
  • Ensure that the image data is in the RGB565 format
  • Use a conversion tool to preprocess the image