我想要一个micropython驱动st7920的程序

以下是一个基于Micropython的ST7920驱动程序：

from machine import Pin, SPI
import time

class ST7920:
    # Command list
    LCD_FUNCTION_SET = 0x30
    LCD_FUNCTION_SET_2 = 0x34
    LCD_DISPLAY_ON_OFF = 0x08
    LCD_ENTRY_MODE = 0x06
    LCD_CLEAR_SCREEN = 0x01
    LCD_SET_DDRAM_ADDRESS = 0x80

    def __init__(self, spi_bus=1, rs=16, rw=17, en=18, cs=5):
        self.spi_bus = spi_bus
        self.rs = Pin(rs, Pin.OUT)
        self.rw = Pin(rw, Pin.OUT)
        self.en = Pin(en, Pin.OUT)
        self.cs = Pin(cs, Pin.OUT)
        self.spi = None
        self.init_display()

    def init_display(self):
        self.spi = SPI(self.spi_bus, baudrate=1000000, polarity=1, phase=1)
        self.send_command(self.LCD_FUNCTION_SET)
        time.sleep_ms(5)
        self.send_command(self.LCD_FUNCTION_SET)
        time.sleep_us(200)
        self.send_command(self.LCD_FUNCTION_SET)
        self.send_command(self.LCD_FUNCTION_SET_2)
        self.send_command(self.LCD_ENTRY_MODE)
        self.send_command(self.LCD_DISPLAY_ON_OFF)
        self.clear_display()

    def clear_display(self):
        self.send_command(self.LCD_CLEAR_SCREEN)
        time.sleep_ms(5)

    def send_command(self, cmd):
        self.rs.off()
        self.rw.off()
        self.spi.write(bytearray([cmd]))
        self.en.on()
        self.en.off()

    def send_data(self, data):
        self.rs.on()
        self.rw.off()
        self.spi.write(bytearray([data]))
        self.en.on()
        self.en.off()

    def set_cursor(self, x, y):
        if y == 0:
            addr = x
        else:
            addr = 0x40 + x
        self.send_command(self.LCD_SET_DDRAM_ADDRESS | addr)

    def write_string(self, string):
        for char in string:
            self.send_data(ord(char))

    def write_char(self, char):
        self.send_data(char)

使用示例：

from st7920 import ST7920

lcd = ST7920()
lcd.write_string("Hello, World!")
lcd.set_cursor(0, 1)
lcd.write_string("ST7920 LCD")