# max7219.py - MAX7219驱动程序
from machine import Pin, SPI
import time

class Matrix8x8:
    def __init__(self, spi_bus=0, cs_pin=5, sck_pin=2, mosi_pin=3):
        """初始化MAX7219
        
        Args:
            spi_bus: SPI总线号
            cs_pin: 片选引脚
            sck_pin: 时钟引脚
            mosi_pin: MOSI数据引脚
        """
        # 寄存器地址定义
        self.REG_NOOP = 0x0
        self.REG_DIGIT0 = 0x1
        self.REG_DIGIT1 = 0x2
        self.REG_DIGIT2 = 0x3
        self.REG_DIGIT3 = 0x4
        self.REG_DIGIT4 = 0x5
        self.REG_DIGIT5 = 0x6
        self.REG_DIGIT6 = 0x7
        self.REG_DIGIT7 = 0x8
        self.REG_DECODEMODE = 0x9
        self.REG_INTENSITY = 0xA
        self.REG_SCANLIMIT = 0xB
        self.REG_SHUTDOWN = 0xC
        self.REG_DISPLAYTEST = 0xF

        # 初始化SPI
        self.spi = SPI(spi_bus,
                      baudrate=10000000,
                      polarity=0,
                      phase=0,
                      sck=Pin(sck_pin),
                      mosi=Pin(mosi_pin))
        self.cs = Pin(cs_pin, Pin.OUT)
        self.cs.value(1)  # 禁用芯片选择
        
        # 初始化显示
        self._write(self.REG_SHUTDOWN, 0x1)    # 正常工作模式
        self._write(self.REG_DISPLAYTEST, 0x0) # 正常显示模式
        self._write(self.REG_DECODEMODE, 0x0)  # 无解码模式
        self._write(self.REG_SCANLIMIT, 0x7)   # 显示所有数位
        self._write(self.REG_INTENSITY, 0x8)   # 中等亮度
        self.clear()                           # 清除显示

    def _write(self, register, data):
        """向MAX7219写入数据
        
        Args:
            register: 寄存器地址
             要写入的数据
        """
        self.cs.value(0)
        self.spi.write(bytes([register, data]))
        self.cs.value(1)

    def clear(self):
        """清除显示"""
        for i in range(8):
            self._write(i + 1, 0)

    def brightness(self, intensity):
        """设置亮度
        
        Args:
            intensity: 亮度值(0-15)
        """
        if 0 <= intensity <= 15:
            self._write(self.REG_INTENSITY, intensity)

    def pixel(self, x, y, state):
        """设置单个像素点
        
        Args:
            x: x坐标(0-7)
            y: y坐标(0-7)
            state: 状态(True/False)
        """
        if 0 <= x <= 7 and 0 <= y <= 7:
            reg = y + 1
            val = self._read_digit(reg)
            if state:
                val |= (1 << (7 - x))
            else:
                val &= ~(1 << (7 - x))
            self._write(reg, val)

    def _read_digit(self, digit):
        """读取数位的当前值（通过缓存）"""
        return self._digit_values[digit - 1] if hasattr(self, '_digit_values') else 0

    def fill(self, pattern):
        """使用图案填充显示
        
        Args:
            pattern: 8个字节的列表，每个字节代表一行
        """
        if len(pattern) == 8:
            for i in range(8):
                self._write(i + 1, pattern[i])

# 示例代码
def demo():
    # 创建MAX7219对象
    display = Matrix8x8()
    
    # 显示笑脸图案
    smile = [
        0b00111100,
        0b01000010,
        0b10100101,
        0b10000001,
        0b10100101,
        0b10011001,
        0b01000010,
        0b00111100
    ]
    
    # 显示图案
    display.fill(smile)
    time.sleep(2)
    
    # 显示动画效果
    for _ in range(3):
        for i in range(16):
            display.brightness(i)
            time.sleep(0.1)
        for i in range(15, -1, -1):
            display.brightness(i)
            time.sleep(0.1)
    
    # 清除显示
    display.clear()

if __name__ == '__main__':
    demo()