from machine import Pin, I2C
import time
import mcp23017

SCL = 17
SDA = 16

# Registers voor de MCP23017
IODIRA = 0x00
IODIRB = 0x01
GPIOA  = 0x12
GPIOB  = 0x13

# I2C 設定
i2c = I2C(0, scl=Pin(SCL), sda=Pin(SDA), freq=400000)

# FORCEER een scan om te kijken of de bus leeft
print("Bus scan:", [hex(d) for d in i2c.scan()])

mcp = mcp23017.MCP23017(i2c, 0x21)

# property interface 8-bit
mcp.mode = 0x0000

while True:
  # turn LED on
  mcp.gpio = 0x0000
  time.sleep_ms(500)
  
  # turn LED off
  mcp.gpio = 0xFFFF
  time.sleep_ms(500)

  leds = 1
  for i in range(16):
    # 將要控制的燈狀態寫入 PCF8575
    mcp.gpio = 0x0000
    time.sleep_ms(100)
    mcp.gpio = leds
    time.sleep_ms(100)

    # 計算要打開的燈的位置
    leds = leds << 1