IOError：[Errno 5]输入/输出错误Raspberry pi B +型号+ Adafruit LCD +键盘

Question

我正在使用Raspberry pi B +模型和Adafruit 16x2字符LCD加上用于树莓派的键盘https://learn.adafruit.com/adafruit-16x2-character-lcd-plus-keypad-for-raspberry-pi/usage 当我写完最后一步时，我在指南中做了所有步骤

sudo python char_lcd_plat.py 

终端给了我这个错误：

Traceback (most recent call last):
  File "char_lcd_plate.py", line 9, in <module>
     lcd = LCD.Adafruit_charLCDPlate()
  File "build/bdist.linux-armv6l/egg/Adafruit_CharLCD/Adafruit_CharLCD.py", line 432, in __init__
  File "build/bdist.linux-armv6l/egg/Adafruit_GPIO/MCP230xx.py", line 150, in __init__
   File "build/bdist.linux-armv6l/egg/Adafruit_GPIO/MCP230xx.py", line 46, in __init__
   File "build/bdist.linux-armv6l/egg/Adafruit_GPIO/MCP230xx.py", line 130, in write_iodir
  File "build/bdist.linux-armv6l/egg/Adafruit_GPIO/I2C.py", line 95, in writelist
IOError: [Errno 5] Input/output error

有人可以帮我吗？ I2C在smbus上运行[1]

由于