test_lcd_i2c_mcp23008_adafruit.py

#!/usr/bin/python
# Example script to show usage of MCP230xx GPIO extender to drive character LCD.

import sys
sys.path.append('./lib')
from Adafruit_CharLCD import Adafruit_CharLCD
from Adafruit_MCP230xx import MCP230XX_GPIO

# bus = 1         # Note you need to change the bus number to 0 if running on a revision 1 Raspberry Pi.
# address = 0x20  # I2C address of the MCP230xx chip.
# gpio_count = 8  # Number of GPIOs exposed by the MCP230xx chip, should be 8 or 16 depending on chip.

def init(bus=1, address=0x20, gpio_count=8):
    # Create MCP230xx GPIO adapter.
    mcp = MCP230XX_GPIO(bus, address, gpio_count)

    # Create LCD, passing in MCP GPIO adapter.
    lcd = Adafruit_CharLCD(pin_rs=1, pin_e=2, pins_db=[3,4,5,6], GPIO=mcp)

    lcd.clear()
    return lcd

def write_msg(lcd, msg):
    lcd.message(msg)


if __name__ == '__main__':
    lcd = init()
    write_msg(lcd, "  Adafruit 16x2\n  Standard LCD")