Resolve adafruit#30 adafruit#31 adafruit#32 by fixing MCP230xx_GPIO class parameter order and adding CharLCD with MCP230xx example.

Author: tdicola

Adafruit_CharLCD/Adafruit_MCP230xx.py

@@ -0,0 +1 @@
+../Adafruit_MCP230xx/Adafruit_MCP230xx.py

Adafruit_CharLCD/LCD_MCP230XX_test.py

@@ -0,0 +1,18 @@
+#!/usr/bin/python
+# Example script to show usage of MCP230xx GPIO extender to drive character LCD.
+
+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.
+
+# 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()
+lcd.message("  Adafruit 16x2\n  Standard LCD")

Adafruit_MCP230xx/Adafruit_MCP230xx.py

@@ -40,9 +40,9 @@ class Adafruit_MCP230XX(object):
     OUTPUT = 0
     INPUT = 1
 
-    def __init__(self, address, num_gpios):
+    def __init__(self, address, num_gpios, busnum=-1):
         assert num_gpios >= 0 and num_gpios <= 16, "Number of GPIOs must be between 0 and 16"
-        self.i2c = Adafruit_I2C(address=address)
+        self.i2c = Adafruit_I2C(address=address, busnum=busnum)
         self.address = address
         self.num_gpios = num_gpios
 
@@ -162,7 +162,7 @@ class MCP230XX_GPIO(object):
     BCM = 0
     BOARD = 0
     def __init__(self, busnum, address, num_gpios):
-        self.chip = Adafruit_MCP230XX(busnum, address, num_gpios)
+        self.chip = Adafruit_MCP230XX(address, num_gpios, busnum)
     def setmode(self, mode):
         # do nothing
         pass