MCP23017-Arduino-Library

This is a library to control MCP23017 I2C modules (product page here). The library provides full control of the module using familiar functions like digitalWrite, digitalRead and pinMode, as well as other functionalities.

Note: The library does not support interrupts yet

Usage

Begin by including the library files and declaring an instance of the MCP23017 class.

#include <mcp23017.h>

#define MCP23017_ADDR (0x07) // I2C address of the module
MCP23017 mcp(MCP23017_ADDR);

Every instance of the MCP23017 class must be initialized after created. This will setup the module so it's compatible with the library, and initializes the Wire library if needed. To do this, just call the start() function inside setup() or loop()

After the instance is initialized, Arduino functions can be used to configure the additional I/O ports. These ports will be labeled GPAn for ports in the A bank, and GPBn for ports in the B bank (0 <= n < 8). Below you'll find a basic example, and there are more examples in the examples folder.

// Blink a LED

#include <mcp23017.h>

#define MCP_ADDR (0)

MCP23017 mcp(MCP_ADDR);

void setup(void)
{
    mcp.start();
    mcp.pinMode(GPB7, OUTPUT);
}

void loop(void)
{
    mcp.digitalWrite(GPB7, HIGH);
    delay(250);
    mcp.digitalWrite(GPB7, LOW);
    delay(250);
}