public MCP23017(byte address = 0x20)
{
i2cDevice = new NetduinoI2CDevice(address);
// set the defaults
i2cDevice.WriteRegister((byte)Command.MCP23017_IODIRA, 0xff);
i2cDevice.WriteRegister((byte)Command.MCP23017_IODIRB, 0xff);
}
public MCP23017(byte address = 0x20)
{
i2cDevice = new NetduinoI2CDevice(address);
// set the defaults
i2cDevice.WriteRegister((byte)Command.MCP23017_IODIRA, 0xff);
i2cDevice.WriteRegister((byte)Command.MCP23017_IODIRB, 0xff);
//The below were added in order to read the interrupt from the chip.
//i2cDevice configuration register
// mirror interrupts, disable sequential mode
i2cDevice.WriteRegister((byte)Command.MCP23017_IOCONA, 0x60); // 0b01100000 (binary) = ox60 (hexadecimal)
// enable pull-up on switches
i2cDevice.WriteRegister((byte)Command.MCP23017_GPPUA, 0xff); // pull-up resistor for switch - both ports
// invert polarity
i2cDevice.WriteRegister((byte)Command.MCP23017_IPOLA, 0xff); // invert polarity of signal - both ports
// enable all interrupts. This one is what needs to be enabled for the data to flow to the pin...
i2cDevice.WriteRegister((byte)Command.MCP23017_GPINTENA, 0xff);
//i2cDevice.WriteRegister((byte)0x12, 0xff);
}