arduino MCP23017-E/SPI2CInterfaceIO Expander 16bit DIP-28 Electronic Components Electronic Hobby Kit

MCP23017-E/SP 16-Bit I/O Expander With Serial Interface The MCP23017 Device provides 16-Bit, general purpose parallel I/O expansion for I2C bus applications.The 16-Bit I/O port functionality consist of two 8-bit ports (PORTA and PORTB). There are two interrupt pins INTA and INTB, That can be associated with their respective ports, or can be OR'ed together so that both pins will activate if either port causes an interrupt. The interrupt output can be configured to activate under two conditions (mutually exclusive) : 1. When any input state differs from its corresponding input Port register state. This is used to indicate to the system master that an input state has changed. 2. When an input state differs from a preconfigured register value (DEFVAL register).