Adafruit MCP23017 - i2c 16 input/output port expander

Add another 16 pins to your microcontroller using an MCP23017 port expander. The MCP23017 communicates using two I2C pins which can be shared with other I2C devices, offering 16 general-purpose pins in return. Each pin is configurable as an input, output, or input with a pull-up resistor.

An external pin offers interrupt capabilities, eliminating the need for continuous polling when inputs change. Compatible with 2.7-5.5V systems, it fits seamlessly into any 3.3V or 5V setup. The I/O pins can sink/source up to 20mA, suitable for driving LEDs, while additional power requirements can be met by pairing with a high-power MOSFET.

The DIP package facilitates easy integration into breadboards or perfboards. Achieve up to 8 unique I2C addresses by adjusting the ADDR0-2 pins, allowing up to 8 chips to coexist on the same I2C bus—expanding potential to 128 I/O pins. Proven reliability is demonstrated in applications such as our RGB LCD and Keypad shield.

Efficient set-up is ensured with an Arduino library featuring example code for setting pin states, reading and writing individual pins, and configuring pull-up resistors.