Adafruit MCP23017 I2C GPIO Expander Breakout - STEMMA QT / Qwiic

The Adafruit MCP23017 I2C GPIO Expander Breakout is a plug-and-play version of the popular MCP23017 chip, designed for easy integration with STEMMA QT and Qwiic ecosystems. Featuring 16 GPIO pins with matching ground pad, it operates at 3V or 5V logic and power. Each GPIO can output up to 25mA suitable for driving LEDs or be configured as an input with optional pullups. Two configurable IRQ pins support interrupt-driven operation, eliminating the need for constant I2C bus polling.

This breakout supports up to 8 devices on the same I2C bus, providing a total of 128 GPIO pins. It includes two sticks of header for breadboard compatibility and features the STEMMA QT form factor for seamless I2C connection with various sensors and accessories.

• 16 GPIO pins with 25mA output drive capability
• Compatible with 3V and 5V logic levels
• Interrupt support with two IRQ pins
• Three address pins allow up to 8 devices on one I2C bus
• STEMMA QT / Qwiic connectors for easy plug-and-play
• Includes dual 2x16 pin headers
• Robust Arduino and CircuitPython libraries and examples available
• Product dimensions: 43.0mm x 18.0mm x 5.0mm (1.7" x 0.7" x 0.2")

Note: The PORT A pins (A0-A7) are digital I/O only, not analog inputs. STEMMA QT cable not included, available separately.