Adafruit GPIO Expander Bonnet for Raspberry Pi Easily add SIXTEEN additional I/O over I2C! by Liz Clark published March 06, 2019, last edited August 15, 2025 last major update November 02, 2023 posted in Adafruit Products Raspberry Pi CircuitPython Breakout Boards STEMMA Save New Favorite × Please sign in to include this guide in your list of favorites. You will be redirected back to this guide once you sign in, and can then save this guide as one of your favorites. Link Note Download Overview Pinouts Python Usage Python Docs Downloads Single page Feedback? Corrections? Text View Guide Products view all Primary Adafruit GPIO Expander Bonnet - 16 Additional I/O over I2C $9.95 Add to Cart View product details 6 Beginner Product guide Downloads Files MCP23017 GPIO Expander Datasheet Adafruit GPIO Expander Bonnet EagleCAD files on GitHub Rev B Fritzing object in our Fritzing repo Rev C Fritzing object in our Fritzing repo Rev C 3D model on GitHub Schematics and Fab Print Rev C dimensions are in inches Rev B Page last edited August 15, 2025 Text editor powered by tinymce. Python Usage