Do you find yourself wishing that you had just a few more GPIO pins? What if you only need that one more pin? You could add another microcontroller to your project but that increases cost and complexity. Instead, you can use the Qwiic GPIO to add eight new pins to your Qwiic project!

The Sparkfun Qwiic GPIO is an I²C device based around the TCA9534 I/O Expander IC from Texas Instruments. The board adds an additional eight IO pins which you can read and write just like any other digital pin on your controller. The details of the I²C interface have been taken care of in an Arduino library so you can call functions similar to Arduino's pinMode and digitalWrite, allowing you to focus on your creation!

The TCA9534's pins are broken out to easy-to-use latch terminals; never screw another wire into place! The terminals are relatively roomy themselves, so feel free to latch multiple wires into a ground or power terminal. With three customizable address jumpers, you can have up to eight Qwiic GPIO boards to be connected on a single bus allowing upwards of 64 additional GPIO pins! The default I²C is 0x27 and can be changed by adjusting the jumpers on the back of the board.

The SparkFun Qwiic connect system is an ecosystem of I²C sensors, actuators, shields and cables that make prototyping faster and less prone to error. All Qwiic-enabled boards use a common 1mm pitch, 4-pin JST connector. This reduces the amount of required PCB space, and polarized connections mean you can’t hook it up wrong.

• Eight Configurable GPIO Pins Available
• I²C Address: 0x27 (Default)
  • Hardware address pins allow up to eight boards on a single bus
• Input Polarity Inversion Register
• Control each I/O pin individually or all at once
• Open-Drain Active-Low Interrupt Output
• 2x Qwiic Connectors
• Dimensions: 2.40in x 1.50in (60.96mm x 38.10mm)

• Schematic
• Eagle Files
• Hookup Guide
• Board Dimensions
• Datasheet (TCA9534)
• Qwiic Resource Page
• Arduino Library
• Python Package
• GitHub Hardware Repo