Waveshare AW9523B IO Expansion Board. This versatile module provides a quick and easy way to add up to 16 additional GPIO pins—each configurable as either a general-purpose input/output or a constant-current LED driver. By interfacing over the I²C bus, you can effortlessly integrate multiple expansion boards to support large-scale designs that require an abundance of I/O or custom lighting control.

Key Features

1. 16 Configurable I/O Pins

   • The AW9523B chip features 16 channels that can function as standard GPIO pins or operate in LED driver mode. This flexibility allows you to mix and match general-purpose input/outputs with built-in constant-current sources for LEDs.

2. I²C Interface & Address Options

   • Communicate with the board over a standard I²C bus. With multiple address configuration options, you can integrate up to four AW9523B boards (or more, depending on address settings) on the same bus, expanding I/O without pin conflicts.

3. Constant-Current LED Driving

   • In LED driver mode, each channel includes current-limiting capabilities, eliminating the need for external resistors. This setup ensures stable and uniform LED brightness across all channels, whether for status indicators or decorative lighting.

4. Wide Voltage Range

   • Operates over a broad supply voltage range (2.4V to 5.5V), allowing easy power integration with most common development boards and microcontrollers, including Arduino, Raspberry Pi, STM32, ESP32, and more.

5. Qwiic / STEMMA QT Compatibility

   • Features a built-in Qwiic (or compatible) connector for simplified, solder-free wiring. Ideal for makers and professionals looking to reduce setup complexity and avoid messy cables.

6. Onboard Configuration Jumpers

   • Convenient jumpers let you quickly set I²C address or operating modes. Adjust the hardware configuration without needing external switches or re-soldering connections.

7. Compact & Mountable Design

   • With a small PCB footprint and mounting holes, the board can be easily embedded into enclosures or neatly arranged within your existing setup.

How It Works

1. Power & I²C Connections: Supply 3.3V or 5V (depending on your system) to the board and link the I²C SDA/SCL lines from your microcontroller.

2. Address Configuration: Use the onboard jumpers to select an I²C address that doesn’t conflict with other devices on the same bus.

3. Pin Mode Setting: Configure each of the 16 channels via software registers as GPIO (input or output) or enable the LED driver functionality.

4. Programming & Control: Through your microcontroller’s I²C library or custom code, read pin states, toggle outputs, or drive LEDs with set current levels—unlocking rich functionality for interactive projects.

Use Cases

• LED Indicators & Lighting: Drive multiple status LEDs, decorative lights, or multi-segment displays, benefiting from integrated constant-current sinks.

• Button & Sensor Arrays: Expand input capability by connecting pushbuttons, switches, or sensors without consuming precious microcontroller pins.

• Motor & Relay Control: Manage additional relays or transistors for power or motor control in larger systems requiring many control lines.

• Prototyping & Education: Ideal in classroom or maker environments where quick I/O expansion is needed to test various sensors, actuators, or displays simultaneously.

Technical Specifications

(For exact details, refer to the official Waveshare documentation.)

• Chipset: AW9523B

• Interface: I²C (SDA/SCL)

• Number of I/O Pins: 16 (each configurable as GPIO or LED driver)

• Operating Voltage: 2.4V ~ 5.5V

• Current per Channel (LED Driver): Up to 37.5mA (configured via registers and internal constraints)

• I²C Address Range: Multiple hardware address settings for easy daisy-chaining

• Dimensions: Compact PCB size with mounting holes (check datasheet for exact measurements)

Why Choose the Waveshare AW9523B IO Expansion Board?

For projects that demand numerous I/O lines or involve LED-rich designs, the Waveshare AW9523B IO Expansion Board provides an elegant, all-in-one solution. Its flexible configuration of GPIO or LED driver mode helps streamline hardware layouts, reducing external component requirements and saving development time. Coupled with easy I²C connectivity and Qwiic compatibility, this module ensures your design remains clean, scalable, and efficient—whether you’re a hobbyist, educator, or professional engineer.