SmartElex SX1509 16-Channel I/O Expander Breakout Board with I2C Interface

The SmartElex SX1509 16-Channel I/O Expander is the perfect solution when you’re running out of GPIO pins on your microcontroller. Using a simple I2C interface, it allows you to expand your project with 16 additional digital I/O pins.

Each pin can be configured as input or output, letting you connect sensors, LEDs, or other devices with ease.Beyond basic expansion, this SX1509 breakout board comes packed with smart features like built-in PWM control for LED dimming, blinking, and breathing effects.

It even includes a keypad engine that can handle up to 64 buttons in an 8×8 matrix, making it ideal for interactive projects, embedded systems, and robotics applications. With voltage flexibility and level-shifting capability, it’s a must-have for anyone working with Arduino or other I/O-limited microcontrollers.

Features:

• 16 configurable digital I/O channels with bi-directional support
• I2C-compatible interface for easy microcontroller communication
• 5.5V tolerant I/Os with up to 15mA sink capability
• Built-in PWM generator for LED brightness control and effects
• Integrated keypad scanning engine supporting up to 8×8 (64 keys)
• Works as a level shifter between 1.2V and 3.6V banks
• Compact breakout design for quick prototyping