2PCS PCF8575 IO Expander Board - I2C To 16IO Module For Arduino UNO R3

About This Product

Arduino enthusiasts and electronics hobbyists, these PCF8575 IO expander boards are absolute game-changers when you run out of pins on your microcontroller! Each board gives you 16 additional input/output pins while only using two I2C pins on your Arduino - that's seriously efficient. The I2C interface means you can daisy-chain multiple boards to expand even further if needed. The default I2C address is 0x20, but you can modify it by soldering the A1 and A2 selection pads if you need multiple boards on the same bus. The working voltage range of 2.5-5.5VDC makes these compatible with most Arduino boards and other microcontrollers. There's even a 3.3V level converter circuit on board - if you don't solder the VCC-VDD pad, the PCF8575 operates at 3.3V, but if you do solder it, the level matches your VCC. Each of the 16 pins is individually addressable and configurable as either input or output, giving you incredible flexibility for your projects. The open-drain interrupt output pin is super useful for input change interrupts. You get two boards in the pack, which is perfect for more complex projects or having a spare. These are ideal for controlling relays, buzzers, buttons, LEDs, or any simple components when you've exhausted your Arduino's built-in pins. The Open-Smart library support makes programming straightforward, and the compact size means they won't take up much space on your breadboard or in your project enclosure. Whether you're building a home automation system, robotics project, or any electronics creation that needs more IO than your Arduino provides, these expander boards deliver reliable performance at an affordable price. They're one of those components that instantly make your projects more capable and professional.