PCF8574T IO Expansion Module – I2C Electronic Building Block

Expand your microcontroller's capabilities with the PCF8574T IO Expansion Module. This compact I2C-based electronic building block allows you to extend the number of digital input/output pins on your Arduino, Raspberry Pi, or other compatible microcontroller boards — all over a simple two-wire I2C bus. Perfect for hobbyists, students, and electronics enthusiasts looking to build smarter, more complex projects without the complexity.

Key Features

PCF8574T Chip: Industry-standard 8-bit I/O expander with I2C interface for easy integration
I2C Communication: Uses just two signal lines (SDA & SCL), saving precious pins on your main board
Configurable Address: On-board address jumpers allow up to 8 modules to be used on the same I2C bus simultaneously
Wide Compatibility: Works seamlessly with Arduino, Raspberry Pi, ESP8266, ESP32, STM32, and other popular development boards
Compact & Breadboard-Friendly: Small form factor fits neatly into any project enclosure or breadboard setup
Interrupt Output: Onboard interrupt pin (INT) signals the host processor when any input changes state — ideal for event-driven designs
Low Power Consumption: Efficient design makes it suitable for battery-powered and portable projects

Specifications

Chip: PCF8574T
Interface: I2C (up to 400 kHz)
I/O Pins: 8 bidirectional I/O ports
Operating Voltage: 2.5V – 6V
Addressable Range: 0x20 – 0x27 (8 unique addresses)
Interrupt Output: Active LOW open-drain
Form Factor: PCB module with standard pin header

Who Is This For?

Whether you're a beginner building your first electronics project or an experienced maker tackling a complex build, the PCF8574T IO Expansion Module is an affordable and reliable solution. It's great for controlling LED arrays, reading multiple button inputs, driving LCD displays (commonly used as an I2C LCD backpack), and much more.

Great Pairings for Your DIY Projects

Explore more components and creative building supplies in our store:

Learn more: OSHA on eye and face protection

Frequently Asked Questions

Q: What is the PCF8574T IO Expansion Module and what does it do?

A: The PCF8574T IO Expansion Module is an I2C-based digital I/O expander that adds 8 extra input/output pins to your microcontroller (such as Arduino or Raspberry Pi) using only two communication lines. It is ideal for projects that require more GPIO pins than your main board provides.

Q: Is the PCF8574T IO Expansion Module compatible with Arduino and Raspberry Pi?

A: Yes! The PCF8574T module is fully compatible with Arduino, Raspberry Pi, ESP8266, ESP32, STM32, and virtually any microcontroller that supports the I2C protocol. Simply connect SDA, SCL, VCC, and GND to get started.

Q: Can I use multiple PCF8574T modules in a single project?

A: Absolutely. Each module features configurable address jumpers that allow you to set a unique I2C address (0x20 through 0x27), meaning you can connect up to 8 PCF8574T modules on the same I2C bus — giving you up to 64 additional I/O pins in a single project.

Q: What projects can I build with this IO expansion module?

A: Common applications include controlling LED arrays, reading multiple button or switch inputs, driving I2C LCD displays, building keyboard matrices, home automation controllers, and any project where you need more digital I/O than your board natively provides.

Production & Packaging Notice

To maintain high stock availability and fast shipping times, our items are sourced from multiple verified manufacturing facilities. While the core quality, materials, and product specifications remain identical, you may notice slight variations in the packaging design, manufacturing origin, or the wording of the printed instructions.