PCF8574 I2C IO Expander Module for Arduino

PCF8574 I2C I/O Expander Module

Running out of GPIO pins on your Arduino or microcontroller? The PCF8574 I2C I/O Expander Module gives you 8 additional digital I/O pins using just 2 wires (SDA + SCL). With configurable I2C addresses via onboard jumpers, you can chain up to 8 modules on a single bus — that's 64 extra pins from one I2C port!

Key Features

• PCF8574 IC — 8-bit I2C I/O expander
• I2C interface: only 2 wires needed (SDA, SCL)
• Configurable I2C address via A0 jumper (up to 8 modules on one bus)
• Dual connector options: 4-pin male header (left) and screw terminal (right)
• Yellow 8-pin GPIO header for easy access to all 8 I/O pins
• Operating voltage: 2.5V – 6V (3.3V and 5V compatible)
• Onboard decoupling capacitor for stable operation

Specifications

• IC: PCF8574
• Interface: I2C
• I2C Address: 0x20 – 0x27 (configurable via A0–A2 jumpers)
• I/O Pins: 8 (P0–P7)
• Supply Voltage: 2.5V – 6V
• Compatible with: Arduino, ESP32, Raspberry Pi, STM32

Applications

• GPIO expansion for Arduino and ESP32 projects
• LCD backpack / I2C LCD interface
• Keypad and button matrix scanning
• LED and relay control
• Industrial I/O expansion