PCF8574T I2C I/O Extension Board

The PCF8574T I2C I/O Extension Board is a compact and versatile module based on the PCF8574T 8-bit I/O expander IC. It allows a microcontroller to expand its digital input/output pins using the I2C communication protocol, requiring only two data lines. This board is ideal for applications where GPIO pins are limited but additional digital inputs or outputs are needed.

Technical Specifications:

• IC Used: PCF8574T
• Interface: I2C (SDA, SCL)
• Operating Voltage: 2.5 V to 6 V (typically 3.3 V or 5 V)
• Number of I/O Pins: 8 (P0–P7)
• I2C Address Range: 0x20 to 0x27 (configurable via address jumpers)
• I/O Type: Quasi-bidirectional
• Onboard Pull-up Resistors for I2C lines
• Standard 2.54 mm pin headers for easy connection
• Compact PCB form factor

Features:

• Expands microcontroller GPIO using only two I2C pins
• Individually configurable I/O pins as input or output
• Multiple boards can be connected on the same I2C bus
• Supports both 3.3 V and 5 V logic systems
• Simple wiring and easy integration with Arduino, ESP32, Raspberry Pi, and similar platforms
• Low power consumption

Applications:

• GPIO expansion for Arduino, ESP32, Raspberry Pi, and other microcontrollers
• Driving LEDs, relays, buzzers, and digital displays
• Reading switches, buttons, and digital sensors
• Home automation and IoT projects
• Prototyping and educational electronics projects
• Industrial control systems where I/O expansion is required