Key Features:

• Expands GPIO using I2C interface (SDA/SCL)
• 8-bit quasi-bidirectional I/O pins
• Multiple modules can be used on the same I2C bus
• Built-in address selection pins (A0A2)
• Low power consumption design
• Compatible with 3.3V and 5V systems (depending on board variant)

Technical Details:

• IC: PCF8574
• Communication: I2C bus
• I/O Pins: 8 digital channels
• Default I2C address: Configurable via A0, A1, A2
• Operating voltage: Typically 2.5V 6V
• Interface pins: SDA, SCL, VCC, GND