Compatibility Level: Changes in the state of an input port can generate an interrupt output (INT). Built-in level conversion circuit, compatible with 3.3V/5V working levels. Supports 4 Expansion Modules: The I2C communication address can be set. Shorting the AO and A1 solder points can modify the communication address, supporting the use of 4 expansion modules. I2C Interface Control: With I2C interface control, only 2 signal wires are needed to expand 16 I/O ports. Current Control: The expansion module supports 16-channel common anode constant current ED driving, 256-level linear dimming, and current control. Two Interface Types: The I2C interface expansion board provides two interface types: PH2.0 terminal and pad, and supports parallel connection of multiple I2C modules. Item Type: IO Expansion Board Material: PCB Working Voltage: 2.4-5.5V Working Temperature: -40 to 80℃ Control Interface: I2C Number of Expanded I/O Ports: 16 VCC: Positive power supply, can be connected to a 3.3V/5V power supply GND: Power ground SDA: I2C data line SCL: I2C clock line INT: Interrupt output RST: Hardware reset Size: Approx. 38 x 23mm / 1.5 x 0.9in 1 x IO Expansion Board 1 x Dupont Wire