Overview: This product adopts I2C interface to realize 16 I/O port expansion. Support for Raspberry Pi Zero/Zero W/Zero WH/2B/3B/3B+/4B etc models as well as Ardui and STM32. We provide C and Python demo codes for the Raspberry Pi, as well as Ardui and STM32 demo codes, that can implement input testing, output testing, and interrupt testing. Specifications: Size: 45mm(Length)*25mm(width) Control Chip: MCP23017 Signal interface: I2C Supply voltage: 3.3V/5V Expansion I/O: 16 Interrupt pin: INTA?INTB Interface definition: VCC: Power supply positive(3.3V/5V) GND: Power supply ground SDA: I2C data line SCL: I2C clock line INTA: PA port interrupt pin INTB: PB port interrupt pin Package contents: 1.SG-IO-E017×1 2.PH2.0 6PIN connecting cable×1