1. Multi-Channel Expansion: The module offers multiple configurable input/output channels, allowing you to expand a single I/O pin into many. 2. Digital Input/Output: This expansion board supports both digital input and output, enabling you to input external signals into a microcontroller or output signals from the microcontroller to external devices. 3. Low Power Consumption: Designed with low power consumption in mind, this muti-channel expansion board minimizes power usage during operation, making it ideal for applications requiring long-term use and extended battery life. 4. Programmable Features: The expansion module is highly programmable, allowing you to set the working mode, polarity, and current drive capability of input/output channels through configuration registers. 5. High Reliability and Stability: Built with premium components and reliable circuit design, this expansion module ensures high reliability and stability for your projects. Type: Module Condition: The operating voltage of is 1.65V to 5.5V, J1-J2 single row pin spacing: 800mil (2.54mmx8=20.32mm).Suitable for access to breadboards. All 16 IO ports have LED indicators. The LED is designed with a common anode and uses a 2k resistor to limit the current; when the output of the IO port is logic 0, the LED lights up. Specification: PCA9555A Colour:Green Material:ABS Package Contents: 1 x Expansion Board Module