Base shield is designed for the Arduino and its compatible interface development board. Make all the I/O pins on the Arduino leads into standard 4-pin interface form. Through which users can easily make Electronic module and Arduino link without considering the actual location of the corresponding pin. Considering the different Electronic module interface communication mode Base shield has digital analog I2C SPI compatible with different methods of communication interface. All by the side of the seat has clear instructions even a beginner don't worry connect wrong. Compatible with the Arduino and other development board has the same form. Compatible with all Electronic module more I2C interface convenient links. Clear indicator light work. Concise and complete plate printing information.