The OSEPP I₂C Expansion Shield is an Arduino-Compatible daughter (extension) card. It provides easy interconnection with other I₂C devices, such as the OSEPP Sensor Modules family. As well, it integrates an I₂C switch that provides 4 additional isolated I₂C buses to enable the use without collisions of multiple I₂C devices with same I₂C addresses.

The main I₂C bus and each of the 4 additional I₂C bus are brought out to a robust latch-able 4-pin connector that allow easy plug and play functionality. Three selectable address bits for I₂C switch to allow stacking of up to eight Shields Supports boards with the Arduino Shield interface, such as (but not limited to): Duemilanove Uno Pro Bluetooth Mega/Mega 2560.