It’s an Arduino shield that adds a Linux SoC, WiFi, Ethernet, and USB Host to any Arduino board from the Uno, to the Duemilanove ... All the hardware files are available on the Yun shield ...

Microcontroller demo boards such as the Arduino UNO are ubiquitous on Hackaday as ... position due to a custom jig which means a standard shield will fit right into place. The Arduino started ...