TOOGOO(R) Ethernet Shield W5100 Network Expansion Board for Arduino UNO R3 Mega 2560 1280 The most recent revision of the board exposes the 1.0 pinout on rev 3 of the Arduino UNO board for further development. The Arduino ethernet shield allows an Arduino board to connect to the internet. It is based on the Wiznet W5100 ethernet chip (datasheet). The Wiznet W5100 provides a network (IP) stack capable of both TCP and UDP. Color: As shown