DFRobot DFRduino - DFRobot DFR0125, This version, V2.1, of the DFRobot DFRduino Ethernet Shield is not only compatible with Mega 1280 and 2560, but also provides a Micro SD card slot for reading/writing. DFRduino Ethernet Shield V2.1 is fully compatible with Arduino Ethernet Shield - with the official ethernet library, you can do exactly the same thing as the original one, but at a more affordable price.This Ethernet Shield provides an Arduino controller board with internet access. It is based on the Wiznet W5100 ethernet chip. The Wiznet W5100 provides a network (IP) stack capable of both TCP and UDP. It supports up to four simultaneous socket connections. You can use the Ethernet library to write sketches which connect to the internet using the shield. You can connect the Ethernet Shield to an Arduino board using long wire-wrap headers which extend through the shield. This keeps the pin layout intact and allows another shield to be stacked on top.Arduino uses digital pins 10, 11, 12,