The Arduino Ethernet Shield allows an Arduino board to connect to the
Internet. It is based on the Wiznet W5100 Ethernet chip. The W5100 provides a
network (IP) stack capable of both TCP and UDP operation. It supports up to four
simultaneous socket connections. The Ethernet shield connects 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 pins 10, 11, 12, & 13 (SPI) to
communicate with the Ethernet shield. These pins cannot be used for general
I/O Power-over-Ethernet enabled RJ-45 Ethernet socket (current Rev 3
product) Supplied with or without PoE module (current Rev 3 product) Reset
button on the shield resets both the W5100 and the Arduino board Seven status
LEDs SD card slot (MicroSD on current Rev 3 product)
