Arduino Ethernet Shield W5100

The Arduino Ethernet Shield allows an Arduino board to connect to the internet. It is based on the Wiznet W5100 ethernet chip. The Wiznet W5100 provides a network (IP) stack capable of both TCP and UDP. The Ethernet W5100 Shield Network Expansion Board w/ Micro SD Card Slot supports up to four simultaneous socket connections.

Use the Ethernet  library to write sketches which connect to the internet using the shield . 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.

The most recent revision of the board exposes the 1.0 pinout on rev 3 of the Ardunio uno  board. This Ethernet Shield connects the UNO R3 board to the internet in mere minutes. Just plug this module onto your Arduino board, connect it to your network with an RJ45  (not included) and follow a few simple instructions to start controlling your world through the internet. allows you to connect your Ardunio uno 328  or mega 2650 1280 to a network or the internet AND retrieve or store files on a Micro SD Card!

The Ethernet Shield has a standard RJ-45 connection, with an integrated line transformer and Power over Ethernet enabled. There is an onboard micro-SD card slot, which can be used to store files for serving over the network. It is compatible with the Uno and Mega (using the Ethernet library). The onboard microSD card reader is accessible through the SD Library. When working with this library, SS is on Pin 4. The original revision of the shield contained a full-size SD card slot; this is not supported.

The shield also includes a reset controller, to ensure that the W5100 Ethernet module is properly reset on power-up. Previous revisions of the shield were not compatible with the Mega and need to be manually reset after power-up.