The Arduino Ethernet Shield connects your Arduino to the internet
in mere minutes. Just plug this module onto your Arduino board,
connect it to your network with an RJ45 cable (not included) and
follow a few simple instructions to start controlling your world
through the internet. As always with Arduino, every element of the
platform – hardware, software and documentation – is freely
available and open-source. This means you can learn exactly how
it's made and use its design as the starting point for your own
circuits. Hundreds of thousands of Arduino boards are already
fueling people’s creativity all over the world, everyday. Join us
now, Arduino is you!
* Requires and Arduino board (not included)
* Operating voltage 5V (supplied from the Arduino Board)
* Ethernet Controller: W5100 with internal 16K buffer
* Connection speed: 10/100Mb
* Connection with Arduino on SPI port
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. It 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 Arduino UNO board.
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
Arduino 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
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.
The current shield has a Power over Ethernet (PoE) module designed
to extract power from a conventional twisted pair Category 5
* IEEE802.3af compliant
* Low output ripple and noise (100mVpp)
* Input voltage range 36V to 57V
* Overload and short-circuit protection
* 9V Output
* High efficiency DC/DC converter: typ 75% @ 50% load
* 1500V isolation (input to output)
NB: the Power over Ethernet module is proprietary hardware not made
by Arduino, it is a third party accessory. For more information,
see the datasheet
The shield does not come with the PoE module built in, it is a
separate component that must be added on.
Arduino communicates with both the W5100 and SD card using the SPI
bus (through the ICSP header). This is on digital pins 11, 12, and
13 on the Duemilanove and pins 50, 51, and 52 on the Mega. On both
boards, pin 10 is used to select the W5100 and pin 4 for the SD
card. These pins cannot be used for general i/o. On the Mega, the
hardware SS pin, 53, is not used to select either the W5100 or the
SD card, but it must be kept as an output or the SPI interface
Note that because the W5100 and SD card share the SPI bus, only one
can be active at a time. If you are using both peripherals in your
program, this should be taken care of by the corresponding
libraries. If you're not using one of the peripherals in your
program, however, you'll need to explicitly deselect it. To do this
with the SD card, set pin 4 as an output and write a high to it.
For the W5100, set digital pin 10 as a high output.
The shield provides a standard RJ45 ethernet jack.
The reset button on the shield resets both the W5100 and the
The shield contains a number of informational LEDs:
* PWR: indicates that the board and shield are powered
* LINK: indicates the presence of a network link and flashes when
the shield transmits or receives data
* FULLD: indicates that the network connection is full duplex
* 100M: indicates the presence of a 100 Mb/s network connection (as
opposed to 10 Mb/s)
* RX: flashes when the shield receives data
* TX: flashes when the shield sends data
* COLL: flashes when network collisions are detected
The solder jumper marked "INT" can be connected to allow the
Arduino board to receive interrupt-driven notification of events
from the W5100, but this is not supported by the Ethernet library.
The jumper connects the INT pin of the W5100 to digital pin 2 of