W5100 Ethernet Network Shield Expansion Board for Arduino 


The Arduino Ethernet Shield allows an Arduino board to connect to the internet. It is based on the Wiznet W5100ethernet 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 that 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.

Features of W5100 Ethernet Shield

  • 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 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 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.
  • The current shield has a Power over Ethernet (PoE) module designed to extract power from a conventional twisted pair Category 5 Ethernet cable.
  • IEEE802.3af compliant
  • Overload and short-circuit protection

Pinout of W5100 Ethernet Shield

W5100-Ethernet Network Shield-Pinout
Pin NamePin Description
D11, D12, D13 pin Arduino communication is done using SPI bus through ICSP header so pin numbers on classic Arduino models are used for this purpose
D 50, and D 52 on Arduino Mega serve the same purpose.
D 10 pinused and it’s a general purpose input output pin
D 4 pin general purpose input output pin but it is used for SD cards.
D 2 pinis named as INT on Arduino board and is connected with INT pin of W5100
D 53 is although SPI pin but it cannot be used to select either W5100 or SD card it should be kept as an output or our SPI interface will not work.

Specifications of W5100 Ethernet Shield

Low output ripple and noise(100mVpp)
Input voltage range36V to 57V
High-efficiency DC/DC converterTyp 75% @ 50% load
isolation (input to output)1500V

Datasheet W5100 Ethernet Shield

Download the W5100 Ethernet Shield Datasheet from the link given below.