In this example, you will use your Ethernet Shield and your Arduino or Genuino board to make a chat client.
The Ethernet shield allows you to connect a WizNet Ethernet controller to the Arduino or Genuino boards via the SPI bus. It uses pins 10, 11, 12, and 13 for the SPI connection to the WizNet. Later models of the Ethernet shield also have an SD Card on board. Digital pin 4 is used to control the slave select pin on the SD card.
The shield should be connected to a network with an ethernet cable. You will need to change the network settings in the program to correspond to your network.
In the above image, the Arduino or Genuino board would be stacked below the Ethernet shield.
Last revision 2015/08/13 by SM