Testing the Ethernet Shield

The Ethernet shield is an essential part of the rest of the gadgets in this book. So let’s test it to be sure it works before building anything with it.


  1. Arduino
  2. Ethernet shield


Step 1 Attach the Ethernet shield to Arduino.

Step 2 Plug the shield into your Internet router.

Step 3 Find the sketch “Web Server” in the Arduino IDE, under File | Examples | Ethernet | WebServer, or on EMWA GitHub repository | chapter-6 | WebServer. Load it onto Arduino.


Be certain to insert the MAC address of your Ethernet shield and the IP address you wish to give to your Arduino into the following sketch. A good rule of thumb is to add 20 to the IP address of your router, which should ensure that your Arduino doesn’t have the same address as other devices on your local network (as long as you have no more than 20 devices on the network.) That is, if your router is at IP address, make your Arduino’s IP address

Step 4 When you’ve uploaded the sketch to Arduino, and the sketch is running, go to your computer, open up your Internet browser (Chrome, Safari, Firefox, Internet Explorer, or whichever), and enter your Arduino’s IP address into the address bar.

You should see a very simple little web page, resembling what the Web looked like in 1994. Congratulations! Your Arduino is now a web server on the Internet.

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