Hardware and software requirements
On the hardware side, you will of course need the Arduino Ethernet shield and an Arduino board such as the Arduino Uno.
You will also need a sensor to measure some data. As this book is about how to use the Ethernet shield and not how to measure from sensors, you can actually use a sensor of your choice.
I picked a DHT11 sensor, which is a digital temperature and humidity sensor. I chose this sensor as it is a very cheap sensor and easy to interface with Arduino. Along with the DHT11 sensor, you will also need a 4.7k ohm resistor.
You will also need a breadboard and some jumper wires to make the connections between the sensor and the Ethernet shield.
On the software side, the first thing you will need is the library to interface with the sensor you chose before. As I chose a DHT11 sensor for this project, you will need to download and install the DHT library from https://github.com/adafruit/DHT-sensor-library.
To install an Arduino library, simply unzip the...
