The Arduino WiFi Shield can also be configured and programmed as a web server to serve client requests similar to the Arduino Ethernet shield. In the next step, we will be making a simple web server to send Wi-Fi signal strength over the Internet to a client. This requires that the WiFi shield has 1.1.0 firmware to work. The default factory loaded version 1.0.0 will not work. (See the Firmware upgrading section.)
To read the signal strength over Wi-Fi:
Chapter 2sample code folder.