To control your PiFace Digital from a browser, first login into your Raspberry Pi with your PiFace Digital connected, then open a Terminal and enter the command:
This will start a simple web server for you to access.
Open a browser on your Pi, or another computer on your network, and enter the following address into the address bar:
You can set the output port of PiFace Digital (the LEDs) by adding the following line to the end of the address:
So the full command will be:
0xaais a representation of the output port values in hexidecimal. The PiFace Digital sees this in the binary form
10101010 with a 1 representing an LED on, and a 0 representing an LED off.
0xff would have all the LEDs turned on, and
0x00 would have them all off.