PHP Resources for a Raspberry Pi
A list of resources for PHP programming on a Raspberry Pi
GPIO Libraries
All of these libraries support reading and writing values to the GPIO pins.
Supports registering callbacks for interrupt handling.
No support for interrupt handling, but does have support for a couple of devices (MCP3002 analog-to-digital converter, DS18B20 one wire temperature sensor).
Supports registering callbacks for interrupt handling. Uses React PHP and is event driven. Supports a range of MCP300X analog to digital converters.
Other Libraries
Library for controlling the Raspberry Pi camera module (raspicam). Supports still images and has a timelapse method. Uses a fluid interface.
Library for controlling the PiFace module. This is a port of the original python library and requires the PHP SPI extension.
Tutorials
SitePoint tutorial showing how to use PiPHP: GPIO to blink an LED a few times after detecting a push button interrupt.