Communication Interfaces, Operating Systems, and Drivers
The three most common communications interfaces for touch controllers are SPI, I2C, and USB. SPI and I2C are hardware level only specs. USB defines the hardware and software interface. Most USB controllers support the standard HID digitizer device class. Some also support an absolute mode mouse option. Operating system support for multi-touch digitizers varies based on the OS and the version. Some controllers and OSes support a feature called Wake on Touch which can be difficult to configure.