D2XX is Future Technology Devices International (FTDI) proprietary interface for easy communication with its FTxxxx devices like FT232R (USB<->UART converter) or FT4222H (High/Full Speed USB2.0-to-Quad SPI/I2C device controller). The D2XX interface provides special functions that are not available in standard operating system COM port APIs, such as setting the device into a different mode or writing data into the device EEPROM.

Future Technology Devices International ( ftdi) provides two alternative software interfaces for its range of USB UART and USB FIFO ICs. One interface provides a Virtual COM Port (VCP) (kind of serial-port) which appears to the system as a COM port. The second interface, D2XX, is provided via a proprietary driver (like FTD2XX.DLL for Windows or d2xx.jar for Android/Java). The D2XX API is common across several operating systems supported by FTDI, namely Windows, Windows CE, Linux, Mac OS X and Android.

D2XX drivers allow direct access to the USB device. Application software can access the USB device through a series of API function calls. The functions available are listed in the D2XX Programmer's Guide.

Useful links:

Official web page

Installation Guides

D2XX Android Java Library

Java D2xx for Android API User Manual

Android D2XX Example Source code