"Objective Development Software GmbH" allows using their USB VID/PID under certain condition, including commercial purpose. AVR-CDC's firmware is opened with GPL2 license. Please be careful to follow both the V-USB and the AVR-CDC's license agreements.


This is an INF file and the patch driver for Windows 2000/XP/Vista/7. The instruction and the source code is included.
No driver installation is required on Mac OS, Linux 2.4, and Linux 2.6.31-.    (40 KB,  2010-03-21 updated)

These are the performance evaluation of AVR-CDC.  (2006-08-28)

Summary (PDF 9KB),    CDC-mega (PDF 18KB),    CDC-tiny (PDF 15KB)


Source code and HEX files.   (343 KB)
cdc232.2011-06-24.tgz   (267 KB)


Source code and HEX files.   (316 KB)
cdcio.2009-07-15.tgz   (259 KB)

These are the sample programs (C, C++, C#, VB) for CDC-IO ATmega8/48/88 version.   (341 KB)
iosample.2009-07-15.tgz   (298 KB)


Source code and HEX files.   (349 KB)
cdcspi.2010-02-06.tgz   (292 KB)

These are the sample programs (spitest, spiprog) for CDC-SPI.   (81 KB)
spisample.2010-02-08.tgz   (79 KB)


LibUSB is an open-source project of the general purpose USB interface driver. You can control AVR-CDC device directly without loading "usbser.sys". This is the patch to enable low-speed bulk transfer on Vista. This may be useful for all "low-speed bulk" devices. Download the original LibUSB and add this portion. Rebuild the "libusb0.sys" with this replacement.  "bulk.c" is a CDC-IO sample to transfer data.