

                                    CDC-2313


    This is the Readme file to firmware-only CDC driver for Atmel AVR
    microcontrollers. For more information please visit
    http://www.recursion.jp/avrcdc/


SUMMARY
=======
    The AVR-CDC performs the CDC (Communication Device Class) connection over
    low-speed USB. It provides the virtual RS-232C interface without installing
    dedicated driver. The AVR-CDC is originally developed by Osamu Tamura.
    Akira Kitazawa has significantly contributed to improve this software. 


SPECIFICATION
=============
    AVR-CDC with USART (ATtiny2313)
        speed: 9600bps
        datasize: 8
        parity: none
        stopbit: 1

    Some characters may be corrupted in continuous full-duplex transaction.

    Although the CDC is supported by Windows XP/2000, Mac OS X,9.1, and Linux,
    CDC on low-speed USB is not allowed by the USB standard. Use AVR-CDC at
    your own risk. 


USAGE
=====
    Build your circuit and write firmware (cdc2313.hex) into it.
    C1:104 means 0.1uF, R3:1K5 means 1.5K ohms.

    If the connection is unstable, add another diode after D2.
    Try other USB-Hub or PC.

    [Windows XP/2000]
    When you connect with a USB port first, a Driver Setup Dialog appears.
    Specify the folder in which "avrcdc.inf" exists, without searching
    automatically. Although it is warned that the driver is not certified,
    confirm it. It only loads Windows' built-in usbser.sys. Then, the Virtual
    COM port appears.
 

DEVELOPMENT
===========
    This driver has been developed on AVR Studio 4.13 SP2 and WinAVR 20071221.

    The code size of CDC-2313 is about 2KB, and 96B RAM is required at least.

    Fuses     FF DF-FF (ATtiny2313)


USING AVR-CDC FOR FREE
======================
    The AVR-CDC is published under an Open Source compliant license.
    See the file "License.txt" for details.

    You may use this driver in a form as it is. However, if you want to
    distribute a system with your vendor name, modify these files and recompile
    them;
        1. Vendor String in usbconfig.h
        2. COMPANY and MFGNAME strings in avrcdc.inf  



    Osamu Tamura @ Recursion Co., Ltd.
    http://www.recursion.jp/avrcdc/
    3 October 2007
    27 January 2008

