This is the README file for USBasp.USBasp is a USB in-circuit programmer for Atmel AVR controllers. It simplyconsists of an ATMega8 and a couple of passive components. The programmeruses a firmware-only USB driver, no special USB controller is needed.Features:- Works under multiple platforms. Linux, Mac OS X and Windows are tested.- No special controllers or smd components are needed.- Programming speed is up to 5kBytes/sec.- SCK option to support targets with low clock speed (< 1,5MHz).- Planned: serial interface to target (e.g. for debugging).LICENSEThe project is built with AVR USB driver by Objective Development, which ispublished under a proprietary Open Source license. To conform with thislicense, USBasp is distributed under the same license conditions. See thefile "firmware/usbdrv/License.txt" for details. LIMITATIONSHardware:"circuit/usbasp_5V_circuit.pdf" shows a simple circuit. It doesn't meet thevoltage range on the data lines specified in USB 1.1. Also this circuit canonly be used for programming 5V target systems. For other systems a levelconverter is needed.Firmware:The firmware dosn't support USB Suspend Mode. A bidirectional serialinterface to slave exists in hardware but the firmware doesn't support it yet.USE PRECOMPILED VERSIONFirmware:Flash "bin/firmware/usbasp.xxxx-xx-xx.hex" to the ATMega8 with a workingprogrammer (e.g. with avrdude, uisp, ...). Set jumper J2 to activateUSBasp firmware update function.You have to change the fuse bits for external crystal, e.g. high byte = 0xc9and low byte = 0x9f.Windows:Start Windows and connect USBasp to the system. When Windows asks for adriver, choose "bin/win-driver". On Win2k and WinXP systems, Windows willwarn that the driver is is not 'digitally signed'. Ignore this message andcontinue with the installation.Now you can run the precompiled version of avrdude: change in command linemode to "bin/win-avrdude" and start the program. Consult the documentationof avrdude for details. Examples:1. Enter terminal mode with an AT90S2313 connected to the programmer:   avrdude -c usbasp -p at90s2313 -t2. Write main.hex to the flash of an ATmega8:   avrdude -c usbasp -p atmega8 -U flash:w:main.hexSetting jumpers:J1 Power target   Supply target with 5V (USB voltage). Be careful with this option, the   circuit isn't protected against short circuit!J2 Jumper for firmware upgrade (not self-upgradable)   Set this jumper for flashing the ATMega8 of USBasp with another working   programmer.J3 SCK option   If the target clock is lower than 1,5 MHz, you have to set this jumper.   Then SCK is scaled down from 375 kHz to about 8 kHz.BUILDING AND INSTALLING FROM SOURCE CODEFirmware:To compile the firmware1. install the GNU toolchain for AVR microcontrollers (avr-gcc, avr-libc),2. change directory to firmware/3. run "make"4. flash "main.hex" to the ATMega8. E.g. with uisp or avrdude (checkthe Makefile option "make avrdude"). To flash the firmware you haveto set jumper J2 and connect USBasp to a working programmer.You have to change the fuse bits for external crystal, e.g. high byte = 0xc9and low byte = 0x9f.Software (avrdude):An extension to avrdude (http://www.nongnu.org/avrdude/) was written.To compile the software:1. install libusb: http://libusb.sourceforge.net/2. get avrdude-5.0.tar.gz and extract it:   tar xvzf avrdude-5.0.tar.gz3. cp usbasp/software/usbasp.* avrdude-5.0/4. cd avrdude-5.05. apply the patch:   patch -p1 < ../usbasp/software/avrdude_usbasp.xxxx-xx-xx.patch6. configure to your environment:   ./bootstrap (I had to comment out the two if-blocks which verify the                installed versions of autoconf and automake)   ./configure7. compile and install it:   make   make installNotes on Windows (Cygwin):Download libusb-win32-device-bin-x.x.x.x.tar.gz fromhttp://libusb-win32.sourceforge.net/ and unpack it.-> copy lib/gcc/libusb.a to lib-path-> copy include/usb.h to include-pathcd avrdude./configure LDFLAGS="-static" --enable-versioned-doc=nomakeNotes on Darwin/MacOS X:after "./configure" I had to edit Makefile:change "avrdude_CPPFLAGS" to "AM_CPPFLAGS"(why is this needed only on mac? bug in configure.ac?)FILES IN THE DISTRIBUTIONReadme.txt ...................... The file you are currently readingfirmware ........................ Source code of the controller firmwarefirmware/usbdrv ................. AVR USB driver by Objective Developmentfirmware/usbdrv/License.txt ..... Public license for AVR USB driver and USBaspsoftware ........................ Source code of the host softwarecircuit ......................... Circuit diagram in PDFbin ............................. Precompiled programsbin/win-driver .................. Windows driverbin/win-avrdude ................. avrdude compiled for WindowsMORE INFORMATIONFor more information on USBasp and it's components please visit thefollowing URLs:USBasp .......................... http://www.fischl.de/usbasp/Firmware-only AVR USB driver .... http://www.obdev.at/products/avrusb/avrdude ......................... http://www.nongnu.org/avrdude/libusb .......................... http://libusb.sourceforge.net/libusb-win32 .................... http://libusb-win32.sourceforge.net/2005-11-14 Thomas Fischl <tfischl@gmx.de>http://www.fischl.de