This is the README file for USBasp. USBasp is a USB in-circuit programmer for Atmel AVR controllers. It simply consists of an ATMega88 or an ATMega8 and a couple of passive components. The programmer uses 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). LICENSE USBasp is distributed under the terms and conditions of the GNU GPL version 2 (see "firmware/usbdrv/License.txt" for details). USBasp is built with V-USB driver by OBJECTIVE DEVELOPMENT GmbH. See "firmware/usbdrv/" for further information. LIMITATIONS Hardware: This package includes a circuit diagram. This circuit can only be used for programming 5V target systems. For other systems a level converter is needed. Firmware: The firmware dosn't support USB Suspend Mode. A bidirectional serial interface to slave exists in hardware but the firmware doesn't support it yet. USE PRECOMPILED VERSION Firmware: Flash "bin/firmware/usbasp.atmega88.xxxx-xx-xx.hex" or "bin/firmware/usbasp.atmega8.xxxx-xx-xx.hex" to the used controller with a working programmer (e.g. with avrdude, uisp, ...). Set jumper J2 to activate USBasp firmware update function. You have to change the fuse bits for external crystal (see "make fuses"). # TARGET=atmega8 HFUSE=0xc9 LFUSE=0xef # TARGET=atmega48 HFUSE=0xdd LFUSE=0xff # TARGET=atmega88 HFUSE=0xdd LFUSE=0xff Windows: Start Windows and connect USBasp to the system. When Windows asks for a driver, choose "bin/win-driver". On Win2k and WinXP systems, Windows will warn that the driver is is not 'digitally signed'. Ignore this message and continue with the installation. Now you can run avrdude. Examples: 1. Enter terminal mode with an AT90S2313 connected to the programmer: avrdude -c usbasp -p at90s2313 -t 2. Write main.hex to the flash of an ATmega8: avrdude -c usbasp -p atmega8 -U flash:w:main.hex Setting 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 ATMega(4)8 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 CODE Firmware: To compile the firmware 1. install the GNU toolchain for AVR microcontrollers (avr-gcc, avr-libc), 2. change directory to firmware/ 3. run "make main.hex" 4. flash "main.hex" to the ATMega(4)8. E.g. with uisp or avrdude (check the Makefile option "make flash"). To flash the firmware you have to set jumper J2 and connect USBasp to a working programmer. You have to change the fuse bits for external crystal, (check the Makefile option "make fuses"). Software (avrdude): AVRDUDE supports USBasp since version 5.2. 1. install libusb: http://libusb.sourceforge.net/ 2. get latest avrdude release: http://download.savannah.gnu.org/releases/avrdude/ 3. cd avrdude-X.X.X 5. configure to your environment: ./bootstrap (I had to comment out the two if-blocks which verify the installed versions of autoconf and automake) ./configure 6. compile and install it: make make install Notes on Windows (Cygwin): Download libusb-win32-device-bin-x.x.x.x.tar.gz from http://libusb-win32.sourceforge.net/ and unpack it. -> copy lib/gcc/libusb.a to lib-path -> copy include/usb.h to include-path cd avrdude ./configure LDFLAGS="-static" --enable-versioned-doc=no make Notes 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?) Notes on Linux: To use USBasp as non-root, you have to define some device rules. See bin/linux-nonroot for an example. FILES IN THE DISTRIBUTION Readme.txt ...................... The file you are currently reading firmware ........................ Source code of the controller firmware firmware/usbdrv ................. AVR USB driver by Objective Development firmware/usbdrv/License.txt ..... Public license for AVR USB driver and USBasp circuit ......................... Circuit diagram in PDF and EAGLE format bin ............................. Precompiled programs bin/win-driver .................. Windows driver bin/firmware .................... Precompiled firmware bin/linux-nonroot ............... Linux device rule file MORE INFORMATION For more information on USBasp and it's components please visit the following URLs: USBasp .......................... http://www.fischl.de/usbasp/ Firmware-only V-USB driver ...... http://www.obdev.at/products/vusb/ avrdude ......................... http://www.nongnu.org/avrdude/ libusb .......................... http://libusb.sourceforge.net/ libusb-win32 .................... http://libusb-win32.sourceforge.net/ 2011-05-28 Thomas Fischl <tfischl@gmx.de> http://www.fischl.de