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Arduino among others has a really nice feature… The bootloader. Once you burn it on the chip you can upload your code without the need of an external programmer.

I have started using it for my AVR projects but i came across on some issues so i compiled a COMPLETE list of what you need to do it, in order not to search again for the obvious…

Programmer used AVR910 (or compatible) with avrdude. In the avrdude commands I assume that the
programmer is AVR910, COM port=COM3 and baud rate=115200. Adjust to your programmer.

Have in mind that you might use also -x devcode=0×35 for AVR910

ATMEGA8

The default fuses of ATMega8 are (pdf and locally tested):
High Fuse:      0xd9
Low Fuse:       0xe1
Lock:           0x3f

Programming the bootloader. Chip erase (-e maybe needed in some cases)

• Unlock the bootloader (TEST: try with -e)

avrdude -c avr910 -P com3 -b 115200 -p atmega8 -U lock:w:0xff:m
(fails with avrdude: verification error, first mismatch at byte 0×0000 0xff != 0x3f)

• Program the fuses

avrdude -c avr910 -P com3 -b 115200 -p atmega8 -U hfuse:w:0xca:m -U lfuse:w:0xdf:m

• Burn the bootloader (TEST: try with -D disable auto erase)

avrdude -c avr910 -P com3 -b 115200 -p atmega8 -U flash:w:ATmegaBOOT.hex

• Lock the bootloader

avrdude -c avr910 -P com3 -b 115200 -p atmega8 -U lock:w:0xcf:m
(fails with avrdude: verification error, first mismatch at byte 0×0000 0xcf != 0x0f)

But it works….

ATMEGA168

The default fuses of ATMega168 are (pdf and locally tested):
High Fuse:      0xd9
Low Fuse:       0xe1
Lock:           0x3f

Programming the bootloader. Chip erase (-e maybe needed in some cases)

• Unlock the bootloader

avrdude -c avr910 -P com3 -b 115200 -p atmega168 -U lock:w:0x3f:m

• Program the fuses

avrdude -c avr910 -P com3 -b 115200 -p atmega168 -U hfuse:w:0xdd:m -U lfuse:w:0xff:m -U efuse:w:0x00:m

• Burn the bootloader

avrdude -c avr910 -P com3 -b 115200 -p atmega168 -U flash:w:ATmegaBOOT_168_ng.hex

• Lock the bootloader

avrdude -c avr910 -P com3 -b 115200 -p atmega168 -U lock:w:0x0f:m

And now the good part:

Once you burn the bootloader to a chip you can use this excellent program to upload any hex file to your ATmega with Arduino uploader

References

• http://www.arduino.cc/en/Tutorial/Bootloader
• http://arduino.cc/en/Hacking/Bootloader
• http://arduino.cc/en/Hacking/Bootloader?from=Main.Bootloader
• (settings based on http://arduino.cc/en/Hacking/Bootloader?from=Main.Bootloader 09/01/2009)

Updated: April 2012