ATmega8515 Fuse Bits

[neo644]

Hello, I'm using an Atmel ATmega8515 micro controler, and i have a
problem writing the fuse bits. I did write them, but i think i did it
wrong (I'm using an external crystal oscilator at 16MHz, with 15pF
capacitors), and now i can't reprogram the uc cause it wont oscilate,
thus the programmer (avrxs) doesn't recognize it. I've changed the
crystal for a 4MHz one but stil it wont start up. The avrxs reports
that there is a cable connected, but it doesn't recognize the device.
Is there a way to reset the fuse bits so it uses the internal
oscilator or something to solve this problem?

Thank you, Jony.

 

[Rich Webb]

Hello, I'm using an Atmel ATmega8515 micro controler, and i have a
problem writing the fuse bits. I did write them, but i think i did it
wrong (I'm using an external crystal oscilator at 16MHz, with 15pF
capacitors), and now i can't reprogram the uc cause it wont oscilate,
thus the programmer (avrxs) doesn't recognize it. I've changed the
crystal for a 4MHz one but stil it wont start up. The avrxs reports
that there is a cable connected, but it doesn't recognize the device.
Is there a way to reset the fuse bits so it uses the internal
oscilator or something to solve this problem?

The STK500 is often the best solution for dodgy AVRs. When all else
fails, you can use it in parallel programming mode.

You can try running the uC from an external CLOCK vice CRYSTAL. With one
of these guys http://dkc3.digikey.com/PDF/T042/0687.pdf you supply Vcc
and ground, and you get a clock. Feed that to XTAL1.