Re: [avr-chat] Crystals (was ATmega32 @ 16MHz : fuse bits ??)

[Graham Davies]

Vincent,

Regarding "... if my fuse bits are correct, and it's not the crystals or
capacitors, then I can't see what it could be ...":

Well, you could, I suppose have the crystal-in-a-million that is just plain
dead.  But, I would not tell you that you need to agonize over the choice of
a crystal and capacitors.  Just try another "microprocessor crystal" and
capacitors in the vicinity of 22pF.  What I suppose I was hinting at is that
you should carefully check the wiring of the crystal and capacitors to the
MCU.  Look for opens and shorts and dry joints.  I don't recall you
mentioning the hardware arrangement you are working with, but now that you
are writing about "hand made/DIY" cables it is, perhaps, an economy set-up.
Oh, and what is the exact manufacturer's part number on your MCU?

Regarding the JTAG cable:

As Joerg says, AVaRICE + GDB is your tool set (although I'm not unhappy with
AVR Studio myself) and works with JTAG ICE Mark I "clones".  If you decide
to purchase an AVR ICE-Cube and you subsequently decide you don't want it
*for any reason* I will refund the full purchase price, less shipping and
handling.  Airmail letter post to Europe is about $3.20 US.  Or, since
producing the ICE-Cube, my Olimex clone has just gathered dust and you could
have that for a nominal fee.  However, it was dissatisfaction with the
Olimex that started me in with the ICE-Cube so YMMV.  I will also throw in a
crystal and capacitors, although the closest I can get to 16MHz from stock
is 15.36MHz.

Regarding programming the JTAG fuse:

Don't do this.  If you need to press the JTAG pins into service for other
functions, turn off JTAG in software instead.  Then, before your software
gets to that point, you can get into the JTAG port.

Graham.
http://www.ecrostech.com