AVR-Chat

Hi all!

--- In AVR-Chat@yahoogroups.com, "Ivan Vernot" <ivernot@o...> wrote:
> Marcus,
> I have no solution but a couple of suggestions - HTH
> 1.Take the MCU that does not run on Board 2 (the non working board) and
> program it with the .hex file for Board 1 (the b board that does work!).
> Plug the micro into Board 1 and this will prove whether micro is faulty.

I did so. After programming a micro on board 2 (non-wirking) it didn't work on any board 
further on...

> 2. Check the fuse bits (yes again ;-)) Check you BOD bits (you don't say
> what the difference between Board 1 and Board 2 is. Are the both 5V VCC? Is
> one 3V and the other 5V?)

Both 5V, only different frequency, port-config and so on.

All fuses leaved unprogrammed (blank box in PonProg). 
During test I don't need code protection or so and brown out is not enabled. 
I thought to leave CKSEL and CKOPT unprogrammed (8/16MHz Xtal) - that 
runs on the 16MHz board (1) quite well.


> 3. Check your Rest line. If the Xtal runs - is the micro being held in
> reset?

Don't think so. Pulled it low after programming by hand and shortened the
pull-up-resistor afterwards to ensure it goes as high as possible - nothing.
What makes me wonder is the running XTal and the fact that you can 
flash the device correctly - why the hell doesn't it start running ???

> 4. Take the non working code and strip everything except a bit toggle (or
> LED blink) in the main loop and program the no working board with that -
> check that the simple program is working. (you might not be setting up the
> stack properly for example.)

Done so. All ports out, all ports low, setting one defined port bit high. No ints, no 
nasty stuff - nothing.

> 
> Try these things and let us know how you get on. Good Luck.
> 

Well, I'll have to hurry to my desk now - time for work. I'll try once more,
but it seems to me that the program cycle on the faulty board has killed the micro... 
... want to know why...


Thanks'n CYa later

Marcus