Re: [avr-chat] "double check connections"

[Julius Luukko]

On Tuesday 13 November 2007, Marge Coahran wrote:
> I am using several STK500s with ATmega8515L chips to teach assembly
> language in a computer science course. Today two students got the
> error (below) from avrdude. As best I can tell, the serial port
> connections are correct and solid. Can this error also mean something more
> ominous, say that something on the chip or the board just got blown?
>

Hello all,

I am sorry, but I don't have the right answer to your problem, but similar 
experiences.

We have used STK500+STK501+ATMega128s several years (5 or so) now in a student 
laboratory. We have had many problems similar to yours with the combination. 
We have around 100 students yearly, so the use is quite demanding. As of now 
I think that only two ATMega128s have actually been damaged and it seems that 
in some processors the A/D converter or USART0 might have been damaged.

In some cases I have been able to communicate to the STK500 with AVRStudio, 
which might report that you have an old firmware version and suggests to 
upgrade it. I have done so and after that there hasn't been any problems with 
programming the chip with avrdude. Sometimes swapping STK500s and STK501s has 
also helped, I don't know why, but it has.

Time seems to correct the problem sometimes, so don't through the board or the 
chip away. Check again after a month or so. The problems seem to be bigger 
when the humidity is low (in winter time here in Finland) and therefore ESD 
is more of a problem. We haven't had any ESD protection in the lab, but now 
we are in the process of improving it. The coming winter will tell if the 
situation is any better.

Julius

-- 
D.Sc. Julius Luukko
Laboratory of Control Engineering and Digital Systems
Lappeenranta University of Technology, FINLAND
phone:+358-5-621 6713, fax:+358-5-621 6799, www: http://www.ee.lut.fi