Re: [avr-chat] AVR ISP and/or AT90LS8535 questions.

[Russell Shaw]

Andy Warner wrote:
> I've finally broken the last of my cheapo AVR ISP
> (RS232) programmers. I'm fairly sure I fried the
> AT90LS8535, by hotplugging it into a target
> board by mistake one too many times.
>
> I used to just buy another; they were cheap enough.
> Alas, no longer, because they're obsolete, and I can't find
> any stock at the usual distributers.

It would be useful to add a 100mA fuse and shunt 5.6V zener
diode to the next one.

> So, I'd like to ask, in no particular order:
>
> o what's your favourite RS232 AVR ISP programmer,
>   perhaps one that's a little better protected against
>   transients/wear and tear than the AVRISP ? I use
>   terminal servers to connect to the programmers, so
>   I need something that implements a real protocol, not
>   just bit-bashing. USB-based solutions need not apply
>   at present.

I'm still using my avrisp.

> o Anyone know of a secret supply of AVRISPs, at
>   a reasonable price ?

Maybe on ebay some time.

http://business.search.ebay.com/avr_Business-Industrial_W0QQcatrefZC6QQcoactionZcompareQQcoentrypageZsearchQQcopagenumZ1QQfposZ3216QQfromZR10QQfsooZ1QQfsopZ1QQftrtZ1QQftrvZ1QQsacatZ12576QQsadisZ200QQsargnZQ2d1QQsaslcZ2QQsbrftogZ1QQsofocusZbs

> o Anyone have a couple of AT90LS8535 chips (also
>   obsolete), because I can still program the part (I know
>   this because I tried to reclaim it by reloading the firmware
>   using avrstudio) - and I would be happy to replace this
>   chip and see if it came back to life (there's not much else
>   in there to go wrong really.)
>
> o Anyone know of any other techniques to debug/repair these
>   units ?

You should be able to use a mega8535 as a drop-in replacement if
you set the extra fuses appropriately. You might not need a low-vcc
version if the application isn't too demanding.