AVR-Chat

I'm trying building my first circuit using ATmega8535 using ATMEL AVRISP programmer.
What do you suggest me :

- can I use breadboard or 1000 holes circuit board ?
- can I use what Vcc is necessary ?

[Non-text portions of this message have been removed]

Has anyone seen Kathy on chat or otherwise lately?

At 03:46 AM 7/09/2006, you wrote:

>Has anyone seen Kathy on chat or otherwise lately?

I hope our "list Mom" is well, last time I heard from
her was early June when she sent me a "present", perhaps
she is very busy making lots of money :-)


Regards

John Samperi

********************************************************
Ampertronics Pty. Ltd.
11 Brokenwood Place Baulkham Hills, NSW 2153 AUSTRALIA
Tel. (02) 9674-6495       Fax (02) 9674-8745
Email: john@ampertronics.com.au
Website  http://www.ampertronics.com.au
*Electronic Design * Custom Products * Contract Assembly
********************************************************

She posted on the [codevisionavr] group on 8/31/06.

Aaron

Dave VanHorn wrote:

>Has anyone seen Kathy on chat or otherwise lately?
>  
>

I know this is perhaps a bit off topic but I have several boards with
PIC16F877 processors driving an HC595 shift register and the output pins
from the pic driving the HC595 are virtually all glitches.

It is hard to pick up a high or low as such on the logic analyser other
outputs seem ok, has anyone any idea what may be causing this. 

And yes I do not like pic's I normally use AVR'S.

 



[Non-text portions of this message have been removed]

Check your scope ground.  I use all kinds of different embedded 
processors, PICs included, and I've used the F877 with 'HC595's too with 
great success.  What is your code doing and are you constants switching 
the DDR from inputs/outputs?  How is your power rail?  If it is bouncing 
around so too will logic levels.  Basically, you haven't given enough 
information for any kind of a suggestion to be made.

DLC

OWEN-A wrote:
> I know this is perhaps a bit off topic but I have several boards with
> PIC16F877 processors driving an HC595 shift register and the output pins
> from the pic driving the HC595 are virtually all glitches.
> 
> It is hard to pick up a high or low as such on the logic analyser other
> outputs seem ok, has anyone any idea what may be causing this. 
> 
> And yes I do not like pic's I normally use AVR'S.
> 
>  
> 
> 
> 
> [Non-text portions of this message have been removed]
> 
> 
> 
> 
>  
> Yahoo! Groups Links
> 
> 
> 
> 
> 
> 
> 
> 

-- 
---------------------------------------
Dennis Clark    TTT Enterprises
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On Thursday 07 September 2006 09:47, OWEN-A wrote:
> I know this is perhaps a bit off topic but I have several boards with
> PIC16F877 processors driving an HC595 shift register and the output pins
> from the pic driving the HC595 are virtually all glitches.

If you are trying to cascade 595's watch the setup&hold time from the Hq' output
to the rising edge of the clock.  The 595 clock on the wrong edge when used
in a cascade, causing a race condition.  If you are bit-banging some pins watch
for this race as well.  The internal I/O clock synchronization of the PIC and AVR
I/O can mislead you, when it comes to setup&hold issues driving clocked logic,
if you are not aware of the internal operation of the I/O.


The TPIC6595 clocks on the falling edge so they cascade safely.
http://focus.ti.com/docs/prod/folders/print/tpic6595.html
Note that the 6595 is a five volt only part unfortunately.
There are also the TPIC6/a/b/c/595 parts.

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