AVR-Chat

For my next project, I'm fairly convinced that there are no reasonable 
PIC solutions that fulfill my requirements so I'm ready to switch over 
to the AVRs.

I need at a minimum 46 I/Os, which Microchip accommodates fairly easily 
but Atmel doesn't seem to have anything between 35 and 53 pins.  Since 
this is a 'one of' project, the ability to etch and solder by hand is 
something of concern.  I've trolled a bunch of data sheets but can't 
find a relatively easy to solder package with >46 pins from Atmel.  Did 
I miss something or do I just need to bite the bullet?

Second question:  My experience with LCDs is limited to working with 
serial->parallel shift registers in order to interface with the LCD. 
What is the general feeling about using a 'LCD' AVR as a possibly more 
convenient method of communication with the display?

Third question:  I have a ICD2 debugger which I use constantly when 
developing PIC based projects (stems from my inability to read my own 
code :)  What is the AVR equivalent in terms of ability and cost?  Am I 
correct in assuming that a decent AVR debugger will also do in circuit 
programming (The programmer I own is only capable of writing to very 
mature AVR products)

Looking forward to turning to the dark side of the Force,
Nate

At 10:34 AM 25/05/2006, you wrote:
>I need at a minimum 46 I/Os,
........
>but Atmel doesn't seem to have anything between 35 and 53 pins.

How are you going to fit 46 IO in a 35 pin packages? :-)
There are lots of 40 pin PDIPs in Atmel's range but not
with that many IO obviously. The Mega 64 or 128 can give
you up to 53 IO but it only comes in SMD. You can buy
adaptor boards for them however.

 >do I just need to bite the bullet?
Yes or see above.

>I have a ICD2 debugger
..............
>What is the AVR equivalent in terms of ability and cost?

JTAGICE which you can build yourself or buy it for about US$40.00
I believe.


Regards

John Samperi

********************************************************
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Tel. (02) 9674-6495       Fax (02) 9674-8745
Email: john@ampertronics.com.au
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*Electronic Design * Custom Products * Contract Assembly
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If you've never seen it before, check out this video:

http://region.bdmicro.com/smt1.mov

Looks almost too easy, eh?  ;)

I'm feeling brave, and might try a TQFP on my next project.

Ryan

--- In AVR-Chat@yahoogroups.com, Nathan Nottingham <nate@...> wrote:

> I need at a minimum 46 I/Os, which Microchip accommodates fairly easily 
> but Atmel doesn't seem to have anything between 35 and 53 pins.  Since 
> this is a 'one of' project, the ability to etch and solder by hand is 
> something of concern.  I've trolled a bunch of data sheets but can't 
> find a relatively easy to solder package with >46 pins from Atmel.  Did 
> I miss something or do I just need to bite the bullet?

Even easier, get a concave tip ( readily available ) & try the drag technique. 
google drag soldering tqfp

keys are lots of flux & keep the iron temp no more than 250C, magnification is 
helpful particularly at first so you understand what is really happening

gotta fly

Cheers

Don


David VanHorn wrote:

> 
>  
> It's really not that hard, just peg the corners to that you know you're 
> centered in both axes, flood and braid.
>  
> Go with it.
>  
> 
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David VanHorn wrote:
> 
>  
> It's really not that hard, just peg the corners to that you know you're 
> centered in both axes, flood and braid.
>  

I posted an Instructable on one way to hold down chips when doing that 
initial soldering:

http://www.instructables.com/ex/i/665BBCB442D41029AC23001143E7E506/

Also, there's one on soldering leadless chips:

http://www.instructables.com/ex/i/0E9564B43CE71029AC23001143E7E506/

And a tutorial on using an electric skillet for reflow work:

http://www.sparkfun.com/commerce/present.php?p=Reflow%20Skillet

Thanks,
-- 
Ned Konz
ned@bike-nomad.com
http://bike-nomad.com