AVR-Chat

On Apr 20, 2009, at 11:38 PM, Guido Helmstetter wrote:

>
>
> Hi Jim
> Well you are correct why not loop around, as powersaving is not the  
> main concern here and truly this is just for the sake of  
> understanding how to wake up from sleep mode with interupt.
> As I am a beginner and try to work out all the if, but and why some  
> things may make no sense.
> So thanks again and we put this one to sleep
> guido
>
>
> Enjoy a better web experience. Upgrade to the new Internet Explorer  
> 8 optimised for Yahoo!7. Get it now.
>
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>
>
> 
Hello, Guido -

My point is this.... you need to learn to live within the limits of  
the processor you have chosen. That is something we all have to do, at  
one time or another.

One of those limitation is that it is VERY hard to use (well) the same  
pin as an input and output. It is one thing to switch a pin back and  
forth (that is what a TWI data pin does). Your problem, if there is  
one, is that you have chosen a task that does not fit the processor,  
or a processor that does not fit the task.

This is often a difficult idea for beginners to learn. There are many  
AVRs for a good reason. It allows you to choose a "best" one for your  
application. Sometimes, however, that is a hard choice. Sometimes, it  
is a choice we don't want to have to make because we already have a  
particular device on-hand.

Best wishes,
Jim



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