Re: [iPAQ] Help : accessing the extension port (FAST IO mode) of the ipaq

Paulo Marques wrote:

>
> Are you sure you need all this bandwidth?
>
> A simple solution with a ATmega16 (for instance) that comunicates using
> the serial port is *much* easier to implement. The ATmega can be
> programmed in C using gcc, and the software can be downloaded through a
> simple programmer connected to a serial port.
>
> You can get the serial port on the iPaq to go up to 230400 (I think, but
> should be confirmed).
>
> If you have a 50 Hz control loop (just throwing some numbers), at 230400
> you can get 460 bytes IN and 460 bytes OUT on each control cycle,
> through the serial port.
>
> Unless you have image sensors involved here, I can't imagine why you'd
> need more bandwidth.
>
> On top of that, a microcontroller will already provide timers, PWM, A/D
> converters, etc., that will release real-time demands from the host.
>
> Of course I'm not saying that you don't need to use the bus (as I don't
> know the project), I was just curious about the "why" you would need it :)
>

I need that bandwidth because we realy want to have a high frequence on
reading the motor encoders : last year we had a 50 Hz control loop and
it was much too slow. We want to try 1 kHz this year !

Secondly, I realy want to know how to access that fast io port on that
ipaq : been searching info about that for such a long time ...

Val
Received on Thu Jan 15 2004 - 13:23:35 EST