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

Valentin Longchamp wrote:

>
> Paulo Marques wrote:
>
>
> 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 !

Control loop as I used it means: read sensors, calculate actions, apply outputs.

Reading the encoders, in my purposed solution, should be done by the
microcontroller (at 5KHz or something like that) and the *total count* should be
sent to the iPaq at 50Hz.

The iPaq should never have to do low-level stuff like reading encoders or
generating PWM's.

The iPaq should be doing more mid-level (the encoder on motor A moved 23 ticks
and on motor B 16 ticks so my current position is <X,Y>) and high-level stuff
("where should I go", "build world map", etc.).

> 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 ...
>

Well, if this is a "I get a kick out of programming PLD's, FPGA's, building
surface mount PCB's, etc.", please don't let me stop you :)

This was just my 0.02 euros,

-- 
Paulo Marques
Software Development Department - Restinfor, Lda.
Phone: +351 252 290600, Fax: +351 252 290601
Web: www.grupopie.com
"In a world without walls and fences who needs windows and gates?"