>HI
>        I am new to the PICLIST. I am now presently trying to implement a PID
>controller and a trajectory motion control. I have look up the Embedded
>Control Book,AN532, and it has a very good reference. But the problem is
>that there are so many interrupts and function. Does anyone know of a
>simpler way of writing the PID algorithm?
>        Presently, I have a PIC which calculates the velocity and the position
>of the motor. But how am I going to get the info from the PIC?
>Especially when it is has a 8-bit output for the velocity and position.
>        Another question is that can I use the same crystal for both my PIC?
>        Thanks, with regards,
>
>....."The journey of a thousand miles begins with a
>small step in the right direction.".......
>

The right direction might involve reading "CONTROLLER TUNING AND CONTROL
LOOP PERFORMANCE," subtitled "PID Without the Math." Paperback, $US15. This
is a Primer written by David St. Clair and published by Straight-Line
Control Company INC, 3 Bridle Brook Lane, Newark, DE 19711-2003. Voice
302-731-4699 Fax 302-454-8599. Email dwstclair@aol.com. There is also an
article "How to Write a PID Algorithm" by Garth Caddy in the May 1997 issue
of EMBEDDED SYSTEMS PROGRAMMING.

In the free domain, mike#14 posted a back in June that there was a PID
simulator available at http://www.coast.net/SimTel/SimTel/msdos/sysutil,
called PIDSIM22.ZIP. Don't know if it's still there.

None of these resources are PIC-specific, but should be pretty helpful if
you are already comfortable with the PIC part.

Reg Neale