No code right now - we have been working on one and it seems to be functioning, but every time I think it is ready to show off, I find something I want to tweak. 
 
Try the following links for a good description of a PID.  In particular, the uwaterloo site has a succinct definition that you can code from.

http://www.siebe-env-controls.com/news/links/pid.htm

http://www.expertune.com

http://real.uwaterloo.ca/~robot/Mc_sw.html

Dan
-----Original Message-----
From: Samuel Sosa <samuelsr@CANTV.NET>
To: PICLIST@MITVMA.MIT.EDU <PICLIST@MITVMA.MIT.EDU>
Date: Thursday, September 23, 1999 6:38 AM
Subject: looking for PID algorit

Hi, i am searching for a algorit or rutine, what tell me how make PID control, 
 
Can help me.
 
Thank You Very Much. 
 
 
Samuel Sosa
samuelsr@cantv.net
I.U.T. Valencia.
 
phone: 58 41 0149497620
fax:      58 41 311330
 
Valencia, Carabobo, Venezuela.
Z.P. 2001, Apartado Postal (POB) # 2176