bkubicek/Marlin — pull request #33 by j-c (2011-11-13 07:59:36+00:00)
Title: Calibration for initial PID(A) values

I based the calibration instructions off http://www.controlguru.com/wp/p89.html
Seems to work well to generate initial PID values from which to start tuning.

The only issue with this is that I can't accurately gather the process time due to the limited memory. The temp increase is not linear so it's hard to calculate when it has hit 63% of the maximum temp (given a fixed heater PWM output). I think I have a way, but I'll need to fix the start of the routine where I attempt to figure out what constant PWM value I need to hit a given target temp.

Anyway, I'm not sure if this will be useful anymore since reading on the ultimaker mailing list that you and ErikZ are working on a graphical tuning tool.