diff --git a/pid.md b/pid.md
index 3cf9f96..d9770d0 100644
--- a/pid.md
+++ b/pid.md
@@ -1,52 +1,49 @@
-* create a stepped schedule
+Tuning PID Vaules
+=================
 
-200
-220
-200
-220
+## The Goal
+A controller with properly tuned PID values reacts quickly to changes in the set point, but does not overshoot much.  It settles quickly from any oscillations and hovers really close to the set point.  What do I mean by close? The average error for my kiln on a 13 hour schedule is .75 degrees F... and I have a noisy thermocouple, so it is possible to do even better.
 
-* set i=0
-* set d=0
-* set p=5
+## Try the Existing Values
 
-run schedule
-if oscillation is sustained stop
-otherwise, double p
+My kiln is Skutt KS-1018 with a kiln vent.  Try the current settings for pid_kp, pid_ki, and pid_kd and if they work for you, you're done.  Otherwise, you have some experimentation ahead of you.  The following exercise took me about 2 hours of testing. 
 
-once oscillation is sustained
-* record P as Ku
-* record period of oscillation as Pu
+## The Tuning Process
 
-set p=Ku/1.7
-set i=Pu/2
-set d=Pu/8
+* in config.py...
+* set pid_kp to 1
+* set pid_ki to 0
+* set pid_kd to 0
+* run a test schedule. I used a schedule that switches between 200 and 250 F evey 30 minutes.
 
--------------------------------------------------------------------------------
-another method (for just PI control)
-https://pdfs.semanticscholar.org/e719/f259f6c93b9a897a214824e562c886aa80b9.pdf
-
-
-use step schedule
-set d=0
-set p=1
-you should see some overshoot and barely observable undershoot
-if not, change p until that's true (up or down)
-
-next measure T between high peak and low peak
-set i=T*1.5
-set p=.8*lastp
-
-p=1*.8 = .8
-i=1040-315 = 725s * 1.5 = 1088
-
--------------------------------------------------------------------------------
-https://www.eurotherm.com/pid-control-made-easy
-
-similar to above for PI
-
-p=2*25=50 (that's 25F overshoot times 2)
-i=725*1.5 = 1088
-d = 1088/5 = 217
+What you are looking for is overshoot (in my case 25F) past 200F to 225F. The next thing the controller should do is settle to just below the set point of 200F. If these two things happen, great.  If not, you will need to change pid_kp to a higher or lower value.
+
+Once you get the overshoot and minimal undershoot, you need to record some values.  First grab the overshoot... in my case 25F.
+
+* set pid_kp = 25
+
+Measure the time in seconds from high peak to low peak. In my case this was 725 seconds.  Multiply that number by 1.5 to get the Integral.
+
+* set pid_ki = 725 * 1.5 = 1088
+
+Now set the derivative at 1/5 of the Integral...
+
+* set pid_kd = 1088/5 = 217
+
+in essence these values mean...
+
+| setting | Value | Action |
+| ------- | ----- | ------ |
+| pid_kp | 25 | react pretty slowly |
+| pid_ki | 1088 | predict really far forward in time and make changes early |
+| pid_kd | 217 | heavily dampen oscillations |
+
+Now, run the test schedule again and see how well it works.  Expect some overshoot as the kiln reaches the set temperature the first time, but no oscillation.  Any holds or ramps after that should have a smooth transition and should remain really close to the set point [1 or 2 degrees F].
 
 
+## Troubleshooting
 
+* only change one value at a time, then test it.
+* If there is too much overshoot, decrease pid_kp.
+* If the temp is always below the set point, increase pid_ki.
+* make sure pid_kd is always 1/5 of pid_ki