Umm... I'm getting a little bit confused with this thread now but tI think that quote was for the original thermostat operation. The PIDs were autotuned and sit tight at setpoint with no major issues. I had a few probs with the PID displaying Fahrenheit as I think it was basically just converting Celcius into Fahrenheit with a nasty integer or roundoff error in the maths. The fuzzy logic was being highly illogical too
Set on normal PID mode with display in C it is performing admirably. The only con I can think of is that I now can see the temperature so always want to wait until it gets back to temperature before pulling the second shot! This seems like a loooong time but its really a few mins. I think this is where we can make use of the fine tuning - to get a better recovery time. My settings give almost no overshoot - I think I can cope with a little overshoot say 1C to get a faster recovery. So I will look forward to hearing of this fine tune procedure
While I remember, Lukas, if you have the manual for the PID (did you get the ebay one me and Jon got?) there are a couple of mistakes:
The example setup (an espresso machine boiler coincidently) states heating/cooling (r/d) = 1 (cooling) it SHOULD be 0 (heating)
The manual also states default temperatures of 80C... on my PID this setting showed as 0800, so I assumed the last digit was a decimal place. Wrong. the default on mine was 800C, when you set the temperatures each digit is 1C so 80C would be 0080. No wonder my espresso machine was glowing red when I first set it up the PID was trynig to hit 800C