Autotune filter direct not functioning about quickpid HOT 4 CLOSED

Yes, the autoTune feature can get stuck in the stabilizing mode with different systems other than using a basic Arduino with 10-bit ADC input and 8-bit PWM output and RC filter. I'll be working on an update to autoTune to improve compatibility with other systems (see issue#13).

Currently, it's assumed the user knows what input value to expect for a given output value. The update to autoTune will attempt to simplify things by only requiring the setpoint and some other parameters to run.

Sorry I'm not familiar with your system, but for now I'd suggest trying to manually the PID values or using an online or other autotune tool to get the estimated values.

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Thanks for making this PID library!

My own experience with is that even when using the 10bits ADC, 8 bit pwm and the filter with a diode and an LED and it still gets stuck in stabilize. The responses of diode and LED to input/output are very linear, but there is some noise of course. Or maybe the change in measured light is sometimes not detectable over the noise for a given change in PWM? Maybe the autotune is a bit overly sensitive?

Currently, it's assumed the user knows what input value to expect for a given output value.
I know this, but it is not clear to me how this knowledge could help me to run autoTune.

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@ilikegitlab, If the LED is connected to the PWM output, then this will impose a load on the output pin. In this case, the output pin's voltage will get reduced to 4.8V (for example). Now the expected response (4 counts input per 1 count output) would get reduced by 4%, causing autotune to get stuck.

I'm working on a major update to autotune where the stringent input to output relationship is removed. The new autotune will use a step-test method similar to described here. However, instead of graphical fitting, autotune will analyze the actual "s" curve from test results by using a sliding tangent line. I'm getting good results with the TCLab hardware, but have further development and testing (and little time), so it could take a while before its ready.

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I've Removed AutoTune in preparation for a new AutoTune library (sTune) compatible with QuickPID, PID_v1 and others. Should have this ready in the next few weeks ... more details to follow.

Closing the previous AutoTune issues as these will be successfully addressed by the new library.

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