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Dumb question - disable auto cool
shortyjacobs
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Posted on 02/22/2020 2:01 PM
I finally had a decently successful roast with my rPI-Arduino-TC4. At least, until it apparently decided my roast was over and kicked the fan to 100%, blasting the entire batch out the top and all over my workshop. FWIW, at the end of the roast I?m typically at 12% fan, and never over 25%.

I found a PID auto cool in the aArtisanQ_PID sketch. Comment it out? I don?t want the fan to drop to 0, or go to any setpoint really, I just want it to leave well enough alone.

Thanks!
-Keith
 
mg512
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Posted on 02/23/2020 1:52 PM
Oh, did it turn on the fan entirely automatically? I thought that only kicked in if you manually disabled the PID.

Anyway, yes, I think commenting that out should simply leave the fan at its previous level.
 
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shortyjacobs
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Posted on 02/23/2020 2:49 PM
I?m pretty sure it did, but honestly there was a lot going on :-). Thanks!
-Keith
 
shortyjacobs
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Posted on 02/23/2020 3:04 PM
OK, commenting it out in user.h caused a compiler error:
i.imgur.com/Gr2Yd4P.png

Commenting out the offending lines in cmndreader.cpp appears to have fixed it...we shall see on the next roast!
i.imgur.com/peEmySK.png
-Keith
 
greencardigan
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Posted on 02/23/2020 4:47 PM
The FAN_AUTO_COOL setting should only get activated if you stop the roast using the PID;STOP command.

The PID;STOP command does three things. Deactivates the PID, sets the heater output to 0, and the fan output to the FAN_AUTO_COOL level.

Alternatively, you can use the PID;OFF command which deactivates the PID only. When using this command, the heater output should remain as was last set by the PID.
 
shortyjacobs
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Posted on 02/23/2020 7:56 PM
Hrm, either I fat fingered something (Is there a PID STOP button? I'm pretty sure it's PID OFF in Artisan right?
Is there an event (other than one I purposefully create) that generates a PID OFF command?), or the controller just decided to go to 100%. Or maybe the SSR stuck closed? I started frantically hammering "Fan slow down" (well, down arrow, since I had the slider selected), and it did slow down. Regardless, I don't want auto fan overriding me, so it's good it's off now. We'll see if the max fan happens again, in which case it's probably an SSR going no bueno.
-Keith
 
greencardigan
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Posted on 02/23/2020 8:26 PM
I'm referring to a button or event you have created in Artisan that has an associated serial command being sent to the TC4. If you haven't set up any buttons or events that issue a PID;STOP command, then I have no idea why you got 100% fan.

Turning the PID off using the Off button in the Control dialog should issue a PID;OFF command to the TC4.

I'd recommend trying some runs without the heater connected and without beans. Just to get used to the process of starting/stopping roasts and all the buttons/sliders.

Also, there's the Heater and Fan Limits section in user.h that you could use to limit the maximum fan speed. However, I think I just noticed a bug in the code (the maximum limit for the output on OT2 may not be applied correctly). If you're using IO3 for the fan output it should be ok.
 
shortyjacobs
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Posted on 02/23/2020 10:36 PM
Thanks greencardigan. Yep, I had no custom events. Now I?m wondering if I was just unlucky and hit 15% fan speed. 15% fan speed, for some reason, is choppy. Maybe because it?s an even divisor of 60 Hz? For whatever reason, at 15%, my fan speed jumps all over hells half acre. 14% and 16% are fine. Might try swapping in a ?commercial? ZCD instead of my home built one, but doubt its that since the ZCD is upstream of the control logic.

I had run some test runs with pinto beans, but the shizzle never hits the fan until money is on the line. I?m using OT2 for fan output, but I haven?t set fan limits yet, (I like keeping my options open) so it?s not that. I also just recently switched from laptop control to raspberry pi control, and even though it?s a PI3, I frequently peg the processor and Artisan hangs for a few seconds, so that complicates things. A side effect of 1s sampling time? Who knows...it?s a fresh Raspbian install, not much overhead.

Anyway. Just managed a successful PID controlled 460 gram roast. I?m happy!
-Keith
 
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