PID Tuning Help

Troubleshooting
1

Hi,

I’d really appreciate some assistance in tuning my brewpi setup. Please note i’m using the arduino version ported to the ESP8266 (Brewpiless).

The system seems to be overreacting. The fridge temp sensor is hanging on the left of the image and the heating element is at the bottom of the pic (75W). One of the images below shows when I added the dry hop and the resulting over reaction / oscillations.

Brewpiless2
Brewpiless2.png983×531 49 KB
Brewpi
Brewpi.png988×530 110 KB
IMG_20170910_095714 (1)
IMG_20170910_095714 (1).jpg3456×4608 1.43 MB

Parameters are the defaults:
“pidMax”: 10.000
“Kp”: 5.000
“Ki”: 0.250
“Kd”:-1.500
“iMaxErr”: 0.500
“idleRangeH”: 1.000
“idleRangeL”:-1.000
“heatTargetH”: 0.299
“heatTargetL”:-0.199
“coolTargetH”:0.199
“coolTargetL”:-0.299
“maxHeatTimeForEst”:600
“maxCoolTimeForEst”:1200
“fridgeFastFilt”:1
“fridgeSlowFilt”:4
“fridge SlopeFilt”:3
“beerFastFilt”:3
“beerSlowFilt”:4
“beerSlopeFilt”:4
“lah”:0
“hs”:0

Thank you so much for taking the time and any help is massively appreciated! Thanks again.

2

You have your sensor taped to the side of the carboy and it is measuring 50% fridge temp and 50% beer temp.
The Arduino version of BrewPi wasn’t built to handle that. It expects a slow changing beer temperature to which it can adjust the fridge setting. Your beer temperature is changing even quicker than the fridge temperature.

3

Hi,

Thanks for the reply - so first thing to try is get a thermowell?

Cheers!

4

Yes. That will do more than anything you can do in software.

5

You might try putting a small fan to circulate air, I have mine taped to the outside and holds within .1 degrees F.