I'm a home brewer. I make wine and brew beer but the temperature needs are similar so I created an node-red app that reads temperatures from several DS18B20 temperature probes and uses them to either turn on a heater or a freezer to maintain a constant temperature. As of now I can maintain a prett…

My brewbox lid is open and I'm waiting for 75F. PB is set to 5 with Ti still at 57600. When the pv settles to steady state and if it's not at setpoint, say above, do I decrease the Ti to make it approach setpoint? Is the procedure different for above sp or below sp?

[image] Backup: When the pv settles to steady state and if it's not at setpoint ... It will be at setpoint, that's what the integral does. If you look at your last chart you can see it in action. Between 09:00 and 13:00 the temperature does not change, but because the temperature is below t…

Well, this is just about perfect. I only reduced the PB to 5 from 10 and this is the result. [image] This is a 16 hour graph and the pv was within 1F of setpoint in less than 6 hours. Taking into consideration the aerobic lag time of the yeast this couldn't be better. The only wild card now is…

Assuming the self generated heat comes on slowly then the integral should have little trouble compensating. Did you accidentally change the setpoint at 21:30? You could get it in there quicker by reducing the PB further so you get a little overshoot, but it sounds like you don't want to cool it do…

Yes, I was intending to set my aging temp a degree lower and did the brew temp instead. I'm happy with it the way it is and I agree that the yeast generated heat won't be a factor that requires compensation. It may build quickly, a few hours to peak, then gradually reduce as the sugars are consume…

As long as it builds over a few hours the integral should take it out. I would wait till it is all working before publishing, otherwise you won't know whether there is some minor error in there.

Good. compensating for larger or smaller batches would be a lot of work. :slight_smile: I have a beer kit on hand, I'll see if I can work in a live batch this week and give you an update. Cheers! [image]

I didn't have the yeast I needed for my beer kit so I put together a batch of orange wine. 3 gallons volume in a 5 gallon bucket. [image] The graph is 36 hours with the bucket into the freezer at about 1pm yesterday. The must was at 99F to start. I forgot about the boiling water addition and …

While there is a temperature difference between the box and the must then the must will not all be at the same temperature. The outside will be lower than the centre and there will be convection currents circulating in the liquid. If, when you added the yeast, the probe did not end up in exactly t…

I did stir in the yeast but the liquid added was only a couple ounces. It is a bit of a shock that there would be that much difference in temperature between the core and outer edge of the bucket. My temp probe is about 1/3 of the way in from the edge. I could really get involved in adding someth…

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DS18B20 smoothing and PID tuning

General

Paul-Reed 10 March 2019 23:20 227

Or a link - DS18B20 PID Tuning on the warm side

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DS18B20 smoothing and PID tuning

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