Keg Cop: Keg Monitoring and Control

[rkhanso]

Well, Keg Cop is running with 4 temp sensors connected, I just don't have a solenoid connected and it actually controlling the Kegerator. I'm checking it's running stability only. I can easily switch the Kegerator over from BrewPiLess to Keg Cop, but thought I'd just let it simmer on its own to see how it ran.
If the web server is not an indication of how it would really control temperatures (the controller not locking up, resetting, losing configs, etc), that's good news.
Later today or this week, I'll get Keg Cop actually controlling the kegerator temps and also have CraftbeerPi3 running to measure/graph temperatures to see if when the webserver acts up and the ESP crashes/reboots, if the temp control continues to work through that.

 

[LBussy]

Change the settings (setpoint, offsets, whatever) and observe that they remain over a crash/reboot.

 

[rkhanso]

I have both Keg Cop and BrewPiLess-32 running. Keg Cop is controlling the Kegerator and BrewPiLess is only monitoring temps, since it'll log as long as the web page is open. I also have Keg Cop sending data to Home Assistant via mqtt. I won't keep the Keg Cop web GUI loaded in a browser and see if it's more stable, monitoring with BrewPiLess-32 to ensure temp control is still working even if/when the webserver and GUI stop working.

One thing I'm seeing in Home Assistant logs is that the kegerator compressor control seems wrong. It's being reported that Keg Cop is telling cooling to happen in some very short intervals. I have the SSR running the compressor connected to the C terminal on the Keg Cop board, not the S terminal. I also shut off the Tower Fan function in the GUI, just to be sure.

I visually/physically monitored to see if the mqtt data is correct or not. Of course, it is.

Isn't this frequent on/off hard on the compressor? When using BrewPiLess and CraftbeerPi3 to control the Kegerator, the compressor would come on for about 10-15 min every 1-2 hours.

September 12, 2023
Keezer Chamber Cool turned off \
2:41:46 PM - 6 minutes ago      <--on for only 50 seconds?
Keezer Chamber Cool turned on /
2:40:56 PM - 6 minutes ago     <<--off for 8.5 minutes
Keezer Chamber Cool turned off  \
2:32:26 PM - 15 minutes ago      <--on for only 50 seconds?
Keezer Chamber Cool turned on  /
2:31:36 PM - 16 minutes ago  <<--off for 8.5 minutes
Keezer Chamber Cool turned off \
2:22:56 PM - 24 minutes ago     <-- on for only 40 seconds?
Keezer Chamber Cool turned on  /
2:22:16 PM - 25 minutes ago  <<-- off for 8 minutes 50 seconds
Keezer Chamber Cool turned off \
2:13:26 PM - 34 minutes ago    <-- on for 40 seconds?
Keezer Chamber Cool turned on  /
2:12:46 PM - 35 minutes ago
Keezer Chamber Cool turned off
2:03:36 PM - 44 minutes ago
Keezer Chamber Cool turned on
2:02:56 PM - 44 minutes ago
Keezer Chamber Cool turned off
1:53:46 PM - 1 hour ago
Keezer Chamber Cool turned on
1:53:06 PM - 1 hour ago
Keezer Chamber Cool turned off
1:44:16 PM - 1 hour ago
Keezer Chamber Cool turned on
1:43:36 PM - 1 hour ago
Keezer Chamber Cool turned off
1:34:16 PM - 1 hour ago
Keezer Chamber Cool turned on
1:33:36 PM - 1 hour ago
Keezer Chamber Cool turned off
1:24:06 PM - 1 hour ago
Keezer Chamber Cool turned on
1:23:26 PM - 1 hour ago
Keezer Chamber Cool turned off
1:11:56 PM - 2 hours ago

 

[LBussy]

Do you have anything in the kegerator? If there's no thermal mass in there and the evaporator is cooling that quickly (or the probe is close to the evaporator or there's no fan) then I can see that happening. What did BPL tell you about the temps? What does your serial log tell you?

The min on/off/and loop times are in config.h:

https://github.com/lbussy/keg-cop/b...b9b9a290880b8741026aaf/src/config.h#L503-L541
It's a simple thermostat, albeit with some filtering provided by a circular buffer.

 

[rkhanso]

There is nothing in the kegerator right now.
When running BrewPiLess-32 controlling the Kegerator the past couple weeks (again, nothing in the Kegerator), it operated what I consider normally and how I've seen it run the past 4 years whether anything was in the kegerator or not (similar operation when using CraftbeerPi3).

For example, with the Kegerator empty, here's how it ran with BrewPiLess - compressor turning on about 3x per hour:

Should Keg Cop be running this much differently than the other controllers I've tried? If so, then I'll adjust my expectations.
I'll throw in a keg of water and strap the keg sensor to it and see if there's a difference....though I didn't have that for the BrewPiLess screenshot above.

 

[LBussy]

Should Keg Cop be running this much differently than the other controllers I've tried? If so, then I'll adjust my expectations.

Yes, the purpose of Keg Cop is not precise fermentation control. It's a simple thermostat, where all the rest use a PID loop and more restrictive timers.

I can control the temperature reasonably (i.e. as good as Inkbird) and a keg in my keezer and a simple recirculating fan keep the cycling down.

 

[rkhanso]

Putting a half-filled keg of water and the keg temp probe on it with a bungee and half a foam pool noodle over it does reduce the number of cycles per hour. It comes on about 6x per hour now instead of 3x per hour when using BrewPiLess or CraftbeerPi3. Is this too frequent and for too short of a time period? I've always heard it's better for compressors to run less often, and for longer at a time.

Keezer Chamber Cool turned on
11:21:56 PM - 3 minutes ago
Keezer Chamber Cool turned off
11:14:46 PM - 10 minutes ago 
Keezer Chamber Cool turned on 
11:10:36 PM - 14 minutes ago 
Keezer Chamber Cool turned off
11:04:16 PM - 21 minutes ago 
Keezer Chamber Cool turned on 
10:59:56 PM - 25 minutes ago 
Keezer Chamber Cool turned off
10:53:36 PM - 31 minutes ago
Keezer Chamber Cool turned on
10:49:06 PM - 36 minutes ago
Keezer Chamber Cool turned off
10:43:16 PM - 42 minutes ago
Keezer Chamber Cool turned on
10:37:46 PM - 1 hour ago
Keezer Chamber Cool turned off
10:30:36 PM - 1 hour ago   
Keezer Chamber Cool turned on 
10:23:46 PM - 1 hour ago       
Keezer Chamber Cool turned off
10:21:59 PM - 1 hour ago

 

[LBussy]

Compressor off time is a requirement to prevent trying to start the compressor when there is a pressure differential that causes it to be hard to start. A capillary tube on most refrigerators maintains the differential when running and causes the evaporator to absorb heat. Fairly shortly after the compressor turns off, this pressure normalizes because the capillary tube is allowing it to do so. I would not imagine this would take longer than 30 seconds on most refrigerators.

That said, there is a reasonable argument that turning on is still the more wear-inducing part of a refrigerator cycle. That's why I created some relief from the potential for the simple thermostat to cycle a compressor rapidly. The minimum off time on this system is five minutes, and the minimum on time is governed by the circular buffer that averages the temperatures over a minute as well as a minimum on time of two minutes. This is fairly similar to what all of the fermentation controllers have on top of a PID loop to run the cooling.

The HASS system only allows two states for those control points, on or off. Keg Cop has seven states to manage the cooling. HASS shows cooling on when the system is in TSTAT_COOL_ACTIVE, which is ONLY when the system is cooling AND when the system is not waiting for MIN_ON time. In other words, if the system decides 30 seconds in that it's cooled enough, it will switch to TSTAT_OFF_MINON, and HASS will show it as other than on, which is off, because it is waiting for the compressor to finish the two-minute minimum on time. If, while it is waiting, it decides it needs to cool again, then the state will switch back to TSTAT_COOL_ACTIVE, and HASS will again show it as being on. All this time, the compressor did not stop.

In other words, you are using a nice-to-have external display with limitations in the display states to suggest that your system is having an issue. Plug in a serial monitor or watch it via telnet and view the cooling operation there if you need to validate this.

You've also not said whether you have a circulation fan inside the chamber - this is highly recommended for fermenters and in a kegerator for the same reason. Most kegerators have no active airflow; using a fan will keep the system more stable. I use both a circulation fan and a tower fan for this reason.

 

[rkhanso]

Looking on Github for the cases. Is there supposed to be a bottom of the Daisy Chain board? I see 9 different tops but no bottom.

 

[LBussy]

Nope. Those clip over the PCB. Test one, and make sure it fits correctly. “Works for me” but you may have to scale up or down depending on your setup.

 

[rkhanso]

@LBussy - what is intended to be put in the left side of the main enclosure?
I have a 2-channel relay board but the holes don't line up with the screw posts. But I suspect a 2-channel relay is the intent of the left side.

I'm running an SSR to control my compressor. Will the ubiquitous blue 10A relays handle the fridge compressor? I think I burned one of the blue mechanical relays out when trying to control a compressor in the past. Wondering if I should give a mechanical 10A relay a try again or if I need to print a case for the SSR.

 

[LBussy]

Yes, that's for a 2-Ch relay. Some fit better than others. On a couple I was only able to get one screw in. That's fine. Chinese and standards do not seem to cross paths.

 

[lagerbeer666]

Kegcop MQTT to Home Assistant works great:

 

[LBussy]

Kegcop MQTT to Home Assistant works great:

Thanks for the report!

 

[rkhanso]

Kegcop MQTT to Home Assistant works great:

Does yours ever stop communicating to HA via MQTT after an extended period of time and just show "Unavailable" for everything in Home Assistant? Mine does that even though I can still get to the Keg Cop web GUI. If I reboot the ESP, then the data will show up again.....for a while (days? weeks? Haven't timed it).

 

[lagerbeer666]

Does yours ever stop communicating to HA via MQTT after an extended period of time and just show "Unavailable" for everything in Home Assistant? Mine does that even though I can still get to the Keg Cop web GUI. If I reboot the ESP, then the data will show up again.....for a while (days? weeks? Haven't timed it).

I mostly get disconnects from HA updating or me resetting the system after code updates.
I have to use the KC software reset to get MQTT to reset.

 

[MikeWhy]

Hi all

I have some parts I am looking to get rid of , as one lot not interested in selling off individual items. Couldn’t find an answer if selling is allowed within this forum area or if it needs to go in the for sale section, which. To be fair would make sense but the people likely to be interested will be reading this thread, anyway will pause there and if nobody complains will add more detail or move this off to another forum area

Cheers
Mike

 

[Exception13]

Hi all

I have some parts I am looking to get rid of , as one lot not interested in selling off individual items. Couldn’t find an answer if selling is allowed within this forum area or if it needs to go in the for sale section, which. To be fair would make sense but the people likely to be interested will be reading this thread, anyway will pause there and if nobody complains will add more detail or move this off to another forum area

Cheers
Mike

PM sent

 

[MikeWhy]

Ok so nobody told me off so far so will carry on , so in terms of parts we have

1 working system lolin d32 , with relay module , temp module and 4 flow sensors one of which is a brand new Swiss flow.
I was messing around with this one and trying to integrate into taplist.io but couldn’t get it working reliably at the time , things have moved on so no longer needed.

But of course it’s not easy or cost effective to buy the correct number of parts so there are enough parts to build another complete system with two sensors plus a load of other spares, connectors , basically everything shown in the pictures is included

This is all in the uk but it fits into a small package so can’t imagine posting worldwide would be a big problem.

Appreciate component prices change based on where you are in the world, but based on uk prices , import tax etc I would guess around £250 worth , have no idea what these are worth so just looking for a sensible offer

Cheers
Mike

 

[Lalo_uy]

Hi, very nice project.
Any one have tried with this kind of flow meters?
They have a propeller like inline, so not very convoluted path for the beer.

 

[LBussy]

The recommended flow meters, while expensive, do not promote much foaming. Some of the less expensive ones for “coffee makers” do create more. I have never used that one specifically.

 

[day_trippr]

The SwissFlow SF800 meters I've been using since 2014 have tiny rotors as well...

Cheers!

 

[LBussy]

They do, but they use infrared as a Hall effect sort of thing where the others I have seen myself had a physical counter. These may be great, just never used them.

 

[Lalo_uy]

I try the tourbine type some years ago for a bottle filler and the foam was disastrous.
The filler finally use an inox electrode to sense the beer in the bottle neck.
But these “in line” arived after that solution and never where tested.
The sensor is hall, with infrared you can “see” all 3 blades an have more accuracy.
Will give them a shoot. They are here, what to loose?

 

[LBussy]

All you have to lose is a few ounces of beer and a little time. What we get back is more info.

 

[DaveS]

I try the tourbine type some years ago for a bottle filler and the foam was disastrous.
The filler finally use an inox electrode to sense the beer in the bottle neck.
But these “in line” arived after that solution and never where tested.
The sensor is hall, with infrared you can “see” all 3 blades an have more accuracy.
Will give them a shoot. They are here, what to loose?

Please report back how well these work and a link to purchase if working well.
Cheers

 

[DuncB]

I've been using these with raspberry pints, positioned as close to ball lock connector as possible. I do use a 9.5 mm ( 3/8) to 8mm adapter after the flow meter.

I've used my counter pressure bottle filler as well direct off the taps and not had a foaming issue.
https://www.aliexpress.com/item/328...5e33c6d2&utparam-url=scene:search|query_from:

I tried the black meters that had half inch BSP connectors but they made the beer taste horrible.

 

[pers]

Not sure if this is a bug or how it's intended to work but ran into an interesting occurrence.

Forgot to make my taps inactive while running cleaner and sanitizer through them. One of the taps went pretty negative to almost -2 gallons. This tap completely disappeared from the home screen.

Going into the tap settings it showed as active. Selecting active/inactive and trying to apply seemed to do nothing. Finally realized that manually setting back to a non negative fixed everything and brought tap back to home screen.

 

[LBussy]

Not sure if this is a bug or how it's intended to work but ran into an interesting occurrence.

I am not sure what unintended there, but that’s what I would consider unexpected. Not necessarily the largest bug ever, but it likely should be addressed.

If you’ve ever done any work with these you probably know how perilous it is to go back later just for a small change. Libraries and especially core libraries move on and you are often left wishing you had ignored it.

 

[beren]

Might be as simple as making any negative numbers go to zero