Stc-1000+

I turned the setting screw on the wine fridge to the lowest setting. I put the probe in a water bottle like this one:



Here are two pictures of my setup.




For now I set the hysteresis at 1°F to force a longer cycle time, but I'm going to swap out the STC-1000+ and reflash the unit to see if I can get the delay to work again.

 

Not a Bug Report

Follow-up to my post here:
I can confirm that the cooling delay and heating delay settings don't appear to have any effect in the STC-1000+ firmware. I have just tested my new unit and set both delays to 10 minutes manually. Despite these settings, both heating and cooling outlets are (individually) activated after about 55 seconds.

See explanation of cooling/heating delay below:
http://www.homebrewtalk.com/f51/stc-1000-a-464348/index141.html#post6462932

 

Thank you St. Pug. For now I'll set the hysteresis to lengthen the cycle time. I have to check out the one in my keezer too.

 

Thanks!
I'll be sure to include the autocomplete='off' as soon as get the chance then.
I'm glad you're ok with the changes I made as well. I don't want to upset anyone, especially anyone that contributes code
Thanks for your effort on this. I'll be sure to add your name to the preamble as well!

This is the initial heating/cooling delay. It is always approx 1 minute. This is documented (at least I think it is, otherwise it should be).
After that the cooling delay should be the selected value. The reason being that on fluctuations in power supply (ie outage), you don't want rapid compressor cycling even if delay is set to zero. In the same manner if you have the delay set at half an hour, you want it to turn on faster than that initially when you first plug it in. The initial one minute is the tradeoff made.
If cooling/heating delay don't work as expected after the first cycle, then it is a bug or an error somewhere else. I haven't had any bugreports on this, but that does not mean that it can't be a bug, might just be no one has caught it yet.

 

Alpha,

The cooling delay doesn't work as expected after the first cycle for me:

I have an STC-1000+ running a closet, in "th" mode set to 55°F with 0.5°F hysteresis and a 20 minute cooling delay. I have the temperature probe in a 1/2 liter bottle of water. It is cycling every 5 minutes or so. I don't get the blinking cooling light, it just switches on, turning on the compressor on the wine fridge unit I have. I think the STC-1000+ is ignoring the cooling delay. I don't understand why. For now I have uped the hysteresis to 1°F, but I'm thinking I should take out the STC and re-flash it. I also have a spare I could swap out. But I figured I'd ask to see if anyone knew what else I could be doing wrong.

 

I am always happy to help where and when I can. This project takes what was a simple but effective basic device to a much higher advanced level. Thanks for your hard work and time, and for sharing with us all. Cheers!

Thank you for explaining this, and you are absolutely correct. The initial 1 minute delay is just experienced when initially powering on the device, afterwards the user set delay is adhered to (in my case 10 minutes). Thanks for clarifying this point. Once you explained it, this was easy enough for me to test by picking a cooler than ambient set temp; waiting the minute for the cooling relay to turn on; put probe in ice water to reach set temp and deactivate cooling relay; pull probe and warm up in hand to initiate user set cooling delay.

 

Yeah, it is hard to tell what is wrong here. What version are you running?
Flashing it again could be a good idea. Trying another unit could also be a good idea.
It sounds much like a software issue, but it is hard to say what the cause could be.

Thanks!
This would also suggest that the issue satph is having isn't a software bug per se, but something else is wonky with that unit. Again a new upload might be the first attempt at correcting the issue.

 

I just used my STC for the first time. It's temp control was on point.
One problem: I did not think to tape the thermometer to the bucket. I had it set to 63, but the sticky thermometer on the bucket read 70...
**** balls.

 

I'm using 1.05. I have the problem with two different units. I re-flashed the unit and still have the problem.
Let's say the water is 57°. I set the STC to 55° and get it to start cooling, it usually takes about a minute to turn on. Then I raise the set point to 57° to get the STC to shut off. If I lower the STC to 55°, it starts cooling again within a few minutes (I've timed 1:30 and 3 minutes). I have the cd set to 20 minutes. I can make the hysteresis larger to mitigate the issue, but I don't think it should be operating this way.

 

Okay, this is quite similar to my setup. Instead of a water bottle, I use a wine bottle willed with water with a thermowell inserted through the cork. The mechanical thermostat cycles pretty frequently and I'm hoping to reduce the amount of cycling by giving it larger hysteresis. I've had it running for a couple of months, but need to put more of my wine into it, which should also reduce cycling (due to thermal capacitance of all the bottles in there).

 

I set up an STC flashed to 1.05 on a test rig. I set the cd to 20 and the sp to above ambient and waited for the cooling to come on. I then cooled the probe with an ice cube to get it to shut off. I then warmed the probe in my hand, and the cooling went to delay, but came on within 3 minutes the first time, and 1 minute the second time I did this test. I can upgrade to 1.06 and try again. I would think the cd setting should override everything else, or do I have something else set incorrectly?

 

FYI, these units have arrived (dual-sensor capable from the factory) and are now available flashed here. No mods required for the dual-sensor firmware, these will come to you flashed and ready to install with the 2 sensors included.

Thanks,
Will

 

The underlined part of the bold sentence above should be 'below' in order to activate the cooling relay, OR you would have needed to warm up the probe in your hand at this point to move the current probe temp above the setpoint. Perhaps this was just a typo or omission in your post? If not, then it should have been your heating relay that was activated since the STC would want to move your current temperature upto the 'above ambient' setpoint temperature.

Making sure both delays are set to 20 minutes would ensure that regardless of which relay is to be activated, it should take 20 minutes for it to activate.

I just tested mine again to see how the delay timing compares to what it should be because earlier I noted that the initial minute delay seemed a bit faster than a minute. What I'm seeing is that activation of the (cooling) relay is happening at ~93.5% of the total time (haven't tested heating relay). Generally speaking, this is a non-issue BUT it could account for nearly 16 hours early step-change on a 10 day interval if it always takes place at ~93.5% of the way through the current step. Here are the notes I wrote down:

Like I said, I can't really think that this would be an issue at any point during a fermentation since we are generally aiming for step changes to take place well after a phase of fermentation has ceased but I thought I'd mention my observation. It may just be a limitation of the STC. Regardless, I'm not worried about it

 

St. Pug, you are correct I meant below to activate the cooling relay. I set the delay to 60 minutes, and it's still cycling within a minute or two. I'm getting this on multiple STC's with the 1.05 and 1.06 versions. I can over come it with a larger hysteresis, but I can't get it anywhere near the specified time.

 

I'll have to defer to someone more knowledgeable than me for this one. It certainly sounds like your units are not accounting for the delay correctly.

The only thing I can think of is that you're not 'saving' the delay when setting it, but this would be obvious by simply checking out the [cd] and [hd] settings and they were defaulted to '2' again.

 

This is due to how I needed to select the timer for counting 'real time'. 1 second is actually 960ms (theoretically) and I haven't bothered to adjust for delay counters.
However, counting hours does take account for this and should be as accurate as possible with the internal oscillator of the PIC.

Yeah, I don't know either what the issue could be. I don't really think it is software, as StPug verified the behaviour.

 

Problem solved!

I think the sketch I was using was damaged. I deleted my picproj and downloaded the latest version. Most importantly, pressed the upload button on the Arduino software to upload the new sketch to my Uno. I wasn’t pressing the upload button, so I think I was uploading the same damaged sketch each time. I now have 1.06 running, and it just waited the 20 minutes to cool.

Thanks again AlphaOmega for this great software, Will for his videos and providing flashable units, and to St. Pug for testing my problem.

 

Nice to hear you got it sorted!
And yes, if you really must upload the sketch to the Arduino, otherwise the same (old) sketch will run.
Again, really good to hear things got sorted

Cheers!

 

Just curious about where to get the dual sensor STC-1000 in Europe, as Will Conrad doesn't ship accross the pond?

Cheers

Drio

 

I don't mind shipping international but assume you need the 220v version though correct?

 

Sorry if this has been asked already. I just got my Arduino Pro Mini and CP2102 and the USB module is slightly different from the user manual.

CP2102 has:
DTR
RXD
TXD
5V
CTS
GND

Pro mini has:
DTR
TXO
RXI
VCC
GND
GND

Do I remove the CTS pin and then solder the following?
DTR to DTR
RXD to TXO
TXD to RXI
5V to VCC
GND to GND

 

That sounds correct to me. But if you can, try it before you do anything permanent.

 

Thank you. This worked great and I got it flashed and all boxed up. Just in time for my 2 day old lager, on which I'm trying the brulosopher quick lager profile. Keep up the good work and thanks again.

 

These seam to have a Jtag connection for programming; I suspect the G80F910D is a kind of Atmel clone/variant/re-branded/Oem version of an existing MCU.

A datasheet is here.

http://www.dycmcu.com/index.php/view-212.html

 

AlphaOmega, would it be possible to make one temperature probe seek to match the other in the 2 probe system?? I would like to use it to control a kegerator tower cooler, and would like the tower cooler to turn on when the tower probe temp raises about a degree or half a degree above the probe down in the kegerator itself, to keep them as close to the same temp as possible. I could leave the cooler on 24-7, but besides wasting electricity and burning out the motor, the motor running constantly produces heat that would also cause the kegerator compressor to run more often as well, wasting more electricity and wear and tear. Trying to control it by not having one probe match the other seems like a fools errand if you don't want to just keep the tower cooler on 24 7. Do you think it would work?

 

It depends on your definition of possible. It is not possible with (nor within the scope of) the STC-1000+ firmware, so you'd have to do some coding yourself to have that functionality.

 

Awesome, sounds good, thanks!

 

I'm still in process of wiring up my first STC-1000+ controller with 2 thermisters but thought I would share a couple things. I didn't think too much about it when I ordered my three pin connectors for the board, but when they arrived they were about half the size I needed. What you want is 5mm pitch, not 2.54. At least they were cheap!
I also got a bunch of 10K ohm 1/4W resistors like these (not the SMD ones) as 200 was about the same as buying ten. If anyone needs some just shoot me your address and how many you need. Also, if anyone needs some 2.54mm pitch 3 pin connectors for another project, let me know.

 

I upgraded my Ranco two-stage controller for one of wilconrad’s early black boxes in order to add profiling capability to my fermentation. While the profiling was a desired improvement, I had concerns that excessive ping-ponging of temperature during fermentation might trigger premature hibernation of highly flocculate yeast strains. In particular, I experienced such issues with WLP007, but could not be certain that the temperature ping-ponging was the culprit. So, when wilconrad made available an STC1000+ with two probes and alphaomega’s version 1.06, I jump on it and upgraded my controller. For the last week, I’ve been testing the two probe black box with a beerbug. The beerbug allows me to record both external ambient temperatures and internal wort temperatures via a thermowell. Both the STC and the beerbug probes are in a thermowell. The STC secondary probe measures the air temperature outside the wort. The attached graph shows the STC regulating with and without aid of the second probe.

 

Without knowing more about your setup, it is hard to speculate what is going on.

I'm assuming you are using a refrigerator or freezer? What are you using to heat? What are your settings on the stc? I have been successfully keeping my fermentations within .3 or .4 F of my set point with ease and consistency. Most of the time it spends much closer, but I get a bit of undershoot temps with my glycol chiller. Back when I had less aggressive cooling capabilities I was within .1-.2. It looks like you have got some swings greater than should be towards the beginning, and very large at the end. If you give us some more details we should be able to get things sorted out for you.

 

Spellman, thank you for your thoughtful reply, but my post was not to ask for assistance in diagnosing an issue as much as to report the positive effect of the second probe and release 1.06. You'll notice that when the second probe is disabled, the temperature oscillation of around 2 deg. where as with the second probe, the internal temperature is far more stable.

Jim

 

Thanks for sharing your experience with the second probe!
Awesome to see it in action

 

ive personally had really good luck with temp probe sandwiched in some papertowel folded up taped to the side of the ale pale. I am not logging, but whenever I walk by it I am always extremely close to the setpoint, I don't ever see it cycle back and forth between heat and cool. Its typically cycling just heat and off, or just cool and off. Using a 1 degree hysteresis.

Greg

 

Thank you Jaw. Would be interesting to see a comparable chart using only one probe, with the probe taped to the side of the fermenter with a little insulation -- but leave the beerbug in the thermowell. The lesson may be that one probe taped to the side is okay, but if you want to use a thermowell, you need two probes.

If you are so generous to conduct this experiment, please also let us know what you are using for a fermenter.

 

doug293cz, the STC1000+ probe was in a thermowell in the center of a carboy filled with water. I believe your theory is correct and seems to be collaborated by Greg's observations that putting a single probe on the exterior surface in the absence of a second probe would be better. Actually, in an offline exchange with wilconrad, he suggested the same. But, I was intrigued with the idea of two sensors, and glad that it seems to work well. I would love to test the theory of putting a single probe on the exterior carboy surface, but I plan to brew this weekend and want to use both probes.

Jim

 

I'm a little late to the party on this, but would love to use the HEX Editor to keep all my units the same and up to date. I make a lot of changes to profiles, so this is a great tool. Thanks guys!

Question: Do I need to start from the editor's default values each time, or is there a way to save my profiles in the editor? Or, is there a way to easily import/paste in values from a spreadsheet? I think this may have been asked, and there was a response about using a cookie. Could someone explain the recommended procedure a little more? Would be much appreciated!

 

I guess if your controllers are in a situation that's makes them easy to flash then using this generated HEX to quickly update fermentation profiles might be reasonable, otherwise I find it easiest to use this when initially flashing the hardware and then making manual adjustments from there. I find that I'm usually changing an individual duration or temperature, but rarely an entire profile.

Regardless, as it stands now, you have to start from default/base values each time. However, if you simply download the html, javascript, and css files and store them in a directory on your computer then you can manually change the default values in the html file and save your changes. Then simply drag-and-drop that html file into a browser to open it with your new values. The files you would need are:

https://04377c9983bdba740a8b0c997fe...t/0B7OSUyUx3xJzUVlLdkFyQ1lMLTg/hextabbed.html
https://04377c9983bdba740a8b0c997fe...B7OSUyUx3xJzUVlLdkFyQ1lMLTg/jquery-ui.min.css
https://04377c9983bdba740a8b0c997fe...0B7OSUyUx3xJzUVlLdkFyQ1lMLTg/jquery-ui.min.js
https://04377c9983bdba740a8b0c997fe...st/0B7OSUyUx3xJzUVlLdkFyQ1lMLTg/jquery.min.js
https://04377c9983bdba740a8b0c997fe...7OSUyUx3xJzUVlLdkFyQ1lMLTg/jquery.flot.min.js

Hope this helps!

 

alpha, yesterday I was moving forward a step in a fermentation profile and thought how easy it would be to simply perform a button push action to move forward (backward too maybe). Say for instance I want to move forward from SP0 to SP1, I could simply double-press a certain button. Or, move from SP0 to SP2, I could simply double-press, twice. I'm sure this is a bad idea and I just need you to show me why