Stc-1000+

[jleiii]

Initial indication tonight was no heat or cool. I changed the hy to 0.3, delays to 0, and it went into non-stop cooling mode. Since I want the temp to rise, not drop (only up 4.5F so far, but close to target of 12 in 48 hrs), I unplugged the pump. An hour later it's up almost another degree, and still in cooling mode, so I plugged the pump back in to see if it will stabilize. I suspect the ambient of almost 70F is causing it to rise faster than the ramp.

I looked at the current settings, using up and down arrows, and the current setpoint is 53F (same as start of ramp), and on PR1 step 0 for 1 hour. Hmm, 22 hrs in and on hour 1 still? Maybe changing the delays and hy restarted the profile?

Mats, will the up arrow current setpoint indication change (hourly?) as the ramp is running, or is it simply the starting point?

Edit - posted too soon. Now on hour 2, current setpoint is 53.8, so it's clearly changing, and the profile was obviously reset. So my Drest is delayed 1 day.

I had wanted to do a several day profile test run with water, but ran out of time with the lager as it's got to be done for a public event. Maybe it's not too late to get that test going anyway.... I have 5 STCs and 4 fermentation chambers, and the chiller is running anyway.

 

[alphaomega]

Mats, will the up arrow current setpoint indication change (hourly?) as the ramp is running, or is it simply the starting point?

It will show the current setpoint (and thusly be updated hourly when running a profile).

 

[Spellman]

Since it got reset you can always just punch in the current temp as your starting temp and estimate how many hours are left. It should work that way, I think I had to do something similar once when I was first using these and I accidentally restarted the profile.

 

[alphaomega]

Since it got reset you can always just punch in the current temp as your starting temp and estimate how many hours are left. It should work that way, I think I had to do something similar once when I was first using these and I accidentally restarted the profile.

Depends on what you mean here. Changing SP won't work, because it will be overwritten an the next one hour mark.
The better way would be to set St and dh (the counters for the currently running profiles step and the step duration), to 'jump' to the desired place in the profile. Possibly after that set SP to a sane value so it will try to maintain a sane value for the remainder of this hour.

 

[jleiii]

Depends on what you mean here. Changing SP won't work, because it will be overwritten an the next one hour mark.
The better way would be to set St and dh (the counters for the currently running profiles step and the step duration), to 'jump' to the desired place in the profile. Possibly after that set SP to a sane value so it will try to maintain a sane value for the remainder of this hour.

This makes sense. Is there a known trigger event(s) that restarts a running profile?

Had to run home at lunch, and it's .1 off the ramp point, and H&C are off. Same this morning. Looking good!

 

[alphaomega]

This makes sense. Is there a known trigger event(s) that restarts a running profile?

The way to restart a profile, would be to start the profile again (Set-rn-Prx). Changing other settings won't (or at least shouldn't), as mentioned you can jump in a running profile with St and dh, but that isn't exactly the same as restarting.

 

[Spellman]

Oops, yeah thats what I meant alphaomega. Thanks for correcting me! I think for simplicity (since I've never jumped into a profile), setting the st to current temp and estimating how much time you want left for the dh to finish out your ramp would be easiest, at least it was for me anyway!

 

[alphaomega]

Oops, yeah thats what I meant alphaomega. Thanks for correcting me! I think for simplicity (since I've never jumped into a profile), setting the st to current temp and estimating how much time you want left for the dh to finish out your ramp would be easiest, at least it was for me anyway!

St is the current step, so I guess you mean SP

 

[Spellman]

Sorry, currently landscaping in the hot sun, and stopping in for breaks. My mind must not be too sharp at the moment.

 

[alphaomega]

No worries @Spellman
You should move to sweden, you wouldn't be plagued by the sun

 

[jleiii]

The way to restart a profile, would be to start the profile again (Set-rn-Prx). Changing other settings won't (or at least shouldn't), as mentioned you can jump in a running profile with St and dh, but that isn't exactly the same as restarting.

As I was going through all the setting last night, I could have gone to a setting and 'entered' the same value vs 'returning'.
If I 'changed' the running profile or the ramp enable by going to it's value and then hitting S, have I effectively changed that value even though it was not actually changed, thereby starting new? I suspect this may be the case if so.

 

[alphaomega]

No, that should be ok also.

 

[ryannm]

My understanding is that the Arduino Uno should not be connected to the STC-1000 while the 120V AC power supply is connected to the unit. My question is which wires are problematic, i.e. must be disconnected. Must only the 5V and ground from the arduino be disconnected or must all of the arduino wires be disconnected from the STC-1000 board? In my build, I wanted to have the Arduino Uno mounted inside my box and permanently connected to the STC-1000 board. This way, in order to program the unit, all I need to do is attach a USB cable to my box. In order to avoid frying my build, I thought I might have (a) two two position DPDT switches with, (b) on one end, the 5V wire from the arduino and (c) on the other end, the 120V power supply to the STC-1000, and, (d) on the other switch I would have (e) the 120V neutral, and (f) the ground wire from the arduino. This would mean that, in order to supply power to the unit, I would have to disconnect the arduino, and, conversely, in order to connect the arduino, I would necessarily interrupt the 120V power supply, thus making it impossible to fry the unit. If, however, more than these two wires need to be disconnected from the arduino while the STC-1000 is powered with the 120V supply, then I would also need to add in some sort of a DIP switch or other mechanism to interrupt the remaining wires. Any input on this build plan would be greatly appreciated.

 

[smithabusa]

My understanding is that the Arduino Uno should not be connected to the STC-1000 while the 120V AC power supply is connected to the unit. My question is which wires are problematic, i.e. must be disconnected. Must only the 5V and ground from the arduino be disconnected or must all of the arduino wires be disconnected from the STC-1000 board? In my build, I wanted to have the Arduino Uno mounted inside my box and permanently connected to the STC-1000 board. This way, in order to program the unit, all I need to do is attach a USB cable to my box. In order to avoid frying my build, I thought I might have (a) two two position DPDT switches with, (b) on one end, the 5V wire from the arduino and (c) on the other end, the 120V power supply to the STC-1000, and, (d) on the other switch I would have (e) the 120V neutral, and (f) the ground wire from the arduino. This would mean that, in order to supply power to the unit, I would have to disconnect the arduino, and, conversely, in order to connect the arduino, I would necessarily interrupt the 120V power supply, thus making it impossible to fry the unit. If, however, more than these two wires need to be disconnected from the arduino while the STC-1000 is powered with the 120V supply, then I would also need to add in some sort of a DIP switch or other mechanism to interrupt the remaining wires. Any input on this build plan would be greatly appreciated.

ive actually connected both at the same time quite a number of times. No smoke yet I did it as a test as I knew someone would mistakenly do it on one of my pro controllers.

 

[Dunkderby]

I have also connected both many times without any issues

 

[smithabusa]

I must admit I was cringed up a bit when I first tried it waiting to see if a nuclear event was about to happen.

 

[alphaomega]

No problem keeping the arduino connected BUT you should only provide power from the USB or mains, not both at the same time. If you only intend to use the arduino to be able to reflash on occasion, then i suggest you place a diode between the arduino +5v and Vcc on the STC, so you don't 'back power' the arduino from the STC when running from mains.

 

[ryannm]

No problem keeping the arduino connected BUT you should only provide power from the USB or mains, not both at the same time. If you only intend to use the arduino to be able to reflash on occasion, then i suggest you place a diode between the arduino +5v and Vcc on the STC, so you don't 'back power' the arduino from the STC when running from mains.

Great, thank you all very much for your help - this is great news. It sounds like building it in the way I am suggesting is unnecessary, but is a way to make it foolproof such that not even a particularly determined fool can ruin my build without opening it and rewiring it first.

 

[sasky7777]

I am attempting to flash with the arduino pro mini and the CP2102. The Github instructions tell me to remove the 3.3V pin but I have 5V, CTS, the lastly GND where as the instructions show 5V, GND, 3V3. Which pin do I remove?View attachment ImageUploadedByHome Brew1438637934.395088.jpgView attachment ImageUploadedByHome Brew1438637947.912201.jpg

 

[alphaomega]

I've not seen these 2102 boards myself, so I can't answer definitively.
I would think you don't need to remove any pin, but if you do, CTS would be my bet. @TrippleHopped had the same question, but I don't think I heard back from him how it turned out.
Please post any findings
Cheers!

Edit: woo hoo! Post #2000!!!

 

[wbarber69]

Just bend back the pins that don't match up on each board and you should be good. So usually dts rx tx 5v gnd get connected. grn is actually a reset pin and dts is also a reset pin. These need to be attached so when you upload a sketch the arduino will reset for the programmer to begin.

 

[sasky7777]

I didn't take out any pins and just hooked it up. I can't solder electronics worth a damn but somehow got enough in there and didn't fry the board. My biggest issue was drivers. I couldn't get Arduino to recognize anything but Bluetooth ports on my Mac OSX. Went to the Arduino forum and got the link to CP2102 drivers. Search CP2102 driver and go to the silabs.com address. I had to switch USB ports and do some restarting but I finally got it to work. Best sound of the last 16 hours was that buzzing sound as the sketch uploaded

 

[sasky7777]

Last follow up to the flashing, I found it much easier not to remove the solder from the STC board and just press the pins from the Arduino to it. I got the best connection on the bottom of the STC, and found there wasn't any advantage to having pins permanently attached to the STC.

 

[Jakor]

EDIT: Duplicate post

 

[Jakor]

I recently got a mini fridge set up with an STC-1000 (Lerway from Amazon), and it just so happened to be the AG_400P v1.1 model!

I immediately ordered the Arduino mini and usb so I can flash mine, but that got me thinking on what to do with this Arduino after this project. None of the current projects out there really interest me, but I found this thread: https://www.homebrewtalk.com/showthread.php?t=517849

Based on what I've read about alcohol sensors, I can't find any solid info on the accuracy or precision of these sensors, but could we somehow use this type of a monitor to output a signal to the STC, allowing it to trigger temperature ramping once a certain percent of attenuation is reached? Additionally, the arduino component could transmit the data over bluetooth or WiFi.

Even more simplified, could one hook the alcohol sensor up to the connections for a second temperature probe, and have the STC could interpret the resistance of this sensor to know when to change temperature setpoints? Based on what I've read on the GitHub page, the processing power of an STC seems fairly limited, so I was wondering if anyone would have any input on the feasibility of this feature. I would be interested in looking into developing this myself, but my programming knowledge is limited, and so I'd like to ask those more experienced before digging too deep.


My second idea for this project, which would probably be much more simple, is custom temperature probe lookup tables. Would this be as simple as digging through the source code, and replacing old numbers with the values I find from another manufacturer? My reasoning behind this is if my probe were to ever get damaged, I could simply buy any RTD, Thermocouple, or Thermistor depending on the uncertainty I would like or amount I want to spend and simply replace the lookup table to match my new sensor.


I would appreciate any input on either of these ideas!

 

[alphaomega]

I recently got a mini fridge set up with an STC-1000 (Lerway from Amazon), and it just so happened to be the AG_400P v1.1 model!

I immediately ordered the Arduino mini and usb so I can flash mine, but that got me thinking on what to do with this Arduino after this project. None of the current projects out there really interest me, but I found this thread: https://www.homebrewtalk.com/showthread.php?t=517849

Based on what I've read about alcohol sensors, I can't find any solid info on the accuracy or precision of these sensors, but could we somehow use this type of a monitor to output a signal to the STC, allowing it to trigger temperature ramping once a certain percent of attenuation is reached? Additionally, the arduino component could transmit the data over bluetooth or WiFi.

Even more simplified, could one hook the alcohol sensor up to the connections for a second temperature probe, and have the STC could interpret the resistance of this sensor to know when to change temperature setpoints? Based on what I've read on the GitHub page, the processing power of an STC seems fairly limited, so I was wondering if anyone would have any input on the feasibility of this feature. I would be interested in looking into developing this myself, but my programming knowledge is limited, and so I'd like to ask those more experienced before digging too deep.


My second idea for this project, which would probably be much more simple, is custom temperature probe lookup tables. Would this be as simple as digging through the source code, and replacing old numbers with the values I find from another manufacturer? My reasoning behind this is if my probe were to ever get damaged, I could simply buy any RTD, Thermocouple, or Thermistor depending on the uncertainty I would like or amount I want to spend and simply replace the lookup table to match my new sensor.


I would appreciate any input on either of these ideas!

Congrats on getting a 'good' unit!
I'll try to address your questions.

I have no experience in alcohol sensors myself, but I'm under the impression that they are no good for monitoring fermentation (and I think that it would be well known by now if they were, considering the efforts that go into this).
I think you would be better off with a simple photo interrupter attached to the vapor lock. That way you will receive an interrupt on the microcontroller each time a bubble passes, a very simple solution.

Now I know some people claim that bubbling has nothing to do with fermentation, but I think that is just hogwash. Of course it does, fermentation produces massive amounts of CO2. BUT, one needs remember that 1) bubbling does not equate to active fermentation (off gassing, temperature fluctuations et.c. can cause this) and 2) lack of bubbling does not equate to lack of fermentation (leaky seal for instance).
However, I think the rate of bubbling can be related to the rate of fermentation, so this can be used as an input to control a raise in temperature as fermentation slows down. You just need to be careful and have some sanity checks along the way.

I think you'd probably want to start by using the communication firmware (and sketch) and hook up your arduino to be able to talk to the STC. Hook up the other sensors and wifi/bluetooth and whatnot to the arduino, and possibly adjust the profile from the arduino if/when needed based on the data. Coding for the STC (while C) is an art form and even if you are an experienced embedded developer, you'll have a bit of of a learning curve before being productive. And even then you will be severely restricted in what you can do, as the MCU is truly tiny and pretty much all of it is in use already by STC-1000+.

You can change the look up table (and recompile) to accomodate other sensors. But unless it is another 10k NTC sensor, you'll need to modify and/or add hardware to turn the signal into an analog value in the 0 to 5v range that the MCU needs.

Cheers!

 

[schmartz]

Why not just use a pressure transducer and a float that's slightly denser than wort hanging in the wort? The weight would increase slightly as the fermentation proceeds and it would be pretty accurate.

 

[alphaomega]

Why not just use a pressure transducer and a float that's slightly denser than wort hanging in the wort? The weight would increase slightly as the fermentation proceeds and it would be pretty accurate.

A pressure transducer measures the pressure in a gas (or liquid), so that will be difficult to tie a string to... I'm guessing you want to use a strain guage instead.
Still, this has several problems. Finding/building a suitable weight, keeping said weight +string sanitized, attaching to the strain guage and somehow pass through the lid of the fermenter in a sanitary way.
After that you just need to worry about CO2, krausen and drift of the strain guage to mess with the measurements, before you're done.
That's why you don't just do that.
Not saying it can't be done (it even has been done with the beer bug I think), I'm saying it is not all that easy and probably more trouble than the reward.

 

[Jakor]

Yeah I like the idea of a strain gauge, but it looks like a more expensive route. Working with a voltage divider would make it really easy, assuming the stc can handle it. Alpha, do you know what voltage is applied across the probe terminals? I looked into possibly a weight that was just buoyant at an SG of 1.030. That way, when it sinks, it pulls down on a sensor or gauge. In the end it's probably just more reliable to put a scale at the bottom of the charger, and not mess with putting anything else in your carboy...

 

[alphaomega]

Yeah I like the idea of a strain gauge, but it looks like a more expensive route. Working with a voltage divider would make it really easy, assuming the stc can handle it. Alpha, do you know what voltage is applied across the probe terminals? I looked into possibly a weight that was just buoyant at an SG of 1.030. That way, when it sinks, it pulls down on a sensor or gauge. In the end it's probably just more reliable to put a scale at the bottom of the charger, and not mess with putting anything else in your carboy...

Strain gauges (and instrumentation amplifiers) can be bought pretty cheaply on eBay. But still, I think over time drift may be a problem.
I guess there are people who take their beer making a lot more serious than me, considering the efforts that go into continuous SG readings. I just don't care that much. Pitching an active culture at an appropriate temperature, I just trust my 'yeastie boys' to do their thing and so far it's been working out quite nicely
Now, if someone comes up with a simple-ish, cheap-ish, none invasive method of measuring SG continuously that works reliably, then that would be really cool and I'd definately look into it, but until then, I'm not losing any sleep over it