Curing Chamber Development

[TrickyDick]

Howdy,

Nice project for the dry cure chamber. I've been wanting to build one based on a compressor refrigerator. The one I picked up however was a side by side, and I determined it would be bad to use one that style. I've wanted to do a freezer on bottom type curing chamber but have been unable to locate an affordable fridge. Your mini fridge option looks like a great idea. I am primarily interested in making dry cured and fermented sausages and possibly some smoked items. As well. I have a bradley smoke generator and cold smoke adapter unit that I had previously purchased. I am curious what dcarch uses for cold smoke, and how the smoker is use indoors! Also would love to see pics especially of the light for heat and how the temp output from that bulb is controlled.

I am also not sure what a PowerSwitch tail is.

How many pounds of sausages could you hang in that fridge? Would crowding pose a problem?

How did you cut the bottom of the fridge out without hitting coils? What brand and model fridge are you using?

One of my other hobbies by the way is homebrewing, and there is a need to control fermentation temps. Some folks have taken a STC-1000 temp controller and reprogrammed it (using an arduino) to achieve a variety of preset values. You are using the arduino directly to control the process it seems.

I've already bought all the gear that I thought I'd need to convert a fridge based on an STC-1000 temp controller, and an inexpensive humidity controller with a ultrasonic humidifier, and a couple of computer case fans. I may need to rethink. The ability to monitor the temp and RH over time I would think to be valuable. In Florida, it's mostly very high RH year round.

Thanks for sharing.

[Chris Hennes]

Info on the PowerSwitch tail here. Crowding can pose a problem if you have inadequate airflow or no good way to reduce the humidity in the chamber. In my climate the fan works very well as a dehumidifier, but that may not be true for you. I don't yet know the full capacity of the fridge, I've only got about 4kg of product curing right now. I am hoping to be able to do nine soppressata at a time in this installation, but won't know how well that works for a while yet, I've got other projects lined up before it. This fridge has coils in the sides, but not the bottom, so cutting out the bottom was no big deal. It's a Danby Designer DAR044A1BDD Compact All Refrigerator, 4.4 Cubic Feet. 

[TrickyDick]

I'll look into those links. Thanks! Since I'm not a programmer like you, is there any chance you'll be able to share the coding details or a walk through on how to make our own similar device? I wish I knew more about this kind of stuff. I already have too many hobbies, and learning to program is not one I'd want to add to the list however. It would only be to the point to get a final operational controller. I may end up wanting to build a setup on a cart so I could roll it outside of i wanted to setup with a cold or hot smoking capability. The link to the refrigerator is not working for me by the way.

Edited January 12, 2015 by TrickyDick (log)

[Chris Hennes]

The control code is available at github.

[TrickyDick]

That is basically my setup, a 4.5 cu. ft. refrigerator converted.

Except mine is also an indoor smoker, using an external cold smoke generator. Heat for smoking is actually a 500 watt halogen bulb dimmed to 300 watts. It can get temperature to 200F for smoking. Any higher may melt the plastic interior.

Moisture is added using an ultrasonic humidifier.

dcarch

[TrickyDick]

Chris, I'm pulling the trigger on building one of these for myself. I am going to skip the cold smoke option initially ( not super happy with the bradley for a cold smoke generator, plus could always smoke in my smoker. ) Parts questions for you. What AC relays for the lamp and humidifier? What LCD panel? I have a breadboard and jumper wires already. Any further updates on your project?

[Chris Hennes]

The AC relay is a PowerSwitch Tail (I bought the kit version because it's cheaper). I have no idea which LCD panel I used, it's a generic 16x2 I had laying around. The temperature and humidity control is very well dialed in now, I was really happy with the performance over the last couple months. The long-term averages are basically exactly on my targets.

[TrickyDick]

Thanks. I have parts on order. Do you have a wiring diagram and a transistor ID? Are you using three PowerSwitch tail for the three devices: fridge, lamp, and humidifier? Have you implemented the lamp yet? I might begin fiddling with initial assembly this weekend, but seems that building the cabinet should probably be first thing I start with.

[Chris Hennes]

No wiring diagram, it wasn't complicated enough to bother with. I've just got two Tails right now, I don't have a heat lamp installed at the moment, and the dehumidification is just a CPU fan so I didn't need one for that. The transistor is an IRF520 I had laying around, it's not controlling a whole lot of power so you could probably any just about anything. 

[TrickyDick]

Thanks. I'm pretty rusty in the electronics realm. Had a couple courses in high school eons ago. We built an AM radio I recall. Got a basic book on programming arduino from Amazon when ordering the other stuff. Got a small relay that claims can operate up to 250VAC/10A for under $10. Might try using that instead of another tail, which is pricey by comparison. That said, I don't think I really trust the tiny relays to operate say a mini fridge, for which I will be using a PowerSwitch tail. Pretty cool device actually.

What are you using for temperature control, or are you only trying to monitor and regulate the humidity? I have a STC-1000 which comes with its own temp probe that I had originally planned to use with a separate humidity controller like what had been discussed earlier in this thread.

I definitely want to be able to control the temp to conduct sausage fermentations. Considering that others had used halogen lamps (I think the stated a 300 or 500 watt lamp, but I think that's a typo?). I'm wondering if a regular lightbulb or even reptile heating cord would be an option.

No progress so far. Need to get a cabinet built. You are using a different PC case fan at the bottom of your fridge/cabinet interface? Any sealant or lining in that cabinet by the way??

[TrickyDick]

I have my cabinet, and now ready to begin!!!

[TrickyDick]

Ok I began today. So far I have the base cabinet and fridge with holes drilled and a PC case fan mounted between the top of the cabinet and the bottom of the fridge, friction fit, and semi-screwed into place (eventually I'll use bolts).  I have some L-brackets mounting the fridge to the cabinet which has mounted casters, to keep fridge from moving.

 

I need to find a dummy guide for how to use and connect the Arduino controller to other stuff (humidity / temp sensor, LCD display, Relay, powerswitch tail, etc...)  I have the Github code downloaded and beyond that, I am pretty much clueless as far as the controller.  I have a breadbord and some connectors that I bought for a different project I was working on, but I don't really understand how the breadboard "works" either.  Time to reach out for help and do some looking online...

 

TD

[Chris Hennes]

Here's a great article on breadboards:

https://learn.sparkfun.com/tutorials/how-to-use-a-breadboard

 

And to get started with Arduino, you might check out this guide:

https://learn.sparkfun.com/tutorials/sik-experiment-guide-for-arduino---v32?_ga=1.75953877.1118589479.1398115576

[dcarch]

What brand cold smoke generator are you using?

I cannot seem to find any 500 watt halogen bulbs. What bulb are you using?

TD

Home made cold smoke generator.

 

These halogen bulbs. Very easy to find. I think HD has them also.

 

http://www.harborfreight.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/i/m/image_12990.jpg

 

dcarch

[TrickyDick]

Here's a great article on breadboards:

https://learn.sparkfun.com/tutorials/how-to-use-a-breadboard

 

And to get started with Arduino, you might check out this guide:

https://learn.sparkfun.com/tutorials/sik-experiment-guide-for-arduino---v32?_ga=1.75953877.1118589479.1398115576

Appreciate it!  I got the board plugged into my laptop and fiddling with it.  I tried to upload your code but received an error message that it could not find the file or folder dht.h (or something along those lines..)

 

I think that its going to take some time for me to figure this all out, but looks to be like its well worthwhile.  Appreciate the work you've done on this and hope to be making some fermented dry cured sausage soon!

 

TD

[TrickyDick]

Home made cold smoke generator.

 

These halogen bulbs. Very easy to find. I think HD has them also.

 

http://www.harborfreight.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/i/m/image_12990.jpg

 

dcarch

Hey thanks a bunch!!   Would love to see the details on that home made Cold Smoke Generator!

As far as those halogens , how do you have them mounted?  How many bulbs are you using and in how large of a chamber?  I am wondering if I'll need more than one.   Are you using a dimmer too? The link and a search on harbor freight shows those to be replacement bulbs for an existing light/lamp?  Seems to get low marks from the reviewers.  Have you had good luck with them lasting through a fermentation?  I probably don't need much heat here in FL.   I definitely need a heat source in my chamber as I intend to do fermented sausages.

 

Another dumb question for anyone.  Arduino pulls power from the USB port on the computer, but once programmed and not connected to a computer, what voltage does it require?  I bought a wallwart type power supply that's 9 volts 650mAh.  Is that too much?  Isn't USB 5 volts?

 

Some other thoughts for anyone to comment please.  From the looks of it, I'll have 4 devices operated by the Arduino:  fridge, heater (halogen lamp), humidifier (and lower fan possibly), plus dehumidifier (upper exhaust fan(s)).  Is there even a fan in use in the lower cut-out hole or is it just an open passage on the one Chris built?  Seems the small exhaust fans and probably intake fan if one is needed, could be controlled by Arduino itself, but the others - humidifier and lights take AC power.  I got this little board that I'm hoping to use to control those via the digital output pins to actuate AC relays.  The documentation is non-existent on the relay board.    The LCD panel I got has a daughter board hooked up with GND VCC SDA SCL connections (This is similar to the LED boards for the BCS-460 controller).  I'm thinking that those could be used to connect the LCD board instead of the 16 pin bus?

 

Well, getting late here, and my head is spinning with information overload.  Time for bed!

TD

Edited April 12, 2015 by TrickyDick (log)

[dcarch]

Hey thanks a bunch!!   Would love to see the details on that home made Cold Smoke Generator!

As far as those halogens , how do you have them mounted?  How many bulbs are you using and in how large of a chamber?  I am wondering if I'll need more than one.   Are you using a dimmer too? The link and a search on harbor freight shows those to be replacement bulbs for an existing light/lamp?  Seems to get low marks from the reviewers.  Have you had good luck with them lasting through a fermentation?  I probably don't need much heat here in FL.   I definitely need a heat source in my chamber as I intend to do fermented sausages.

 

--------------------

TD

 

Start a new thread. I will answer your questions. 

 

Don't want to hijack this thread.

 

dcarch

[Chris Hennes]

Comments in-line for convenience...

 

Another dumb question for anyone.  Arduino pulls power from the USB port on the computer, but once programmed and not connected to a computer, what voltage does it require?  I bought a wallwart type power supply that's 9 volts 650mAh.  Is that too much?  Isn't USB 5 volts?

The Arduino has power regulation built into it, 9V will be fine.

 

Some other thoughts for anyone to comment please.  From the looks of it, I'll have 4 devices operated by the Arduino:  fridge, heater (halogen lamp), humidifier (and lower fan possibly), plus dehumidifier (upper exhaust fan(s)).  Is there even a fan in use in the lower cut-out hole or is it just an open passage on the one Chris built? 

No fan at the bottom, that's the humidifier inlet, a fan in the direct path of the mist would probably not last long.

 

Seems the small exhaust fans and probably intake fan if one is needed, could be controlled by Arduino itself, but the others - humidifier and lights take AC power.  I got this little board that I'm hoping to use to control those via the digital output pins to actuate AC relays.  The documentation is non-existent on the relay board.    The LCD panel I got has a daughter board hooked up with GND VCC SDA SCL connections (This is similar to the LED boards for the BCS-460 controller).  I'm thinking that those could be used to connect the LCD board instead of the 16 pin bus?

Relays are pretty simple: in general you just apply power and the switch flips. If your LCD panel is controlled using I2C (based on the inclusion of the SDA and SCL lines) you can use the Wire library to communicate with it. You will need the documentation for the controller chip to figure out how.

[TrickyDick]

There is of course no documentation with the LCD I bought, but there are some folks on amazon that have bought and have given help on how to get it working which I hope will work for me too.  I think that some of the issues relate to findhing the correct serial address.  Next will be how to modify your code to work with the LCD and display the right, but that's still a long way off for me.

I'm still fairly intimidated by the programming, especially after reading the PDF on the temp/humidity controller.  Mostly having an issue with the libraries and directory structure to get it all compiled and uploaded.  I'll probably end up asking a few friends for some help with that at some point if (more like when) I get stuck.  Appreciate the help you've given me here!  I will be wanting to setup the heater/lamps and humidification in addition to the cooling(fridge) and dehumidification (fan) from the start, so that'll entail more fiddling with your code.

 

Can I ask how many fans did you install in the top of the fridge chamber?  Any coolant lines running in the top part of the fridge to avoid (I got the same model you are using)?  Are you bringing the wiring through into the chamber via any additional holes or piggybacking those through the top fan hole(s) and lower humidifier hole?  How are you displaying the humidity and temp graphs like you had posted earlier?

 

Looking forward to using this creation soon!

 

TD

[Chris Hennes]

Yeah, the mess of that Arduino code is my fault: I prefer to work from a command line interface, which the baseline Arduino IDE does not provide. So I used one someone else had rolled together, and it's not actually very good. If I was you I would just pull the source files out of the directory structure I set up and create a new, normal Arduino sketch.

 

I've only got one fan, I didn't see any reason to add more. Right now things are still in prototype stage, so the sensor wire is simply run through the fridge door. Everything else is outside the refrigerator compartment. I cut my fan hole off-center to make sure I avoided anything that might be in the way of the hole. There are no coils up there, so it's just the wiring for the light as far as I know.

[TrickyDick]

Thanks! I am probably going to need to request help on the arduino forum to get my rig up and running. Waiting on a few bread boarding wires before I can do anything else, and will also need a solution for the heating component and tracking down some halogen bulbs seems best at this point. Before I go posting anything on the arduino forum, was wondering if you had any threads on that site about this project. Thanks.

[Chris Hennes]

Nope, this is the only place I've posted about it.

[TrickyDick]

Yeah, the mess of that Arduino code is my fault: I prefer to work from a command line interface, which the baseline Arduino IDE does not provide. So I used one someone else had rolled together, and it's not actually very good. If I was you I would just pull the source files out of the directory structure I set up and create a new, normal Arduino sketch.

 

I'm not a programmer so most of this is going to be a stretch for me.

 

When you suggest I "pull the source files out of the directory structure", and "setup a new normal sketch", I am not entirely sure what that means.

When I look at the directory structure, I see two folders: lib, and src, plus two files: LICENSE, and README.md.  I'm not sure what kind of files those last two are or what purpose they serve.  When I look into the two folders, under lib, I find another folder DHTlib, which I believe is also included with the Sketches IDE, and includes a few files: dht.ccp, dht.h, readme.txt, and an examples subfolder.  I think I should be able to get this into the sketch with library tools, and be sure I have it "installed".  The other folder SRC has the code file.ino for your sketch.  I assume that you've made no modifications to the DHTlib files.

 

So when I open the *.ino file in sketches, after having installed the DHT lib, and push the verify button, I get the following compile errors:

 

CuringChamberControl.ino:32:1: error: 'dht' does not name a type

CuringChamberControl.ino: In function 'void loop()':

CuringChamberControl.ino:167:32: error: 'DHTLIB_OK' was not declared in this scope

CuringChamberControl.ino: In function 'DH22Reading readDH22()':

CuringChamberControl.ino:268:16: error: expected primary-expression before '.' token

CuringChamberControl.ino:271:25: error: expected primary-expression before '.' token

CuringChamberControl.ino:272:29: error: expected primary-expression before '.' token

Error compiling.

 

edit-(Oh, and it looks like the line numbers listed in this cut-and-paste are +2 from your actual code)

 

I'm not quite sure how to proceed at this point...

 

I'm thinking that the first error means that the dht must be defined as an integer maybe?  not sure.

no clue on the "scope" error

last three errors appear similar and maybe due to a naming convention?

 

Any guidance appreciated!

LIke I said, I'm not a coder/programmer, just a man with a hunger for making some great food!

 

Thanks

 

TD

Edited April 23, 2015 by TrickyDick (log)

[TrickyDick]

Start a new thread. I will answer your questions. 

 

Don't want to hijack this thread.

 

dcarch

Done.  thanks!

 

TD

[TrickyDick]

I had been using my MacBook to fiddle with the Arduino, and oddly it (the IDE) was behaving weird.  It crashed a few times, etc.  I decided to try on a Windows PC and was able to get it to compile properly!!

 

Next steps will be to wire everything up!

 

Couple of questions. 

in wiring the temp/humidity sensor, did you include a 10k resistor connected to 5VDC and pin2 on the sensor as was shown here: https://learn.adafruit.com/dht/connecting-to-a-dhtxx-sensor

is there a way to tune the sensor if the readings are off compared to verified/calibrated measurements?

 

Getting pretty excited about this now!  Would like to ultimately make this do some more things: make programs rather than just operating at static set-points (perhaps with manual triggers to proceed to next step or automated  based on indwelling meat probes possibly); WiFi or ethernet access for remote graphing and saving of logged data, a way to change the setpoints without a re-compile, and an LCD display of current setpoints and actual values for the temp and RH%.  I wish I knew how to program....  I'm not even sure how to use the I2C LCD I bought, and think it'd be easier to just buy a different display without the I2C interface board soldered on.

 

By the way, how did you generate the graph you posted earlier?

 

Thanks again!!!

TD