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My homemade digital temperature controller!

I got my large BGE in 2010, and have loved it and used it extensively.  I wanted a temperature controller so I could do other things (such as sleep) while smoking or drying things.

I've chipped away at a few iterations of one over the last couple of years, and am now completely finished.

Check out this video of it in use:

https://vimeo.com/90480641

Please let me know what you guys think!

thanks,
Eric
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Comments

  • GATABITESGATABITES Posts: 1,257
    Thats a nice contraption. With the engineering involeved, it needs a better name than "contraption."

    What is your background in? Pretty cool man. 
    XL BGE 
    Joe JR 
    Baltimore, MD
  • CanuggheadCanugghead Posts: 6,155
    Very cool man. What was the lower vent opening for each target temp, perhaps 1/2", 1" and 1.5" respectively?  Any plan to incorporate a fan?
    canuckland
  • NPHuskerFLNPHuskerFL Posts: 16,836
    edited March 2014
    Very innovative! What are you setting the bottom draft at as I don't see any sort of blower? How hard would it be to add a 3rd Ktype thermocouple plug in. Ie one for grid and other two for multiple cooks? I like it! "Shark Tank" here you go. ? ;)
    LBGE 2013 & MM 2014
    Die Hard HUSKER & BRONCO FAN
    Flying Low & Slow in "Da Burg" FL
  • reinhart36reinhart36 Posts: 178
    Hi guys,

    Thanks for the comments and questions.  It's exciting to finally get to share my project.

    The bottom draft is just opened all the way for all operating temperatures.  The top damper has full command over such a broad range of airflow rates that the setting of the lower damper doesn't matter (as long as its open).

    No plan for a fan at present, thought it's an interesting idea.  It lights up pretty fast, and I like that it doesn't really need much electricity to operate.

    Adding another TC channel would be easy enough.  There's some more real estate on the PCB for an additional amplifier, and the PIC18 controller has more available pins for listening to it.

    Thanks again for the feedback!
    Eric
  • SoCalTimSoCalTim Posts: 2,151
    Impressive.
    I've slow smoked and eaten so much pork, I'm legally recognized as being part swine - Chatsworth Ca.
  • reinhart36reinhart36 Posts: 178
    Hi Gatabites,

    Thanks for the interest and feedback.  I agree - a name would be cool..  I'll have to ponder that a bit!

    I'm an aero engineer by trade, but I took up digital controls as a hobby because I liked my grill so much!

    take care,
    Eric
  • Cookbook_ChipCookbook_Chip Posts: 1,217
    It was very entertaining to watch it work! Question- where are you with birds chirping all happy at 10F?
    Lovin' my Large Egg since May 2012 (Richmond, VA) ... and makin' cookbooks at http://familycookbookproject.com
    Stoker II wifi, Thermapen, and a Fork for plating photo purposes
  • NPHuskerFLNPHuskerFL Posts: 16,836
    edited March 2014
    Quite remarkable! With bottom draft open (assuming it's fully open with screen) you were able to maintain at 180F, 250F & 350F using the simple servo (somewhat like a an A/C duct damper servo). Was it able to maintain for low and slow 12-20+ hrs assuming there is enough lump? Is this AC or DC powered (convertor or step down transformer)? Also does the creosote buildup adversely affect the operation (hard to clean?). I would think this is a marketable device. Very Nicely done =D>
    LBGE 2013 & MM 2014
    Die Hard HUSKER & BRONCO FAN
    Flying Low & Slow in "Da Burg" FL
  • reinhart36reinhart36 Posts: 178
    Haha - thanks!

    Yes, I purchased the birds chirping, I'm afraid.  I wish it sounded like that in my back yard in january.

    take care,
    Eric
  • BYS1981BYS1981 Posts: 2,521
    NERD!


    Lol cool. Is it operating off batteries? That would be cool.
  • reinhart36reinhart36 Posts: 178
    Yes - huge nerd, I'm afraid. :)

     It can operate from batteries, though I wasn't using them in the video.  I wanted a backlight on the LCD the whole time, which would use up batteries a bit quickly.

    Without the display backlight on though, it's perfect for battery operation since it doesn't really need much electricity.

    When the grill is at the right temperature, the controller simply doesn't do anything.

    Thanks again for the question, and for taking time to watch my video.

    Eric
  • reinhart36reinhart36 Posts: 178
    Quite remarkable! With bottom draft open (assuming it's fully open with screen) you were able to maintain at 180F, 250F & 350F using the simple servo (somewhat like a an A/C duct damper servo). Was it able to maintain for low and slow 12-20+ hrs assuming there is enough lump? Is this AC or DC powered (convertor or step down transformer)? Also does the creosote buildup adversely affect the operation (hard to clean?). I would think this is a marketable device. Very Nicely done =D>

    Hello,

    Your complements are appreciated, and your questions astute.  Yes, low and slow is great until the fuel runs out.  I should get a larger memory card for my camera to demonstrate.

    The controller is powered with a common 6V DC "wall wart," in the video.  Any DC power source >= 6V would suffice.  The controller has a 5V voltage regulator on the PCB.  That supplies power to everything.  I think the regulator is 750ma or so.  I tried a smaller one early on, and the LCD would dim a little when the servo moved.  Now it's good to go.

    The creosote/crud was something I was worried about from the beginning.  Thankfully, I lucked out and it isn't a factor.  I cleaned the damper for my demo, so it's look pretty though.

    Thanks again for your interest - I'm having a blast sharing this.

    Eric
  • bo_mullbo_mull Posts: 360
    I like it, Wish I had the smarts to do something like that.

    Cleveland, TN.

    LG BGE, PSWOO2, Stoker WIFI.

  • johnkitchensjohnkitchens Posts: 5,056
    That is a great setup. Very impressive!

    Louisville, GA - 2 Large BGE's
  • CanuggheadCanugghead Posts: 6,155
    just watched the video again, 
    1) you should get it copyrighted
    2) did I see you handle the platesetter with one hand? you must be strong and brave!
    canuckland
  • calikingcaliking Posts: 10,718
    This looks like an 8 th grade shop project.





    Kidding! :) very very cool, dude! I've wanted to build a temp controller for a long time but know how to plug in a soldering iron, and that's it. Your controller seems to be really functional. Thanks for sharing the video.

    #1 LBGE December 2012 • #2 SBGE February  2013 • #3 Mini May 2013
    A happy BGE family in Houston, TX.
  • BYS1981BYS1981 Posts: 2,521
    I'd take the video down and file a copyright.
  • BustersdadBustersdad Posts: 309
    That is very cool...
  • That is cool...it changes the way I think about the bge...I've always made few changes at the damper and adjusted the door...interesting.
    Making the neighbors jealous in Pleasant Hill, Ia one cook at a time...
  • nolaeggheadnolaegghead Posts: 26,331
    That's the most brilliant thing I've seen on this forum in a long time!

    Someone else had one where the controller was a bi-metallic coil, and the pre-tension controlled the setpoint.  Did the same thing, control the top damper, but it was purely mechanical so no logging or cool displays.
    ______________________________________________
    This is my signature line just so you're not confused.  Love me or hate me, I am forum Marmite.
    Large and Medium BGE, Kamado Joe Jr, Akorn Jr, smoker with a 5k btu AC, gas grill, fire pit, pack of angry cats, two turntables and a microphone, my friend.  Registered republican.
    New Orleans, LA - we know how to eat 

  • cazzycazzy Posts: 9,058

    That's the most brilliant thing I've seen on this forum in a long time!

    Someone else had one where the controller was a bi-metallic coil, and the pre-tension controlled the setpoint.  Did the same thing, control the top damper, but it was purely mechanical so no logging or cool displays.

    If you have Nola's seal of approval, then you've done well my friend!!

    You have the perfect mono tone voice for product demos. My guess is that this isn't your first rodeo.
    Just a hack that makes some $hitty BBQ....
  • Very nice!  Agree with others on copyright and marketability.  Did you build the mini computer from scratch or did you start with some other baseline such as raspberry pi?
    Michael 

    Winston Salem, NC


  • yzziyzzi Posts: 1,793
    edited March 2014
    That's a really nice controller. I like that it doesn't use a blower. Now the question is are these plans open source or proprietary?
    Dunedin, FL
  • reinhart36reinhart36 Posts: 178
    That's the most brilliant thing I've seen on this forum in a long time!

    Someone else had one where the controller was a bi-metallic coil, and the pre-tension controlled the setpoint.  Did the same thing, control the top damper, but it was purely mechanical so no logging or cool displays.
    Thank you very much!

    I contemplated going the bimetallic route, but it could only be "calibrated" to be accurate for one environment.  For example, if the humidity of charcoal type changed and a different relationship was needed between airflow rate and temperature, you'd be out of luck.  That being said, a simpler bimetallic element type of control is still very cool.

    I appreciate the feedback, and you taking the time to watch my video!

    Eric
  • reinhart36reinhart36 Posts: 178
    Very nice!  Agree with others on copyright and marketability.  Did you build the mini computer from scratch or did you start with some other baseline such as raspberry pi?
    Your feedback is appreciated!

    The controller is a Microchip PIC18F series general purpose controller.  I think they go for about $2, but you have to build it into a board yourself "from scratch."  A person could go a lot of ways, such as using something like a Rasberry Pi, or a Basic Stamp or similar.

    Several thousand lines of code needed to be written for this approach, but it was interesting.

    Thanks again!
    Eric
  • JethroVAJethroVA Posts: 967
    Dude, seriously, file for patent right away. And as others said, take the video down. Or sell the rights to me!
    Richmond, VA. Large BGE, Weber gas, little Weber charcoal. Vintage ManGrates. No FireWires Yet. Hoping to win some soon.
  • reinhart36reinhart36 Posts: 178
    JethroVA said:
    Dude, seriously, file for patent right away. And as others said, take the video down. Or sell the rights to me!
    :) 
  • cazzycazzy Posts: 9,058
    That's the nature of a geek...sometimes things are not financially motivated. Sometimes it's just for the sake of tinkering just to see if it can be done.
    Just a hack that makes some $hitty BBQ....
  • pineypiney Posts: 1,286
    reinhart, just as suggested file for patent, copyright or whatever now! You are too damn smart!! I love it.
    Lenoir, N.C.
  • Very impressive.  Sounds like you put a lot of effort into your model.  Is it fuzzy?
    Simi Valley, California
    LBGE, PBC, Annova, SMOBot
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