Jan 24 2012

DIY PID Control for BBQ, Sous Vide, Mash Tun, whatever….

Posted by Seth in BBQ, Food, Homebrew
My DIY PID Controller for BBQ, Sous Vide, Home Brew

My DIY PID Controller for BBQ, Sous Vide, Home Brew

 (update: go HERE for a 12 volt BBQ controller!)

 

I’ve been slacking on the blog, I know, been busy!

Here’s a project that’s been in the works for a while, and I wanted to test it out to make sure it works well before sharing with everyone.. well, here it is! A DIY PID controller for a smoker, sous vide cooking, mash tun, whatever you can think of, that doesn’t break the bank. After a few runs in the smoker and sous vide (a la crockpot), I can say, it’s awesome !!!!

What is PID? Basically you tell it what temperature you want something, and it figures out how to hold that temperature. It’s nerdy and involves lots of math.  I can’t explain it too well, so go and read about it here.

PID Controller, Sous Vide style, powering a crockpot

When I set out to build this, I wanted to keep costs down (obviously), but I wanted it to be versatile, so I decided to build everything with modular plugs, so that thermocouples and outputs could be swapped in a matter of seconds.  Everything fits into a project box, and all you do is plug in power (input), a thermocouple (thermometer for you noobs), and then plug in an output device, whether it is a blower fan, a crock pot, a heating element, whatever. All of the components in my design are good for 15 amps, so a ~1500 watt heating element should be no issue. Wiring is simple and contained completely within the project box. I chose to do a simple design for the first incarnation of this device, but I have some ideas for another one. The PID controller has alarm outputs (such as over/under temperature) that could potentially control other items, such as a damper to release extra heat in the smoker, outputs to my X10 devices to page me, etc… the possibilities are endless.

Parts List

  • 1x JLD612 PID Controller – $33.50 US
  • 1x Submersible thermocouple – $19.50 US – this is for Sous Vide only
  • 1x PT100 thermocouple – $16.50 US – this is mounted in my smoker
  • 1x ESSR-25DAC 25amp DC in / AC Out Solid State Relay (SSR)- $8.95 US
  • 1x EHS-SSR25A  heat sink for the SSR – $4.25 US
  • 1x TPJ-U-F thermocouple panel jack – $4.50 US
  • 2x OTP-U-M thermocouple male plug – $3.50 US each (only need one per thermocouple
  • 1x 486-1083-ND – female NEMA-15 outlet (output outlet) – $1.42 US
  • 1x CCM1909-ND – power entry module w/ switch (input) – $7.66 US (you can go with a more simple input plug without a switch, but I wanted a switch on mine, and these fit your standard computer power wires)
  • 1x HM928-ND project box – $17.82 US – Digikey’s site is very easy to search, if you need a bigger box, then look around – just make sure the dimensions are deep enough for all of your components.
  • 1x 1053-1118-ND 14CFM blower fan – you can go bigger or smaller, this one seems to work great on my Chargriller
  • 2x Barrier strips, at least 3 positions – like these – don’t forget the jumpers
  • 1x stainless steel pet water bowl, to mount the fan to the BBQ – see picture.  Found it at Walmart for a few bucks
  • Various M4 screws, to mount SSR heatsink to the SSR. Take them both with you to Lowe’s/Home Depot and figure it out
  • Heat sink paste for the SSR
  • Various quick disconnect crimp connectors.  If you have a well stocked electrical connector box for automotive stuff, that will get you through it
  • Hot glue gun to mount components like the barrier strips
  • Dremel tool / drill, to mount everything in the box

Wiring

Wiring is pretty easy – you can see most of it in the picture.  Use at least 14ga on the 120volt stuff.  The DC is low current, but I still used 16gauge because that’s what I had around.  Thermocouple wiring comes with the thermocouples, I just changed the connectors.  Specific wiring info:

  • For 120v – the hot side of the input module goes through the switch and feeds a barrier strip.  One barrier strip output goes to the output side of the SSR, the other output goes to the PID controller on pin #1. SSR Output goes to the output module hot.
  • The neutral side of the input module feeds a barrier strip.  One barrier strip output goes to the neutral of the output module, the other goes to the PID controller on pin #2.
  • The ground wire goes directly from the input module ground, to the output module ground.
  • The thermocouple panel has one plug that is larger – I used that for the red. Connect that to pin #8 on the PID. Connect the two blues to pins #9 and #10
  • Connect Pin #6 of the PID to the + Input of the SSR
  • Connect Pin #7 of the PID to the – Input of the SSR

PID Controller, wired up in the project box

Component Mounting

Mounting components was simple.  The input module, output module, PID controller, and thermocouple plug all require some dremel work to make mounting holes, then they snap into place. I used some hot glue for added security. My input is on the right in the picture above, the output and thermocouple  is on the left.

The heatsink mounts to the project box with screws, those are the 2 screws that you see on the first picture of this post that show through the front.  I did not want to use glue for this part, as this part gets hot, I don’t need it coming loose inside.

When mounting the Thermocouple in your smoker, you want it as close to the cooking surface as possible, and also nearest to any potential hotspot.  Remember, with smoking, high temperature is bad and will ruin food, low temperature only extends cooking times. On my Chargriller Smokin’ Pro, this meant the thermocouple was mounted about an inch off of the cooking surface, on the right side of the cooking area, nearest to the side fire box.  My smoker can vary temperatures up to 15 degrees from side to side.

That’s about it as far as construction goes!  You will want to familiarize yourself with the PID controller manual  and set all of the configuration parameters properly on the first use.  My settings are:

  • IntY =  PT 10 0   (Pt100 thermocouple, this setting will show temp in .1 increments)
  • OutY = 2 (PID controls SSR )
  • rd = 0 (heating control)
  • CorF = 1 (Fahrenheit)
The  PID settings are set through the AutoLearn function of the JLD612.

Blower fan, mounted on the side firebox of a Chargriller Smokin’ Pro

As for usage of the device, it’s too easy.  For me, every time I fire up the BBQ or Sous Vide, I put in my set temperature, and kick off the autolearn function of the JLD612, and walk away.  It will figure out how to control the temperature on its own. Four Sous Vide and any type of electric heating element, the accuracy is surprising – it will hold temperature to within .1 degree F with no trouble at all.  For something like a smoker that has varying amounts of fuel, it does a great job from temperatures becoming too cold when you are low on fuel, but be very careful about adding too much wood or charcoal.  I am very familiar with my smoker and know how much it needs, but you can easily overdo it and have a fire much hotter than you desire.  Remember, this device (as-is built in this post) can only add heat, it cannot remove it.  If you want to get fancy with alarm outputs, you could definitely use this controller to trigger some sort of contraption to clear heat out of a smoker if need be.
The results.. see for yourself!!

Here’s a brisket that was done using this controller

 

Teriyaki Chicken Breast, Sous vide

 

Some more pictures of the box:

Another wiring view

 

Thermocouple port and output port

 

Input module, accepts standard computer power supply plug

 

Thermocouple mounted on the smoker (since moved to the other side)

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41 Responses to “DIY PID Control for BBQ, Sous Vide, Mash Tun, whatever….”

  1. jimmy Says:

    Great build! I am about to build out your temp controller and was wondering if i could replace your outlet plug with a gfci? do you think it will fit the project box that you used, or should i go with a larger size? thanks!

  2. Tullyamo Says:

    I have had this same PID for over a year now and I guess I must have set mine up completely different. I’ve made it too complex for anyone else to use it. The auto tune feature in the manual is vague on how it operates, so I am going to ask you the few questions that I can think of.

    1. If I set my temp at 220f and hit auto tune, how long do I need to wait for it to gather the settings?

    2. If it has auto tuned is the purpose to keep it right at the set temp I have entered?

    3. On your smoker, you say you’ve set the thermocoupler 1 inch above the grill surface and on the right side of the smoker. How from from the end of the smoker did you set it? That side of the box gets extremely hot.

    4. Have you done any modifications to the smoker itself such as a thermo shield or moving the chimney?

    5. when you smoke are you raising the charcoal bed up and using a water bath below the grill surface?

    6. How is the fan connected to your pid box?

    7. Lastly, are you keeping the damper at the top all the way open or do you close it a little?

    Thankyou for any information you can give me on this. Your design is way more simple than what I have done and I wish to set mine up very closely to yours. The PID is an awesome feature though to have. I have smoked upwards of 50 loads through my USD and 100 through the Grillin Pro. Each time, perfection has been reached.

  3. Tom Price Says:

    Very neat looking build. I did something similar, but mounted the heatsink outside the box. I was worried it would get hot. It probably only has to dissipate 15 W full blast so maybe that wasn’t necessary. Does your controller get hot?

  4. iceman Says:

    Nope, never seems to get hot that I can notice.

  5. iceman Says:

    Sorry for the super late reply on the first post! Here are my answers in line.

    1. If I set my temp at 220f and hit auto tune, how long do I need to wait for it to gather the settings?

    —–> I haven’t sat around and watched, honestly, but the light is usually gone by the first addition of more wood.

    2. If it has auto tuned is the purpose to keep it right at the set temp I have entered?

    —–> Exactly!

    3. On your smoker, you say you’ve set the thermocoupler 1 inch above the grill surface and on the right side of the smoker. How from from the end of the smoker did you set it? That side of the box gets extremely hot.

    —–> I’d say 4-5 inches. That side of the box is hot, which is exactly why I put it there. I want the hottest part to be at my set temperature to avoid over-cooking.

    4. Have you done any modifications to the smoker itself such as a thermo shield or moving the chimney?

    ——> I’ve extended the chimney down to cooking level with a ducting piece from home depot. When I smoke, I flip the charcoal grate upside down inside the smoker, and have it as low as it can go so I can squeeze drip pans between it an the grates. On the right side where the entrance from the firebox is, I make a wall with tin foil so the smoke comes out a little ways in, and doesn’t exit straight up (with all the heat, too). Other modifications are inside the firebox. You can see some here -> http://www.ice8420.com/thumbnails.php?album=98

    5. when you smoke are you raising the charcoal bed up and using a water bath below the grill surface?

    —–> Correct, water bath/drip pan between grill surface and upside-down charcoal bed.

    6. How is the fan connected to your pid box?

    —–> I put a standard 2 prong 110v plug on it, it connects directly to the output of the PID.

    7. Lastly, are you keeping the damper at the top all the way open or do you close it a little?

    —–> It’s about 40% open

    Thankyou for any information you can give me on this. Your design is way more simple than what I have done and I wish to set mine up very closely to yours. The PID is an awesome feature though to have. I have smoked upwards of 50 loads through my USD and 100 through the Grillin Pro. Each time, perfection has been reached.

    —> You’re welcome!

  6. iceman Says:

    A GFCI would need a wider and deeper box, this one is tight! But yes, no reason why you couldn’t place one in here. Alternatively, plug into an outlet that is GFCI protected like I do.

  7. Rich Says:

    Hey great idea. I am an avid home brewer and working hard at perfecting my Q. I like everything you have but would like to add a switch so I could “manually overide” the device on the output side. Say run the pump for cleaning or transfer or run the smoker fan at initial lighting the lump. I realize I could just raise the temp setting on the PID but would rather have a switch. Something like off/auto/manual on. Anyway you could tell me how to wire that into the mix? I am just a tad electricaly challenged. Thanks!

  8. iceman Says:

    Hi Rich,

    Two ways of doing that .. first would be to have a SPDT (single pull, double throw) switch. One of the inputs to this switch would be 120volt AC hot, the other input would be from the SSR output. The output of the SPDT switch would be to the output outlet. That would let you bypass the operation of the SSR and directly energize the output outlet – just make sure your switch is rated for that type of amperage. Example switch.

    Second way would also be a SPDT switch to energize the SSR that is already installed, which is the way I would go to avoid having another high current switch. Unfortunately, to energize the relay, you need DC voltage to do it.. which is not available in this project, it’s only provided by the PID controller itself.

  9. Rich Says:

    Thanks for the quick reply. I am somewhat electricaly challenged, but a quick learner 😉 As long as my project box is large enough would it be possible to take a wall charger of some sort and put it inside the box (hot glue maybe). Next power the standard “wall prongs” with wires from the load and neutral barrier strips. Finally take the DC power supply’s out to switch the SSR bypassing the PID? The way I read that SSR it can take in 3-32VDC so would any small wall charger in that range work? Thanks much! I owe you some home brew and pulled pork.

  10. iceman Says:

    Hi Rich,
    I did read that the SSR can take 3-32vDC as well. You could certainly try a wall wart.. but even easier, you could probably find an AC DC converter on digikey that would do the trick and is much smaller.

  11. doug h Says:

    i purchased a ta4 pid controller. I am having trouble setting the parameters. Any suggestions would be appreciated.

  12. iceman Says:

    Does it have an auto tuning function? I would start there. I’m not familiar with a TA4.

  13. doug h Says:

    yes it does. The problem is it asks for p-value and s-value, etc. made in china with someone who is chinese and learned english as second language to write the instructions. Clear as mud.

  14. Ian Says:

    Hello.

    I was wondering … Is it possible to change out the fan blower for a hot plate without changing anything? I am building an electric smoker but I will be using a 220 v heat element . What do you think. This is a great build by the way.

    Thank you.

  15. iceman Says:

    Hi Ian,
    The build I did is 110V only. It looks like the JLD612 will accept 85-265V as power, and the relay will also control 24-380V, so no reason why you could not do a 220 build the same way, just change the physical plugs to what you need.

  16. Doug Says:

    How long should the autotuning run? Had mine going for about an hour. It was still going ?

  17. wilks Says:

    Help Please!!!! I’ve assembled this, same componenets, but the temperature is correct when i switch the unit on, however, when the water heats up, the temperature readout starts reducing… at boiling point the temperature reads -28DegC. (negative 28deg).
    Even on Autotune, the PID keeps that number, and the water continues to boil for 15-20mins, until i disable and switch the unit off. My current settings are:
    Inty- E / Outy-2 (using SSR) / ATDU – 10 / PSB – 0/ RD – 0/ ConF-0 / P – 0.2 / I – 2000/ D- 0
    Any ideas??
    Thanks and have a happy new Year!

  18. iceman Says:

    Hi Wilks,
    Off the top of my head, I think I remember reading in the PID manual that the temperature would go down if you had the leads reversed on the thermocouple. Check your connections from the thermocouple to pins 8-10 on the JLD612.

    I should have asked a few posters ago, but how did everyone come across this page, a google search?

  19. iceman Says:

    I haven’t watched it in a while, but my auto tuning did run a couple hours on the smoker. It’s much faster when doing sous vide.

  20. Tommy Says:

    To answer your question, I found this via Google.

    I’m in the process of ordering everything you have listed here and I have a question. Is there any way to see what parameters the unit uses after running an auto tune? I know the unit saves the parameters, but would it let you see them so you can write them down? Ideally, I’d like to be able to use pre-set parameters to cut down on auto tune time for BBQ.

    Great resource. Looking forward to sharing my results when I am finished.

    -T

  21. iceman Says:

    Hi Tommy,
    I will have to power it up and look, I’m not sure.

    I actually just started another unit today, a little different, though.. I built one that is 12volt powered with a 12V JLD612, with a blower fan and PID controller all in the same box – self contained unit. I built an ugly drum smoker recently, while I could have just made a blower fan to use for that grill, I wanted something 12V powered as I will not always be near electricity with this smoker.

    Thanks for reading! Let me know how you make out.

  22. Bob k Says:

    I am new to all this an have no electrical experience. How did u wire the FUSED INLET WITH SWITCH, SNAP IN PANEL MOUNt. What went where? Step by step for each connection on the snap in panel mount would help me a lot. Thanks

  23. Bob k Says:

    Not sure how to connect the back of the FUSED INLET WITH SWITCH, SNAP IN PANEL MOUNT( fuse/ switch/ pos/neg/ground)

  24. iceman Says:

    Hi Bob,

    See the first bit in the wiring section. The input module has 5 prongs – 3 are the 3 plugs that come in from a power wire, the other two are for the built in switch. The 120V hot (black) connects from its prong, to one of the switch prongs. The other switch prong gets connected to the 120V hot barrier strip. The neutral prong feeds the neutral barrier strip. The ground goes directly from input module to output module. Hope that helps.

  25. Bob k Says:

    Thanks
    I might have figured it out w/ an ohm meter. My inlet has seven prong. I’m not sure if we have the same inlet. I tried to post a pic, but did not work. Any suggestions?

    Thanks for your help

  26. iceman Says:

    Post a link to it if you can from where you purchased it?

  27. Bob k Says:

    http://www.amazon.com/gp/product/B00511QVVK/ref=oh_details_o04_s00_i02

  28. Tommy Says:

    Just finished building mine tonight. Super pumped to try it out.

    I had the same plug that Bob purchased, so if he needs any advice as to how to wire it up, please let me know!

    Thanks for making this resource available to all of us!

  29. iceman Says:

    Awesome, Tommy.
    Looking at Bob’s plug, just looks like a SPDT.

  30. Tommy Says:

    It’s a DPST. If you go with a switch that has a built in light, then you have to run both the neutral and live wire through the switch. That way, when you throw the switch, it passes both lines through the switch AND closes the circuit for the light.

    With three plugs coming in from the power cord receptacle (hot, neutral, ground), two plugs for one side of the switch, and two plugs for the other, you end up with 7 plugs. If he looks closely though, the input plugs from the receptacle are labeled W, L, and E. Took me some time to understand.

    Thanks again for this resource!

  31. iceman Says:

    Ugh, DPST I meant. Need to stop reading late at night. Thanks !!

  32. Rich Says:

    Sorry to bother you again. Please see my post back in October. Trying to set up a box for my March pump for brewing and got the SSR you show along with DC power supply. Trying to add a switch that will function as On/Off/Auto where On=Manually on all the time and auto is controlled by the PID temp. I made a .jpg with all my actual parts. Any chance you could/would right click it and save it and draw some black/white/green/red wires on it to help me out? Gretly appreciated! picure is here http://mantistech.com/beer/WireMe.jpg I think you get my email from the post. If not write back and I post if for you. Thanks a ton.

  33. Tom Says:

    Could you maybe hand draw your wire connections? Particularly from the the barrier strips with the jumpers included since its hard to see most of the wiring. Im a visual person (sorry), the pictures a little confusing since I cant see everything.

  34. Anyone dual-purposing a PID for RIMS and a BBQ blower fan? - Home Brew Forums Says:

    […] bad! I just found this, right after I posted my thread. http://www.ice8420.com/blog/2012/01/diy-pid-control-for-bbq-sous-vide-mash-tun-whatever/ Looks like it should work. I'm just wondering if there's something different about the output. My […]

  35. Ivan Says:

    Hey iceman, just want to say thanks for the write up and all the work you put into this. As i was setting out for this adventure there are so many options out there and the one that i liked most was the digiq but the cost is just way way to high for me to make it a reasonable purchase especially if i am not competing. Then I ran into your idea and thought it was fantastic. One thing I was curious about could there be an additional thermocouple for meats? Or is that just in a whole other league of DIY’s? I only ask because there is this ramp down feature that the Digiq has and it was very interesting but if you can set parameters to adjust to the temp of the meat that would be awesome. And one last thing does this produce an alarm sound when temps have fallen? Thanks again and i probably will be making my purchases pretty soon.

  36. Seth Says:

    Hey there,
    First of all, thanks for reading, and especially posting. Much appreciated.

    Unfortunately with this PID, there’s only one temperature input. If you wanted something for meat, you’d have to have a separate device.. which is what I do (bunch of cheapie remote thermometers at the moment).

    You can use the alarm outputs to turn on lights, sound beepers, whatever you want – endless possibilities in that department.

    My next project is putting together a heatermeter – I have all the parts, just have to solder them up. Fan control + meat temp + all kinds of awesomeness

  37. Ivan Says:

    Hey Seth,

    Not a problem, hmmmmm i like that next project you are putting together!!!

    I did the math on your parts it came out to be 117 for everything not including shipping which isnt to bad, looking at the shematics of things I should be able to put it together haha. Ill just get a wireless Mavrick, heard those are pretty cool and work awesome. So this has the capability notify if and when I need fuel or temp drop?

    Thanks again
    Ivan

  38. Seth Says:

    Hey Ivan,

    I wouldn’t call it an advanced”notify capability” so much.. but you do have the ability to set temperature alarms, and it will turn on/off relays depending on those alarms. You could, in theory, have it set off a buzzer, or light up a light, at whatever temperature you want. It only has 2 alarms, though. Something like a Heatermeter is a bit more advanced as there is a computer behind the scenes. Hope that helps.

  39. frank l jones Says:

    how to make this work? I want to build a controller
    such as this only I want to use it with a diy vacuum pot its made of stainless steel so what to do to get the temps of 115f? would the sensor sit between the bottom of pot basically between bottom of pot and hot plate?
    hope to hear your thoughts
    frank

  40. Adam Says:

    Hi! Currently following this guide and am super excited about this device. I am having a little trouble with the output module. None of my crimp terminals seem to fit in the female terminals for the output. What size/shape connect did you use?

  41. Seth Says:

    Hi Adam,
    There are all different types of male fork connectors. The regular ones you may find at a local may be too wide. You can either bend them slightly if you don’t feel like buying a whole load with some pliers.. or.. get the ones made for it. I don’t remember the size off of my head, but if you google ‘male fork crimp terminals’ you’ll find a site like this, that has the specs.
    http://www.elecdirect.com/catalog/crimp-wire-terminals/spades-forks

    I have a big pile of crimp connectors so I have all different sizes that fit in there.

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