My Heatermeter 4.0 treated me very well.. but compared to my other PID controller projects (here and here), it lacked one thing I wanted, which was Thermocouple support.
The HM community over at TVWBB is amazing. Bryan and everyone else there (too many to name) are an incredible wealth of knowledge, and the Heatermeter development over the years has been great. With the release of the Heatermeter 4.2.4 (TVWBB Thread, Github), Thermocouple support is now built in. As soon as the components were available, I ordered them up.
If you are going from a HM 4.0 to 4.2.4, there are a bunch of parts you can reuse, like the ATMega, the Raspberry Pi, and the LCD. The rest of the components are pretty cheap so, just order new ones. I ended up getting a new LCD, because, the 10 bucks or so was worth it to me, as I hate desoldering.
I haven’t done surface mount soldering in a very long time.. but, it wasn’t that bad. If my hands were not so shaky, this would look neater. To me, it looks like crap, but it works, so, oh well.
Here are the Thermocouple components soldered on:
Testing per the thermocouple testing procedure.. good to go! (13.8v input)
Bit of soldering later.. all assembled!
Since I reused my Raspberry Pi from my HM 4.0, I just mated up the new HM and it started right up with the old settings. Awesome!
Just waiting on a case and roto-damper now to complete the upgrade project.
While my last PID controller build is extremely versatile and a multi-tasker, the only drawback is that it requires AC power to operate. I recently put together an Ugly Drum Smoker, which unlike my CharGriller, is (somewhat) portable. The need came up for me to build a PID + blower fan rig that could be powered from AC, but also portable power if necessary. Luckily for me, the JLD612 comes in a 12 volt model, and with a background in car electronics, this 12-volt setup was a cake walk. This particular build is not a multi-tasker, just a straight up smoker controller.
While at home, I can power it with a standard 12 volt wall wart power supply, and when on the go, I can use a jump pack, or even a car battery and some alligator clips.
Just like anything I post, this is the way *I* built this unit. Is it the only way to do it? Nope. Is it the absolute best? Probably not. But it works for me, and should give you, the reader, enough information to help you figure out something on your own.
Parts List
Here are the parts I used for my build – many have “See Power Input Notes below” because you can pick and choose whatever type of physical input power connector you wish.. this is just what I ended up with myself. There are infinite choices, many better ones than I have used, you’re free to do what you wish.
Power Input Notes
I chose to use a wall wart for my 12 volt power source (when AC is available), and also put an on/off switch for the whole unit. You don’t need to use either, but you can if you want. I actually bought the wall wart, but, if you go digging in your junk pile at your residence, you will probably find a 12V power supply that works just fine for you from an old phone or router. You may also decide to use this away from any type of power source ever, and just use a 12 Volt battery or jump starting pack (my whole reason for building a 12 volt PID in the first place) – in that case, pick whatever type of physical power input plug works for you. Digikey and Radio Shack have extensive choices, have fun with their catalogs.
Relay Talk
The JLD612 has two different methods of activating the heating device, in our case, a blower fan. It can use the built-in relay J2, or it can use the built in SSR (solid state relay) control. Since I had relays laying around, my build uses the J2 option. If you want to use an SSR, by all means, go right ahead. Sample units are here and here. The advantage of using an SSR is that you could use the built in alarm functions of the JLD612 to activate warning lights (anything, really) on low or high temperature conditions, while using the SSR output for the PID control. In my setup, J2 is tied up with PID control, so only J1 is available for alarm output.
Fan Output – Rectangle in to a round hole?
When I first envisioned this thing, my only real question without having the parts in my hand was if the rectangular output of the fan would mate up to the circular hose barb – more importantly, if I would have to block off the air from the fan exit so that it would only blow out of the hose barb, and not just blow inside the project box. The answer is, no, I did not have to block off any of the fan exit. When I mounted everything, I lined it up as best I could, and plenty of air comes out of the barb without any sort of special ductwork. I am actually impressed at the amount of air that this fan moves.
Component Mounting
I mounted the JLD612 and thermocouple jack first. Make templates with cardboard for the JLD612 and thermocouple panel jack. Transfer these templates to the plastic project box and start cutting. My JLD612 is mounted high on the box as far as I can go, while still being able to attach the wire terminals for pins 6-10 on the JLD612, and leaves enough space for the fan to fit in the box.
Once the JLD612 is in place, I worked on mounting the hose barb, which is the fan output. I first placed the fan in the box and mounted it as high as I could without interfering with the JLD612, but also clearing the plastic ridge inside the box. I then marked its two mounting holes and drilled holes in the plastic box. Using a 2″ M4 machine screw, I secured the screw through the box, with a nut on the inside. I then added 1 nut to each screw, so the fan stood off of the box by about a 1/4″ (eyeballed). Once the fan was mounted, I marked the center location of the fan output, and drilled the hole for the hose barb. Mount the hose barb with the conduit nuts, then adjust the location of the fan so that it is centered in the host barb opening. Once it’s centered, add another nut to each screw to hold the fan securely.
The switch, warning light, and power input jack all mount through drilled holes. The relay inside mounts on one of the fan screw posts with a nut, just so it’s not bouncing around.
Wiring
*Warning light not pictured at the time of writing this
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 as follows on the ‘0089’ set menu:
On the ‘0001’ set menu, I have the following settings, for the high temperature warning light to come on at 230F and go out at 228F:
On the ‘0036’ set menu, I have the following setting due to me using a mechanical relay. For an SSR, leave this alone:
While my CharGriller Smokin’ Pro has done me right over the years, I wanted to build another smoker with more capacity. Originally, I was going to build an offset smoker with a 55 gallon drum. Once I started researching that, I came across plans for an Ugly Drum Smoker, and after a ton of reading, decided to go that route.
My plans were based off all of the reading in the BBQ-Brethern.com thread, as well as the plans from this site. All the credit goes to them.. I didn’t invent anything, I just did a lot of reading and followed recommendations.
Upon setting out, I knew I wanted two things out of this.
For #1, many folks take the lid off of a Weber 22.5″ grill, which fits directly on a 55 gallon drum without any modification. I wasn’t about to drop a bunch of coin just to get a lid, and I don’t need another grill, so I found an alternative. This Uniflame 22.5″ Grill from Walmart has a lid that will fit a 55 gallon drum with a tiny modification – see Thread 1 or Thread 2. Bonus – the grill was on clearance at Walmart, I picked a few of them up for $20 a piece.
The Build
I have friends in the auto industry, and they in turn have access to 55 gallon drums. My cost on the drum was 0, but you can find them in the Philly area quite easily for about $25 if you look on Craigslist.
I also have friends with a Powdercoating business, so I was able to get a quality powdercoating job on the entire outside of the drum done in a nice, bright blue, without breaking the bank. I could have painted the drum like most people, but the powdercoating came out AWESOME and it will last for years to come.
Check out Precision Powdercoating, that’s where I had the drum done. Tell them I sent you!
Anyways ..
First I had the drum completely sandblasted. This is also a requirement before powdercoating, so I probably did not need to get this done twice. In the following pictures, the gray color is the bare metal of the drum after sandblasting.
First step before painting or powdercoating is to make all of the necessary holes and modifications to the drum.
Once all of the holes were done, I disassembled everything and sent the drum out for powdercoat (outside of the drum only!). Once it came back, I mounted all of the hardware up, using stainless hardware. To seal the drum well, you should use high temp RTV around each and every fastener from the inside of the drum (yes, it is food safe). I didn’t do this step, and I had a ton of oil leak out of each and every fastener hole, staining my fresh powdercoat job 🙁 Seal the aluminum lip for the lid, from the bottom of the lip inside the drum, to keep air from leaking out. I used a flashlight place inside the drum, facing up at my face, to see the air gaps and make sure I sealed it properly.
For the charcoal basket, I used the charcoal grate from the Uniflame grill, and expanded steel. I bent the expanded steel around a propane tank to get the basic shape, then welded it to the grate and itself, forming a cylinder. I then took a cheap $5 aluminum pizza pan from Walmart to use as an ash pan, using stainless 3″ bolts to offset it from the rest of the basket.
That’s about it! Along with my 12v PID controller, the UDS has proven to be quite awesome!
More pics:
(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.
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
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:
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:
Some more pictures of the box: