They say "low & slow is the way to go".
I had built a simple Smoker controller in a previous instructable. For V2 it's time to go big.
I had posted a Wifi Meat Thermometer here before. I figured why not combine that with the smoker controller.
I got this car diagnostic meter at a swapmeet and decided to make it into a new Monster Smoker Controller.
Step 1: Gut It!
My favorite part of most projects is taking it apart. I save any scraps that wont be reused this time.
Who knows what they may get used for later.
i use these little divided drawer organizers to keeps the screws separate.
Also helps to have a cookie sheet on you table to work on top of. It catches the screws that fall.
I actually use an old cargo tray from a car.
Step 2: The Meters
I bought this cool software from Tonne Software that lets you make Meter Faces. They have a free version that only does one scale.
One of the meters had a few stress cracks in the case but they both worked great. A little cement melted those cracks shut.
After you design your meters just paint the old faces or flip them over so you have a blank slate.
I use 3M Sprayment but any contact cement should work. Just be sure your face plate is clean....
Step 3: Power Relay
My smoker draws 12 Amps so I went for some large parts here. I used a 240V 45Amp solid state relay mounted to the bottom of the case. I ground a section on the aluminum case flat and used some heatsink grease for good measure.
I used a simplex AC outlet and a recessed plug with some 12Ga wire leads.
The hole saw I use is a little large for the outlet so I 3D printed a ring to take up the extra space...
Step 4: Connectors and Switches
At first I thought I would put the connectors on the front but then I realized I had some nice round switches that would fit there. I drilled a few extra holes and put switches from one side to the other.
A Unitbit makes short work of this but does drift a bit if you're not careful.
For the thermocouple I used some binding posts and for the meat probes I use these locking connectors.
I found a new slide switch to fit the existing hole in the front panel. I cut LCD slots that covered up hte remaining holes. I 3D printed some nice bezels for these.
I only added one pilot light but its an RGB led..
Step 5: Assembling It
Everything went together pretty easily. I used the same code as in the previous instructables. (see links in intro). I just added a pwn output to drive the meters. i scaled them so 97% pwm pins the needle to the end. I like to know when things go wrong....
Only difference is I didn't use a Linkit. I opted for a another atmega 328. Now I will probably go back and add the wifi. It really was nice to have. Or maybe I'll start on V3...