[Jason] learned a lot by successfully automating this meat smoker. This is just the first step in [Jason’s] smoker project. He decided to begin by hacking a cheaper charcoal-fed unit first, before setting his sights on building his own automatic pellet-fed smoker. With a charcoal smoker it’s all about managing the airflow to that hot bed of coals.
[Jason] started by making sure the bottom was sealed off from stray airflow, then he cut a hole into the charcoal pan and attached a length of steel pipe. The opposite end of the pipe has a fan. Inside the pipe there is a baffle separating the fan from the charcoal pan. The servo motor shown here controls that valve.
The pipe is how air is introduced into the smoker, with the fan and valve to control the flow rate. The more air, the higher the temperature. The hunk of pipe was left uncut and works fine but is much longer than needed; [Jason says] the pipe is perfectly cool to the touch only a foot and a half away from the smoker.
With the actuators in place he needed a feedback loop. A thermocouple installed into the lid of the smoker is monitored by an Arduino running a PID control loop. This predicts the temperature change and adjusts the baffle and fan to avoid overshooting the target temp. The last piece of hardware is a temperature probe inside the meat itself. With the regulation of the smoker’s temperature taken care of and the meat’s internal temperature being monitored, the learning (and cooking) process is well underway.
There are many, many smoker automation projects out there. Some smokers are home-made electric ones using flower pots, and some focus more on modifying off the shelf units. In a way, every PID controlled smoker is the same, yet they end up with different problems to solve during their creation. There is no better way to learn PID than putting it into practice, and this way to you get a tasty treat for your efforts.
Here’s a round-up of three different Fubarino Contest entries; a video of each is available after the break.
On the upper left are the beginnings of a network node monitoring system developed by [Stephane]. When the network checks the weather, it may determine that it’s far too harsh outside and time to go in to see what’s new on Hackaday. There’s only sparse information available on the hardware. Each node uses an ATtiny84 and an RFM12B—different sensors connected to each are used to build up the network’s data collection capabilities.
In the lower left is [Brett’s] Bluetooth door lock controller. The Arduino, a cheap Bluetooth module, and a relay board make up the base station which will eventually connect to an electronic lock. [Brett] uses a smart phone to punch in the access code, and entering “1337” four times in a row unlocks the Easter egg, displaying our URL on the character LCD. Here’s the code repository for his project.
[Matt] wanted to have more control over his meat smoker so he built this advanced PID smoker controller. It uses the solid state relay seen in the bottom-right of this image to switch the smoker’s heating element. But all of the other goodies that are included add several features not usually found in these builds.
This is a replacement for the commercial PID unit he used on the original build. That monitored the temperature in the smoker, using predictive algorithms to maintain just the right heat level. But this time around [Matt] is looking for extra feedback with a second sensor to monitor meat temperature. Using an Arduino with an SD shield he is able to data log the smoking sessions, and his custom code allows him to specify temperature profiles for resting the meat after it has hit the target temperature. It kind of reminds us of a reflow oven controller… but for food.
Bringing that smoky goodness to your cooking is neither hard, nor is it expensive. [Alton Brown], who we consider to be the MacGyver of cooking, always seems to be able to build cooking contraptions from common items. The smoker he built from a flower pot was the inspiration for [Tom’s] own project. But [Tom] added in PID hardware to smoke at just the right temperature.
The enclosure hides a single electric burner at the bottom. A metal tray full of wood chips sits on top of it, smoldering as the burner gets hot. You could just set it and forget it, but it will take a lot of trial and error to figure out which setting achieves the best results. [Tom’s] additional hardware, housed in the grey electrical box, switches the burner with a solid state relay. The PID controller takes measurements from a temperature sensor inserted in the lid of the smoker, ensuring perfectly prepared food every time.
[Matt] noticed an overabundance of sous vide builds in the past week, so he decided to throw his Home made meat smoker into the ring. There’s not many things more delicious than a nice cut of smoked meat, and the fact that it’s very similar to the sous vide hacks we’ve seen is an added bonus.
[Matt] decided to build a ceramic smoker like a Big Green Egg. He took a cue from [Alton Brown] and used two terracotta planters and a hot plate for the smoker. For controlling the hot plate, the cheap $35 PID controller we’ve seen in a few sous vide builds was used. The PID can’t control the 7 amps of AC that the hot plate needs, so [Matt] used a solid-state relay he had lying around.
A stainless steel mixing bowl was placed on the hot plate for wood chips. So far, [Matt] has run his smoker for more than 12 consecutive hours, and the results are really promising – there wasn’t much change in temperature between the chill of the morning and the heat of afternoon. [Matt]’s build is great and perfect for venison jerky now that deer season is coming up.
If you’re going to freeze your butt off smoking in the middle of winter you might was well have company while you’re out there. [Zach’s] company wanted to crunch some data about smoking breaks and worker productivity. Instead of just meeting the bland data collection needs he decided to add functionality.
He took time to explain the different parts of the system. Above you can see the web interface that lets you know which of your coworkers are smoking right now. It also lets you click to check in and out from your breaks. After this was up and running he found that often the smokers forgot to ‘clock out’ before a break. As a backup system he build a physical interface on the way out of the office. Each smoker has their own button with a corresponding LED. If the light’s on you’re having a break and when it’s off you’re working. This controller is Arduino based and uses a Perl script to monitor the input and sync both that physical display and the web interface. [Zach] posted a few pictures if you want to take a look at the rest of the system.
Bradley smokers are coveted for their ease of use, as they require very little interaction from the user once the hopper is loaded with wood pucks and the machine is powered on. The more robust models are quite pricey, so [Maukka] decided to build his own version of a Bradley smoker as an add on to his existing unit. He fabricated a smoke generator out of aluminum, including all of the components you would normally find in an automated smoker. Once the hopper is loaded with wood pucks, the smoker runs autonomously, shuffling new pucks onto the heating element, presumably at timed intervals. The main barrel of the smoker has a separate PIC-controlled heating element installed, and is connected to the smoke generator by an aluminum duct. This configuration allows [Maukka] to cold smoke items such as fish, nuts, and cheeses using the smoke generator by itself, while also permitting the smoking of meats at far higher temperatures when the main heating element is used. This is truly a fantastic build, and the cold smoker component is something I would love to have as an addition to my Weber bullet.
Be sure to explore his blog a bit to catch all of the build details, as they are separated into various posts.