Introduction: Tweeting, Wireless, Ugly Drum Smoker (UDS) Temperature Controller Using Android

(Last updated: Oct. 2014. See last step for details on changes.)

This is the UDS Digital Supervisor, an Android app and hardware for remotely maintaining the temperature of your UDS like a thermostat. Your phone monitors the temperatures inside the UDS and adjusts a blower to keep the temperature to the setting you decide. Don't have a UDS? You can build one yourself!

What cool stuff can the UDS Digital Supervisor do?

The Supervisor app has the following functionality:

  • Maintains a constant temperature inside your smoker (duh).
  • Sounds an alarm if a thermometer temperature falls outside a configurable range. Very handy for overnight cooks so you can sleep worry-free.
  • Records the temperatures in a database and displays a graphical chart showing the progress of your cook.
  • Periodically tweets the status of your smoker so you can monitor your cook from anywhere in the world. Requires an internet connection (double duh). If you need something to put yourself to sleep you can follow my smoker's twitter account.
  • A companion app running on another Android device can monitor the Twitter feed and sound an alarm if there is an error. Go see a movie in peace knowing that your smoker is purring like a kitten in a basket full of warm socks.
  • Can monitor up to eight thermometers and measures in Fahrenheit, Celsius, or Kelvin.

How It Works

The app monitors the temperature using thermometers inside your smoker and compares it to your target temperature. If the temperature is too low the app will turn on a blower to force more air into the UDS, which will stoke the coals and increase the temperature. The app uses a PID algorithm to determine when to turn on the blower. Your phone uses Bluetooth to communicate with the hardware attached to the blower and the thermometers.


This project is made up of three main parts:

  1. Blower The temperature of the smoker is ultimately determined by the amount of air the coals get. The more air the blower pushes into the smoker the hotter it will get.
  2. IOIO controller The IOIO (pronounced yo-yo) is a microcontroller specially made for Android and acts as the connection between the blower/thermometers and the Android app. The blower and thermometers plug into the controller and it sends signals to your phone using Bluetooth. Check out the IOIO home page for more information.
  3. Android app The app monitors the thermometer temperatures and adjusts the blower speed accordingly by sending a signal to the IOIO controller. The app uses a PID algorithm to determine the correct blower speed. The temperatures and the blower speed are recorded in a DB (database) which can then be used to display a chart of the entire cook. The app is free to download and is Open Source, which means it will always be free.

Step 1: Parts and Supplies

Not including the Android device, you can expect to pay approximately $120 to build the controller and blower that you see here (this includes two Maverick thermometers). The battery I used is ~$40 but you can probably get away with a much cheaper option, especially if you don't plan on running 12-hour cooks.

Android Device

You'll need an Android phone. You do not need a cell or internet connection (unless you want to use the Twitter functionality) but it must have Bluetooth. This app should run on any 2.3.4+ Android device but I can't guarantee it will work until someone tries it. The following platform/OS combos have been tested. If you build one using a different combo let me know and I'll add it.

Device Android OS Version
Motorola Droid (original) 2.3.7
Samsung Galaxy S III 4.0.4
Motorola Droid 3Minimoto v1.7
Samsung Note 34.4.2
OnePlus One4.4.4
Nexus 74.4.2


Part Description Qty URL Price
IOIO This is the hardware that links your Android to the blower using Bluetooth. I used an older version of the IOIO but the new one should work fine. The main difference is that you need an adapter (supplied) to connect the Bluetooth dongle. If you don't want to use the new one you can get the older version on ebay. 1SparkFun $40
Bluetooth dongle The Bluetooth dongles proved to be tempermental. The two dongles linked here work but have a short range. See extended discussion later in this page. 1

Seeed Studio


Maverick ET-73 probes You want at least two probes, one for the pit temperature and one for the food. The pit probe looks different from the food probe so look at the pictures above to get one of each.

Be sure to get ET-73 probes, not ET-732 probes. They have slightly different plugs and are not compatible.
2+, max of 6 Search Amazon and Ebay $10-15 each
2.50mm mono jacks 2.50mm mono female jacks for connecting the thermometers. You need one per thermometer. I bought one jack in a different color to indicate which one is the pit thermometer. MultipleDigiKey
$1 each
Standoffs For attaching the IOIO to the enclosure. Any standoffs will do as long as the screws for attaching the IOIO fit through them. 4All-Electronics $0.40 for 10
3.5mm stereo jack Used to connect power between the IOIO board and the blower. Another one is required for the blower.(listed below) 1All-Electronics 1*
All-Electronics 2
3.5mm male stereo cable Used to connect the IOIO to the blower. A 3' cable is fine. 1All-Electronics $1.50
2.1MM power jack Double-check to make sure it fits with whatever power supply you buy. 1All-Electronics
TIP41C Switching transistor for controlling the blower via PWM. 1Digi-Key $1
1N4004 diode Protects the IOIO electronics from blower. 1All-Electronics
#4-40 screws + nuts Attaches the IOIO to the enclosure. Half-inch screws are just barely long enough so longer ones might be good. 4 Local hardware $5
Breadboard I soldered all the components to a breadboard that I bought at a local electronics supply. The one linked to the right should work although you may need to trim it down. 1All-Electronics $5-10
22.1k ohm resistors One needed for each thermometer. It would be a good idea to get twice as many as needed and measure them with a multimeter. The closer they are to 22.1k ohm the more accurate the measured temperature will be. Don't obsess about it: being off by 100-200 ohms is fine. MultipleAll-Electronics
$0.10 each
830 ohm resistor Part of the PWM circuitry. 1All-Electronics $0.50
Enclosure You can use any enclosure that will hold the IOIO and parts. I used a food storage container from the Container Store. A clear plastic box not only looks cool but lets you see the LEDs to verify that your IOIO is powered and working. Electric project boxes might not work as well--they have slots on the interior that make it harder to install panel-mount components. 1The Container Store $5
Headers I soldered headers to the IOIO. This allowed the breadboard (with the Arduino headers) to be plugged into the IOIO instead of soldered directly.Digi-Key $2.50
Arduino Headers I used Aurduino headers to connect the circuit board to the IOIO. Arduino headers have a longer pin. This let me replace the circuit board or the IOIO without having to unsolder anything. 1 pkgAll-Electronics $1.50
Total price w/ two thermometers (including optional headers) $100-$110

* - The first jack from All-Electronics is the jack I used. However, the second one is probably easier to use.

Power Supply

There are a few options for supplying power:


Using a battery for power means you can use your controller anywhere, which is convenient. I use a 10 amp-hour sealed lead-acid battery because I want to be able to run the smoker for 10-12 hours. This appears to be much more power than necessary because the battery hardly drained after 8 hours, so you may be able to get by with something cheaper.

Part Description Qty URL Price
12 volt battery 10 amp-hour battery 1RadioShack
Battery charger You'll need a charger if you use the battery above. 1RadioShack
Alligator clips Alligator clips to connect the cable to the battery leads. 2 (one pair)All-Electronics
Power plug Power plug for connecting battery to the controller. 1All-Electronics
Rectifier diode (Optional) If you follow my build then it's possible to accidentally reverse the polarity when you hook up the battery, which will fry your IOIO. A rectifying diode will prevent this at the cost of a bit of voltage. A 1-amp diode such as the 1N4007 should do. 1All-Electronics
Total price $40

AC Power adaptor (i.e. wall-wart)

You can buy an AC adaptor but you can probably find one at a thrift shop for cheap. The one I used for testing was a power supply from an old laptop that I bought for 50 cents. You can use any adaptor as long as:

  • It's 12 volts.
  • At least 1 amp. More amps is fine. If you want to be overly anal get one that can supply 2 amps. When the blower starts up it will momentarily take more power.

If you still want to buy an adaptor:

Part Description Qty URL Price
12v adaptor 12 volt / 1amp adaptor 1All-Electronics

Cigarette 12 volt adaptor

One other option is to use a 12-volt adaptor that fits into the cigarette lighter of your car. I haven't tried it but it should work fine.

Blue Tooth Dongle

The IOIO can be persnickety on what dongle it will accept. The IOIO has a dongle page that lists dongles that have been shown to work with the IOIO but it varies by phone and you may have to purchase multiple dongles before you find one that works with your setup. DealExtreme has lots of dongles cheap but they can take 4-5 weeks to ship. The dongles linked in the list above are known to work with the phones I've used.

Class 1 dongles are better because those have a longer range but I haven't found one yet that works. If you do, send me a message so I can try it too.


These are the parts required for the blower assembly. The nipple that I used fits into the 1/2" ball valve on my smoker. You may have to adapt your blower to fit your smoker.

Part Description Qty URL Price
Enclosure Any enclosure that can house the blower and the PCB connection can be used. The one I used is linked here. 1All-Electronics
3.5mm stereo jack Used to connect the power cable from the controller. Another one is required for the controller. 1All-Electronics 1*
All-Electronics 2
12v blower The blower I used has a tachometer sensor which isn't currently being used. 1Digi-Key $14
M20 Washer M20 washer. I bought it at a local Ace Hardware. 1HomeDepot $0.60
Nipple 1/2 x 3 pipe nipple. 1HomeDepot $2
PVC bushing 3/4 x 1/2 PVC bushing. I had to cut off the end to get it to fit in my enclosure. 1HomeDepot $0.66
Screws + nuts For attaching the blower to the enclosure.
Total price $22


  • Drill and bits, preferably a drill press.
  • If you build a blower like the one above you'll need a drill bit for cutting 7/8" holes, like this one.
  • Soldering iron and solder.
  • X-Acto knife or similar.
  • Wire cutters, pliers, etc.

Not necessary but helpful:

  • Heat gun and shrink tubing to protect your wiring.

Skills Required

The most difficult skills for this project are soldering and the ability to read simple schematics. You'll likely need some patience, too. :)

Step 2: Power the IOIO and Pair the Bluetooth Dongle

Building Tips

Some advice and tips for building the Digital Supervisor:

  • Go slow and test test test at every stage. You don't want to be near completion only to realize you soldered a part wrong back in step 2.
  • It helps to use the headers instead of soldering the wires directly to the IOIO. This makes wiring mistakes temporary instead of permanent.

Attach Power Supply

  1. If you decide to use them, solder the headers along the long edges of the IOIO. When testing you can plug in wires like a breadboard.
  2. Solder two wires to your power jack. Attach the +/- wires from your jack to the VCC and GND pins on your IOIO and connect your 12v power supply. If you've done it correctly the red LED should light up. WARNING: If you reverse the polarity of the power supply then you WILL fry your IOIO. (Don't ask how I know this.)
  3. Disconnect the power and insert your Bluetooth dongle into the IOIO and reconnect. When the IOIO starts up it will put the dongle into discovery mode and you should be able to see it from your Android device. Pair them together using '4545' as the pass code. For more information see the IOIO Bluetooth page. If you have problems see the Trouble Shooting page in this Instructable.

Step 3: Install Software

Now install the UDS on your Android device. This allows you to test the Bluetooth connection between the IOIO and Android.

The app is not in the Google Play store; you have to download/install it yourself. The app can be found on the SourceForge site here. Download the latest .apk file to your phone. There are multiple ways to install the app on your Android phone:

  1. Download installer app from Google Play and use it to install .apk.
  2. Install app manually.

The first time you start the app it will take some time to unpack and start the database. Once that is done it should work without any long delay. To test press the "Start Supervisor" button. This will start up the supervisor service on Android and attempt to connect to the IOIO. If it works you should see something like the second screenshot shown above.

If Android has connected to the IOIO you should see a yellow light on the IOIO blinking four times a second. Since you haven't wired up any of the thermometers they should say "Not detected". If you see temperatures then you've had little fairies visit your home during the night. See the step later on for a quick primer on using the software.

You can download the source for the Digital Supervisor here and compile it yourself.

Step 4: Schematics and Wiring

Now comes the hard part: soldering and wiring the thermometer and power jacks to the IOIO. To make it easier I soldered the Arduino headers to the circuit board. The pins on the Arduino headers are longer and they fit snugly into the headers that are soldered on to the IOIO. See the pictures. When you insert the Arduino pins into the header on the IOIO make sure they line up correctly. You may have to trim your circuit board; if so leave some room on one end for holding the blower circuitry.

Start by adding the circuitry for one or two thermometers. When you have them wired up you can start the Supervisor and connect it to the IOIO. You should be able to correctly read the thermometers. Once they work add the wiring for the other thermometers. You should have at least two thermometers and can have a maximum of six. The "pit" thermometer is the one wired to pin 46; this is the one that the controller will use for matching to the target temperature. Pins 45-41 correspond to thermometers 2-6.

The Supervisor should display an accurate temperature for the thermometers. You can test the accuracy by dropping the thermometers in hot water and compare to another thermometer. If you don't have other thermometers, boil the water; the Supervisor should record temperatures of 212 degrees.

Step 5: Blower Assembly

Assembling the blower and housing is straight forward. It's easiest to drill all the holes in the lid for attaching the blower. Start by laying out everything in the lid to make sure they're evenly spaced and then drill away. Make sure you have the blower positioned so that it pulls air from the air holes.

The only thing to be concerned about is drilling too many holes for the air-intake. If there are too many holes then too much air will leak into the smoker even when the blower is off.

Step 6: Install IOIO Into Enclosure

You've tested everything and it works, right? Replacing/fixing the controller becomes harder once you've put it all in the box.

Put everything together in this order:

  1. Position the IOIO in the box and drill the holes on the bottom. When measuring the holes make sure you've left room for the other parts that you will install.
  2. Drill the holes for the thermometer jacks, the power cable, and the blower jack.
  3. Attach the IOIO with the spacers and screws.
  4. Insert all the plugs. This is easier if you don't have the circuit board plugged into the IOIO.
  5. Once all the peripherals are attached, plug in the circuit board.
  6. Lastly plug the wires into the circuit board.

Congratulations! The hardware should now all be done!

Step 7: Make Side Items

If you normally won't have a table near the smoker then make a holder for the controller. The one shown here is made from a piece of steel and some rare-earth magnets. Glue the magnets to the piece of metal and stick on felt furniture pads to the magnets.

Solder the alligator cips to a two-conductor wire with a power-jack on the other end. Use this for connecting the batter to the controller.

Step 8: Running the Software

This is a quick walk-through for using the Supervisor app:

Main Screen

Opening the Supervisor brings up the main screen. This is where you set the options for your smoker and start a session for controlling your smoker.

Start Supervisor - Press this button when you are ready to start a new session to control the temperature of your smoker.

Continue - This button will continue the previous Supervisor session. Use this if you stop a session to change a value (like the target temperature).

View Session - This button will show a list of all the smoker sessions you have started. See the View Sessions section for more.

Configurations - This is a drop-down box that allows you to select one of your configurations. The Supervisor is installed with a single configuration named "Default Config".

New - This will create a new configuration.

Config name - Name of the current configuration.

Number of Thermometers - The number of thermometers for this configuration.

Thermometer list - Each thermometer can be given a name here. Note: the first thermometer is always used as the pit thermometer regardless of its name. Turn on the checkbox if you want this thermometer to fire off an alarm if the temperature falls outside a range.

Main Settings

Access this screen from the Menu button on the Main screen. This allows the user to change lesser-used settings.

Record Temperatures - If on, then the temperatures will be saved to the database and can be charted later. If off, the session can not be viewed.

Tweet On - If checked, then peridically tweet the status of the smoker.

Tweet Rate - Specifies (in minutes) how often to tweet the status.

Twitter info - Twitter handle and passwords necessary for tweeting the status.

Run webserver - If on, then starting a session will start the web server to handle HTML requests.

Max Blower PWM - Set this value lower for larger and more powerful blowers.

PID settings - These are the PID settings for the PID Algorithm used by the Supervisor. Change these only if you know how to tune a PID controller.

Monitor Session Screen

This screen is displayed when the Supervisor is monitoring the smoker and controlling the blower. It displays the target temperature, the thermometers, and the blower speed.

Chart Session - Press to view a running chart of the current session.

To stop the current session, press the menu button and select "Stop Monitor".

Example of a temperature error:

Chart of smoking session

List of previous Sessions

This lists previous smoker sessions. Click a session to see the chart. Hold-click to delete a session.

Step 9: Tips and Trouble Shooting


Practice. It will take some practice to consistently set up the Supervisor at the right temperature. Practice a few times before you smoke anything important.

The hardest part is learning how to adjust the various vents on your smoker and blower. If they are open too much the temperatures will continue to go up even when the blower is off. If they are closed too much then the blower won't be able to push in enough air to maintain the target temperature. The adjustments will be different each time, depending on conditions like how much food you have in your smoker, the target temperature, and how windy it is.

If your smoker has vents on the lid it is easier to start by adjusting them first. If that doesn't give you enough control you can try adjusting the opening to the blower, for example by covering some holes with tape.

Starting the coals. Use the Minion Method. When you first put your lit coals in the smoker keep the blower disconnected from the intake pipe. This will allow lots of air into the smoker to get the coals going. When the temperatures are about 50 degrees below your desired temperature attach the blower and let the Supervisor take over.


Bluetooth dongle doesn't show up on Android's list of devices.

There's not much you can do except try another dongle. You could try to plug in the dongle to another device, pair it with Android, and then plug it into the iOIO.

Pit temperature goes way above the target temperature.

Two likely things that might be going wrong:

  1. You're lighting too many coals to start off.
  2. The vents on your smoker are open too much and they are allowing too much air into the smoker when the blower is off. Try closing down the vents. You may have to put some tape over the blower intake holes if you drilled too many (see picture above).

Pit temperature never reaches target temperature.

The problem is almost certainly the result of not enough oxygen to your coals. You may not have drilled enough holes into your blower enclosure or your blower may be too weak. Try a test by running your smoker withOUT the blower attached and all vents open. If the temperatures go higher than the problem is with your blower or its enclosure.

If temperatures don't go higher than the problem is more likely your smoker. Is the opening into your smoker too small?

Step 10: Updates

Updated schematic (Oct 2014)

The schematic showed the thermometers being connected to the wrong voltage pin. They should be connected to the 3.3v pin.

UDS version 1.1.0 (June 2014)

This change changed the DB schema and requires that any previous versions be uninstalled. This will unfortunately erase all current data.

  • Added Celsius and Kelvin as temperature unit options.
  • A chart of the cook will be attached to every 5 tweets (only if session is recording the data).
  • The Twitter Monitor will show the most recent chart.
  • Button to delete configurations.
  • 8 thermometers are supported.
  • Removed webserver functionality. Nobody was using it and it reduced the .apk file by 30%.
  • Some internal changes to prevent a new starting tweet if the screen was rotated.


Deeg made it!(author)2016-09-05

A couple of people have asked about how the new UDS is coming along. It's going slowly for now but I am working on it. The project is here: . You can track the project and make suggestions here:

tim_n made it!(author)2017-01-17

I like the idea of a Tweeting/Wireless UDS controller, but thinking of keeping it simple for a bit. I've seen a lot of people recommending auber controllers, is there any sensible reason not to use an STC-1000? Seems like it'd do the job just fine and the auber only goes to 160'F anyway... Difference in cost over here is £60 vs £10

Saying that, everything else I have is internet enabled and it does look like fun.

Deeg made it!(author)2016-11-23

For any who are interested I've created a Kickstarter project for creating the new version of the UDS that can run autonomously. You can see it here:

marcop82 made it!(author)2016-09-30

Thanks! If I buy a correct jack connector, can I use any maverick probe? I can't find ET-73.

Deeg made it!(author)2016-09-30

I can't guarantee it but I believe you can use any Maverick ET- probe if you use a jack that will pair with it. I was able to use the ET-732 in a test.

AdamC62 made it!(author)2016-07-16

Great instructable! Really glad you put this together Deeg. Used both of your UDS instructables to create the smoker and the controller.

I've been using the 2.0 beta of the software you put out and it's been working so far. Finally putting it to the real test today and have a boston butt on.

Something for anyone who's about to take this project on from scratch: The latest version of the IOIO now has this type of jack for the power input:

That link also lists the mating products. Personally, I just soldered my power connections but I don't really recommend it. It's surface mounted so the risk of damaging something is pretty high.

Also: If I were to do this again, I wouldn't use a soldered breadboard. I'd just use the poke and go type, like this:

AdamC62 made it!(author)2016-07-16

Another thing to mention: I'm bought the same battery as Deeg. I'm going to replace my gator clips with F2 terminals for a better connection.

bives1 made it!(author)2016-07-04

Hi Deeg,

First of all, great instructable, very detailed and looks like exactly what I'm after!

Secondly, I'm starting to order all of the parts to make this, the only piece I'm unsure about is the temperature probe, could you tell me if this one (link below) would work? I'm UK based so there's not exactly an abundance of cheap parts available for smokers and accessories, and I'm aware there's a subtle difference between probe jacks that means they might not fit correctly?

Thanks in advance.

Deeg made it!(author)2016-07-04

According to the Q&A for the thermometer it does NOT work with Maverick devices so it won't work with the UDS.

Deeg made it!(author)2016-06-30

For any of you who are interested, I've put up a new version of the UDS software that uses the now-standard Android menu items. It should work with all recent versions of Android. I have tested it with long cooks on both my Nexus 5x with Android 6.x and an older Nexus 7 with Android 5.x. The other major change is a fix for a long-standing bug with the alarms that caused a runaway CPU. It's currently "beta" but if nobody finds any problems I'll make it official.

haddad1 made it!(author)2016-06-08

Just found this in a box, it's my extra Tweeting UDS PCB shield that I created. Don't ask it's not for sale, plan on using it in a custom antique refrigerator smoker conversion.

Thanks again Deeg! I use my controller all the time and couldn't be happier. Use it mainly on my Bradley electric smoker but have used it as a stoker controller and to control a Sous-Vide system. Works great in all systems.

There are some more details in my previous posts about my device. it has 8 temp inputs and is setup to control a stoker fan or a heating element with the addition of a solid state relay.

The only things I might ask for is a second and third output. Second output would run at timed intervals for use with an auger or feeder mechanism. A third output could be used for circulating fan.

I have had a few requests from friends and family to make them a controller after seeing mine in action. Sadly the hard drive that held my schematic and PCB layout files crashed. Finding my spare board got me thinking I should recreate the board schematic and drawings. Then get some PCBs manufactured. Making them myself on my patio and drilling all of the holes is more than I want to do again. Is anyone interested in getting one if I have some extras made? I will post if and when I decide to have them made.

I can't thank you enough Deeg, this device is amazing!

16, 6:20 PM.jpg
Deeg made it!(author)2016-06-08

Hey haddad1, thanks for the kind words. :) It's nice to know that others are getting good use out of it. One of the things that I've always had in the back of my mind was to make it easier for people to build with a PCB. I have no experience with PCBs, though, and I just don't have the time to learn.

I would be interested, however, in building a UDSv2 using the C.H.I.P. ( if someone would be willing to put together a PCB schematic that anybody could use to have one made. The CHIP is cheaper than the IOIO, has built-in BT4.0 (and wifi), and could run autonomously. I've got a couple on pre-order that are supposed to arrive this month.

If that's something you'd be interested in let me know and we can discuss it.

haddad1 made it!(author)2016-06-20

id be glad to help with designing a PCB layout for the V2 using CHIP. after doing a little research, the CHIP looks like a good match. what are your plans on display and control of the chip? if your planning on using the LCD display pins, that will decrease our usable IO pins to only 8, and the dedicated PWM pin wouldn't be available as it would be used for the LCD back-light. i see that IO pins can be used as PWM but might not work as well according to the CHIP website..

"Pulse Width Modulation is used to control motors and other devices.
It is possible to use GPIO pins to drive motors, but they generally are not fast enough for robust and smooth control." quote from CHIP website."

looks like all i would need to get started is the IO pin assignments. ( what IO pins you want the probe inputs and control outputs connected to.) you could tell me what you want or i could assign them and let you know what they are. for me to assign them i would need to know if your planning in using the LCD connected to the CHIP pins.

i assume that you plan on designing it around the current IOIO schematic. (same resistor sizes and probes?)

my thoughts on the new PCB are to have everything mounted on board for a clean and easy assembly(assuming the builder has basic soldering experience). it would also include a PCB mounted switching power supply for converting AC line voltage to 12VDC and 5VDC to eliminate the external wall-wart power supply. another option would be a 12VDC power supply and a separate 5 volt regulator circuit. this would allow you to use a battery to power the device in the event that there is not AC power available. (note that the chip does not have a 5VDC regulator to step 12VDC down to 5VDC.) also included would be a place to solder in 1 or 2 SSR relays to control heating elements and other high power loads. the SSRs would be optional parts and would not be required to operate in the normal mode that you originally designed the device for.

what are the chances of adding a circulating fan output and feeder control output?

i will start working on recreating my IOIO schematic, should be able to convert it to CHIP easily after that.

Deeg made it!(author)2016-06-23

To keep construction as simple as possible I think we should skip the LCD screen. Maybe we should add some LEDs to indicate that the UDS is on, that it's running the PID, and when the PWM is on, etc.

I like your ideas about the power supply. I'm concerned that 5V isn't enough to run a fan so I think 12V input is smart, which means we need the regulator. Assuming I understand what you want, adding additional outputs that can be turned on/off via the app is relatively simple. Other than those changes we might as well duplicate the current schematic.

Regarding the SSRs, I have no problem with adding them to the PCB but I was thinking of a more modular design: an external SSR that plugged into the controller via the 1/8" jack. That would allow users to plug in different types of SSRs depending on the application. For example, I'd use the 12V PWM to run a fan directly (like the UDS currently does) but another time I could plug in an SSR with an outlet to run a crock pot (similar to my DIY sous vide Instructable). The controller could then be a truly universal temperature controller that could moderate almost anything. That said, I'll go along with whatever the majority wants.

Lastly, if I write the software correctly then it could work with Android, iPhone, or Windows. Someone else will have to write the iPhone and Windows code, though.

haddad1 made it!(author)2016-06-27

i just placed an order for 3 boards through OSH Park based on the original design for IOIO.

haddad1 made it!(author)2016-06-28

Had a thought about using the CHIP. How would we connect the chip to wifi networks, I use mine at multiple locations? Having to hookup monitor mouse and keyboard every time I move it, would get annoying. And what about when no networks are available such as at a cook-off?

Deeg made it!(author)2016-06-28

My current plan is to use Bluetooth as the main connection with the CHIP (which has built-in BT 4.0). The mobile app would largely be just a UI that changed the settings on the CHIP. The wifi would only be used at runtime for tweeting.

I've never written a BT app (the beauty of the IOIO is that it handled all that) so we'll see how it goes. ;)

brbeardm made it!(author)2016-06-15

haddad1, I'd be interested in a few PCBs with the extra outputs you describe. I'd like to use a CHIP to control everything for a pellet grill assembly and connect via WiFi to my phone so I could control the cook from anywhere!

elnino2783 made it!(author)2016-06-02

Now that 3 years have passed since creating this, do you think there might be a cheaper way of making this?

The sensors seem like the only area where money couldn't be saved because costs are about the same.

I was thinking maybe an ESP8266 module for at least basic functionality, and then an arduino or similar to handle the other more advanced functions.

That's all hypothetical, though, because I haven't built anything with either.

Deeg made it!(author)2016-06-02

The ESP8266 would be a possibility; it has all the requirements (e.g. connectivity and PWM) and wouldn't require an Arduino. Unlike the IOIO it might also be able to run autonomously. The downside is that it's harder to program. The C.H.I.P. might be a better option since it would be much easier to program (for me, anyway) and could definitely run autonomously. Since my current solution is working I'm not that motivated to make a new one. (I am, however, updating the software; there's a UDS 2.0 beta available.)

However, I'd be willing to work on a new one with ESP8266 or C.H.I.P. if someone was willing to create a PCB that would make the physical construction easier. I find soldering all the pieces together to be tedious. :)

john1tx20 made it!(author)2016-04-24

Deeg, yes, the fan cycles on and off. Also I must restart the phone to exit the app. John

Deeg made it!(author)2016-04-28

John, I've put up a beta version of UDS 2.0 that you can try. It works on my Nexus 5x with 6.0.1. Let me know if you have any problems.

john1tx20 made it!(author)2016-05-01

Deeg, The beta version will not run. When I try to start it the following message appears "Unfortunately, UDS Digital Supervisor has stopped." John

Deeg made it!(author)2016-05-01

Can you send me the logcat? I'll give you my email via PM.

Deeg made it!(author)2016-04-24

Thanks for the info John. I'll try to look into it this week but then I go on vacation for a while. I'll let you know when I have a new beta version you can try.

john1tx20 made it!(author)2016-04-23

Deeg, Finally completed this project. Going to try the UDS tomorrow. The fan cycles on and off. Also the fan speed does not show on the app. Phone is HTC 6525LVW with Ardriod 6.0. Thanks, John

Deeg made it!(author)2016-04-23

John, do you mean the fan just turns off and on but doesn't adjust its speed? I'm in the process of updating the UI to work with Android 6.0 and I noticed the fan speed bug. I'll try to fix it soon. Let me know if you run into any other problems.

mr+gem made it!(author)2016-01-04

Hey Deeg hallo again! how did i missed that post and i spent money buying maveric .... ! How accurate are the thermometers? Very nice post very nice project for this year!

Deeg made it!(author)2016-01-04

When I did a test a while back the pit thermometer was within 2 degrees F. When I have 6 thermometers plugged in they are all within 5 degrees F, plenty good enough for smoking. :)

mr+gem made it!(author)2016-01-05

Yeap ... dont think that will make any big diversions!

Dont laugh with my question ! i dont know nothing about electronics but it would be a good idea to put a LCD display! or its not possible?!?!

Deeg made it!(author)2016-01-05

It wouldn't be easy to add an LCD screen with the current construction. The IOIO can attach to an LCD but the wiring would have to be re-configured. I'd be happy to help re-write the software if someone wanted to do this but I don't have the desire to do the re-wiring for the screen.

MichaelL98 made it!(author)2015-09-04

I built one today, using a nexus 5, and for some reason, my temp comes and goes, like every 2 seconds, any idea's?

MichaelL98 made it!(author)2015-09-05

Was the blue tooth, thanks

Deeg made it!(author)2015-09-04

I assume what you mean is that the display vacillates between showing a temp and "NA". Is it doing it for all thermometers or just one? If all thermometers are showing NA then the connection between your Nexus and the IOIO is dropping. If it's just one then you probably have a loose wire connecting the thermometer.

Have you looked at the logcat? That should show if your connection is getting dropped.

Deeg made it!(author)2015-09-05

If you have the Android development kit installed you can download the logcat off your phone using adb. See here:

There's also a free app called aLogcat you can install to see it.

CivB made it!(author)2015-07-19


I've just stumbled across this whilst looking for a way to automate my UDS using an Arduino or the HeaterMeter. I love what you've done, it's so much simpler and is definitely cheaper.

I was wondering if the webserver you removed in the latest version of the apk allowed the settings to be altered remotely? I realise I can get status updates by monitoring the twitter feed (do you have a preferred app for this out of curiosity?), however I'm hoping to be able to alter settings mid cook remotely as varying recipes may require.

Anyway thanks for the great work you've done already, it's much appreciated. As a novice to the UDS scene (it's only growing in Australia) I'm keen to learn how I can get the most out of it.

haddad1 made it!(author)2015-08-12

if you are using a rooted android device you can use an app called webkey to remotely control it.

Deeg made it!(author)2015-07-19

Thanks for the comments CivB :)

I never got the webserver working more than just returning the current temperature before turning to Twitter instead. My initial plan was to accommodate changing the target temperature but I've never needed it. Pretty much everything I cook is done at a steady temperature and most BBQers do the same. If there is enough demand for it I can look into it. I'd probably implement it via Twitter.

I added some functionality to the UDS to monitor the twitter feed (I see that I haven't updated the documentation; it's under the "Menu" button on the main page). It will monitor the feed and display the most recent message and temperature chart. It will sound an alarm if there hasn't been a tweet in 20 minutes or if the UDS notices an error with the temperatures. I use it on all my overnight cooks to warn me that something is wrong.

dmeans-1 made it!(author)2015-05-31

I think that s so cool but can i use my samsung not 4

author made it!(author)2015-04-30

Could somebody please post a detailed picture of the Stereo Jack wiring? Everything works fine so far (power supply, temperature in app with sony experia)

I'm unsure how to connect the powerjack with the 825k transistor TIP41C and D11N4001 in the right way. In most pictures, this part is not clear to see

Photo 30.04.15 14 59 44.jpg
author made it!(author)2015-03-26

I'm having trouble finding a 830ohm resistor in germany

the link doesn't give away much information besides

825ohm 5watt resistor (which is confusing, 825 or 830?)

Deeg made it!(author)2015-03-31

Hmmm...looks like allelectronics has updated their web site and the original link doesn't work any more. I'll fix that some day. Any resistor ~830 ohms will work fine. You can order the 820 1/4-watt resistor from this page:

simon.czyzewski.5 made it!(author)2015-01-11

Great project I will be making one but I am wondering do you think it would be possible to use a wifi dongle instead of bluetooth ?

Deeg made it!(author)2015-01-11

The project as constructed must use a bluetooth dongle. The IOIO doesn't support wifi that I know of and even if it did the code would have to be rewritten.

g00se_is_l00se made it!(author)2014-11-13

hey i installed the new version you put up the 1.2 but how do i get to the settings now my action menu button part were i could get to settings before is gone?

Deeg made it!(author)2014-11-13

The settings UI hasn't changed so it should work the same as before. At least one other person has used 1.2 and didn't mention any problems with the UI. If you still have problems send me a PM and I'll give you my email so you can send me the logcat.

I just put up a new version of 1.2 with some bug fixes so you may want to try that.

g00se_is_l00se made it!(author)2014-11-23

I feel like i am missing something about how to get to the settings. It use to be in the bottom right corner now its no longer there and i dont know how to get there to access the twitter settings.

g00se_is_l00se made it!(author)2014-11-03

I'm having trouble setting up the twitter part do i put the @xxxx or just my twitter account name like xxx and i have the api key and api secret access token and token secret but i cant seem to get it to tweet. There isn't much on instructions on setting up the twitter part. Do I need to do more on the account or is it suppost to be as simple as plug in token secret tokent api key and secret api key?

sascharr made it!(author)2014-11-14

I have the same problem, what is mean with api key and api secret access token and token secret?

g00se_is_l00se made it!(author)2014-11-18

How do i get to the action button on the new andriod 4 were it use to come up and say settings when i was using my tablet its andriod 3 were all the twitter info goes? Its no longer gives me the option on the 1.2 vesrion to access it like this?

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More by Deeg:Memom's apple pie with simple DIY crustTea Light for Two -- make your own pendant light from a tea setUgly Drum Smoker (UDS) How-to and FAQ
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