Deeg

No, and I wouldn't recommend it as you run the risk of getting paint chips into your food. They only reason you'd want to paint the interior would be to cover something up but if there's something inside the drum you wouldn't want to use it anyway. Even homemade BBQ isn't worth poisoning yourself over. :)

The problem is almost certainly that you don't have enough oxygen getting to the coals. 4 holes at the bottom should be plenty, though. A couple of things to try:1) Assuming you have a lid, try cracking it open a bit more to see if you can increase the air flow. The holes at the top may be limiting the flow.2) Are the air holes on the bottom below the coals? They don't have to be directly below but they must have a lower elevation; otherwise the oxygen comes in the bottom and flows up OVER the coals instead of through them. This will limit the heat.If you want, send me a picture and I'll see if I notice anything.

The full-sized original is here: https://www.instructables.com/file/FGVWJ6PI155VXFL/?size=ORIGINAL. That should be big enough :)

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: https://www.kickstarter.com/projects/589069780/multi-use-temperature-controller-for-sous-vide-smo?ref=user_menu

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.

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: https://github.com/DeegC/UTC . You can track the project and make suggestions here: https://github.com/DeegC/UTC/issues/1

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

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.https://sourceforge.net/projects/udssupervisor/files/?source=navbar

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. ;)

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 SSR...

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.

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. (https://getchip.com/pages/chip) 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.