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I used a PID (proportional–integral–derivative) controller to regulate the temperature of my espresso maker. I wrote about it in my book, Made by Hand: My Adventures in the World of Do-It-Yourself. (You can read an except from the chapter on Gizmodo.)

PIDs are often used in Sous Vide cookers, too. (Here’s how to make one). If you are looking for a reasonably priced PID controller, here’s a new source: Brett Beauregard’s open source PID controller, for $85.

Brett’s pal, 3ric Johanson (author of Beam Weapon for Bad Bugs in Make Vol 23), says:

My friend Brett Beauregard has been working on this sweet open source PID controller.. and he’s finally published information online about it here.

A PID (proportional–integral–derivative) controller is a device which use hardware feedback with an algorithm; this allows the operator to maintain a target value (temp). Cruise control in car is the classic example: Set it at 60mph, and it will increase the accelerator until you hit 60. There are all sorts of things which can go wrong with closed-loop control systems – – overshoot, ringing, bias, etc. As this device is all open source, as it will make debugging these devices much easier.

It’s currently on “presale” for $85. I think this is a sweet deal. If you want to make your own Sous-vide cooker, this is the ticket. Go buy one, as I want to make sure this type of hardware is available to the masses. I’m excited to get mine.

Mark Frauenfelder

Mark Frauenfelder

Mark Frauenfelder is the editor-in-chief of Make magazine, and the founder of the popular Boing Boing blog.

  • Matt Lohafer

    With a tougher enclosure, this looks like it would be a great controller to run an electric casting furnace, or heat-treat oven.

  • restifo

    would be great for any lab. I run the pilot lab at my company, and we
    pay about $600 for a Honeywell controller. Granted, you get all types of
    certifications and a good enclosure for that, but this open source PID
    unit would be fantastic for a lab or R&D place. I could actually
    hack/program it to have several different configurations, depending on different types of tests we can run on different test units. Plus I could link several units up and have a master unit record data and act as the HMI. All at a fraction of the cost of a traditional unit.(For “real” process control, I’d still stick with brand name industrial vendors.)


  • Anonymous

    Well, “reasonably priced” is all relative and a matter of personal judgment. Personally I think $85 is outrageous. A standard industrial type PID controller can be bought for about 1/4 the price here :

    • restifo

      If you just want a simple PID that does exactly what the model is designed to do (specific output, alarm type, etc.), then, yeah, I’d agree you can get a unit cheaper.

      If you want something that’s highly configurable and hackable, then $85 is fairly cheap. Plus, you can design your own input board for specialized situations.

  • Joseph Pitz

    I agree, DIY and open source is cool, but when there are professional models cheaper that save you money for other DIY projects, that make sense.  I purchased my for around  $36.00,

  • qwerty123

    Making a beefed up and modular sous vide rig now off of the earlier Make article.  Got a CD101 for $33 at Lightobject.  While cool, $85 puts it into “nice to know” territory.

  • br3ttb

    Hi Everyone, I wanted to post a quick note to address the “outrageous” $85 price. if you’re looking for a barebones YMMV controller, you can definitely get a cheaper one.  There was just no way as a kit maker I could get the price that low. 

    Instead I tried to make this thing as over-the-top-functional as possible.  for example, not mentioned in the post is java configuration/trending app that lets you see trends of the current controller values.  VERY useful, and not something you would get with a $33 PID controller.

    here’s a video I did comparing the osPID to commercial PID controllers:

    and there’s a bit more information on my personal blog:


    • p07gbar

      Although I agree it has loads of features that the cheap commercial ones don’t it lacks a couple of bits they *do*, namely the case: the one you have designed seems a might hard to actually put into a project, and would probably benefit from a front panel (just sayin’). Also, although the PC software is nice, as an open source project, that kind of thing is pretty taken for granted, especially as all of that stuff is pretty much arduino stock… Which takes me on to the price: People want to use this for things like sous vide control: which means it has to be cheap, as that kind of thing is in the “just messing about” price category: sure if one was making something more serious, something more pricey would be perfect, but then making it ones self might be more suitable for them… And they might want to be able to mount it…
      Anyway, saying this, its a really cool board… I think something like this could be a cool “generic interface” too, not just for temp control, partly because of its tiny size and open source nature :)

  • PW

    This thing isn’t just limited to basic PID. By the time you buy an Arduino board, input/Outputs, a display and functional monitoring software the price point seems reasonable. And you get it in a nice sexy case. Comparing this to the other PIDs is definitely valid since it’s being sold as a PID, But it seems very capable and can make the jump from simple PID to DIY version of things like:

    BBQ Guru
    Brewer Control System

    Much easier for a novice tinkering engineer wannabe
    Which is why I am interested in this, some of the work seems already done at a decent price point.

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