Automated Coffee Bean Roaster


We’ve featured several different ways to roast coffee beans over the years. This is the next logical step. [Nightlife31] shows us how to use an Arduino and a popcorn popper to create a fully automated coffee bean roaster.  You’ll have to modify your popcorn machine to be controllable. This means installing your temp sensor and relays. You can see a basic schematic for that in the project page. The rest involves making a fairly simple circuit on an Arduino protoboard attachment. The end result is quite nice. We wouldn’t mind waking up to some freshly roasted coffee beans in the morning. We’ve seen these done with PID controls,  and directly controlled by a computer. There’s even this one that has a much more involved build with a convection oven mounted on top instead of a popcorn popper.

29 thoughts on “Automated Coffee Bean Roaster

  1. temperature as a metric would only be good per a ‘lot’ of beans, if it was able to spot second crack (via audio?) then cool properly –then this would rock!

    BTW- don’t roast in you house, you will regret it. It’s not dangerous, just smelly and smoky.

    1. I used to help do a little IT and Graphic design for a local coffee roaster. I don’t know what they were roasting, but it smelled really good. Well, for short periods. It was pretty strong and would probably get obnoxious after a while.

  2. “We wouldn’t mind waking up to some freshly roasted coffee beans in the morning.”

    Freshly roasted coffee beans are supposed to sit out in the open for 12-24hrs to let the beans release CO2. After that, they’re fair game.

  3. @Caleb

    Um, You are censoring Hack a Day viewers comments based on your view. This is basically the definition of denying freedom of speech. Why would you want to do that? Your visitors are telling you the content that they want to see, free of charge. Businesses spend tons of money trying to get feedback from customers. Perhaps it’s not so silly after all.

    Having said that, I am not an Arduino hater. They have their place. But, People will be divided on this just like the PIC/AVR battle.

    Listen to the readers or you might not have to worry about the anti-Arduino comments any more.

    1. @pete,
      We delete spam too, is that infringing on their rights? no.

      I’m not going to debate this any further. Like any site(or forum), we’ll do what we can to keep it on topic. Got a problem with how this roaster is built? got ideas to improve it? Let’s hear it.

      Let’s compromise, I’ll start an Arduino venting post in the near future so people can give some actual input instead of hijacking threads just to bash it.

  4. This looks really interesting and something I’d love to try.

    I learned something – that coffee beans need a rest after roasting.

    I for one am happy not to read the arduino jokes which stopped being funny 6 months ago, or hating which is completely pointless. This is an interesting post, why some of you try to attack topic of the the post out of mindless hhabit? It is really counter productive to the atmosphere of the site.

  5. @James
    Arduinos are good for getting something up and running quickly. Like the Halloween costumes with the street signal and the robot costume with feedback for the candy input that we have seen floating around recently – awesome.

    I doubt the author of this “hack” will give up coffee anytime soon, thus an arduino is not the right tool for the job. A purpose built circuit and a well documented write up is what is needed here.

    Arduino should be a stepping stone and not the end all be all to embedded programming or “physical computing” as some call it.

    A lot of very smart people work with arduinos and the developers/library coders too. Just know when to use one and when to do some real EE.

  6. lol @ pete and therian…

    Anyway, I don’t like coffee at all, and the whole roasting thing is completely new info.

    “Ooh, let’s make some popcorn!”
    “Unless you like coffee flavored popcorn, I wouldn’t advise it.”

  7. The picture shown there makes this look like it is a proof of concept design. The LCD is ribbon-ed into a breadboard. So I’m betting that if it works well it will get at least cased, or the main processor changed out for a smaller more frugal one.

  8. @Caleb

    Thank you for “Moderating” the YouTube posts. Freedom of speech belongs to the person who owns the press. Doesn’t take much to set up a WordPress Blog if anyone out there thinks they need more freedom.

  9. OMG someone’s deleting annoying posts that are repeated in every thread that has an arduino.

    STFU already. I’m glad he’s deleting your god damn whiney posts.

    And another clue from the clue bat that you all need hit up side the head with:

    You have no right to freedom of speech here. None. Zilch. Nada. Zero. Absolfuckinglutely nothing.

    Thank you Caleb, keep deleting these idiots.

    Nice Hack btw. I might make one for the gf.

  10. A little moderating here is okay in my opinion. Making newbies feel like they picked the wrong microcontroller platform is bad for the hobby. Its the old Ford vs. Chevy bench racing.
    P.S. Nightlife 31: Thanks for sharing your project.

  11. Censorship paranoiacs, calm down. We are all guests here, and the Hack a Day guys’ exercising their property rights has nothing, absolutely nothing to do with restricting someone’s freedom of speech. This is just as silly as entering someone’s private home, exploding a stink bomb, and then complaining about someone opening the windows. Not an Arduino user myself, it makes me happy to see that this platform serves as an inspiration for so many projects ranging vom below trivial to absolutely mindboggling, and I am looking forward to seeing lots more of them in the future.

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