The most advanced microwave you’ll ever own

raspberry-pi-microwave

Voice activation, one-touch cooking, web controls, cooking settings based on UPC… have you ever seen a microwave with all of these features? We sure haven’t. We thought it was nice that ours have a reheat button with three different settings. But holy crap, what if you could actually program your microwave to the exact settings of your choice? You can, if you let a Raspberry Pi do the cooking.

This hack run deep and results in a final product with a high WAF. Nathan started by taking apart his old microwave. He took pictures of the flexible sheets that make up the control button matrix in order to reverse engineer their design. This led him to etch his own circuit board to hook the inputs up to a Raspberry Pi board and take command of all the appliance’s other hardware. Because it also drives the seven segment display you’ll never see the wrong time on this appliance again. It’s set based on NTP.

We mentioned you can tweak settings for a specific food. The best way of doing this is shown in the demo video. The web interface is used to program the settings. Recalling them is as simple as using the barcode reader to scan the UPC. Amazing.

Now you can keep that old microwave working, rather than just scraping it for parts.

[Thanks Tom]

Comments

  1. Sven says:

    Lies! Someone with the equipment to do all at home simply does not have a wife :P

  2. kieldanger says:

    It needs an “Earl Grey, hot” setting.

  3. Quinn Dunki says:

    s/wife/spouse

    There, fixed that for you. See how easy it is to not be sexist?

  4. Chris C. says:

    Fancy! Wonder what material the overlay is made from.

    If there’s one thing I’d change about my microwave, it’s that at power levels <100%, the PWM seems to be synchronized nearly to the carousel rotation. So it always heats the food at the same rotational position, which doesn't provide very even heating.

    • echodelta says:

      Agreed. The “dimmer” in a microwave is a flasher, on off… useless when the total cook time is short. I never use those settings.
      Voice activated a plus, just look at the filthy controls in any kitchen. Prep of meat needs no touching anything else until washing hands.

  5. Luke says:

    A microwave oven should have two dials and a button: one for time, one for power, and a button to start/pause cooking.

    If we want to get fancy, then we can add a button to add the dialed-in time and power settings to a list that the microwave follows sequentially, a button to clear said list, and a display to show you the list.

    Any more than that is needless fluff and has no place on an appliance. No easy-start BS, no instant +1 minute button, no preprogrammed cooking schedules.

    • v says:

      Yeah, sure, and a cell phone should have two options: to call people and send text messages. Everything else, like stopwatch, notes, alarm clock, not to mention games or accessing the Internet is needless stuff and has no place on an appliance.

      Dude, why you use a computer at all?

      • JB says:

        Dude, it is a cell PHONE. It is made only to make and receive calls. EVERYTHING ELSE is fluff :P

      • Luke says:

        I wasn’t aware computers had anything to do with microwave ovens. I was under the impression that one is a general purpose computation device, doing whatever it was programmed to do, and the other is there to quickly heat up your food.

        I suppose I worded my first comment very poorly. Mostly, I’m wondering why mods always add functionality, rather than strip away cruft for clarity’s sake.

        I mean, okay, the web interface is cool. But do you really need 3 different buttons that all add 10 seconds to your cook time, among multiple similar buttons for other time settings?

        • Eirinn says:

          woooosh oveyour head :P

          • Luke says:

            Not at all over my head. I just didn’t feel like addressing every last one of V’s points, so I went for the low hanging fruit. Apples and oranges…

            For the record, I find myself mostly agreeing with his proposal of an ideal cell phone. Calling, contacts list, and maybe texting; all other features truly are superfluous gimmicks. Unfortunately such cellphones quickly went extinct as manufacturers scrambled to add a heap of bullshit multimedia features nobody sane ever used.

            Smartphones are a different story, as they’re general purpose computers that incidentally happen to be able to place phone calls.

            Perhaps you’re not following my reasoning here. Compare the upcoming Mac Pro to any project log on any modding site, and take a wild guess which I’d prefer.

    • Tony says:

      You don’t need the start button, and to be honest the power level knob isn’t needed either. No-one ever changes from 100%.

      That’s what the very first ovens had – one knob for the timer.

      You can get ovens with the two knobs like you say, see http://depositphotos.com/21557737/stock-photo-microwave-oven.html

      They’re not easy to find as most people buy on features – more features is good, right? (aka the point of this hack). I once had a microwave with a ‘reheat 1 slice of pizza’ button. Never used, along with the rest of the junk.

      • mosheen says:

        I use the power setting more than not. I usually cook at %50-70 with more time on the dial. You get even heating without burning your mouth off.

      • Luke says:

        Power settings are useful. Taking that away from a microwave would be like only putting frying pans on a burner at full blast.

        And the problems with simple microwave ovens are that they’re often of poorer quality, lower capacity, and kinda ugly, not to mention somewhat uncommon.

        The perfect microwave oven would be modeled after the Nest thermostat, in my opinion.

        • Tony says:

          Power settings aren’t really as useful as you think. 5 minutes @ 100% is the same as 10 minutes @ 50%.

          Still, having a knob to play with is fun.

          The best way is to do a couple minutes on 100%, check, a couple more on 100%, check etc. Once you’re happy with the result keep a note of how long it took, and do that next time.

          • Luke says:

            See that would hold true if microwaves heated food perfectly evenly, but they don’t in practice. They’re vastly better than microwave ovens 20 years ago, but unless you’re irradiating a perfect sphere from all angles simultaneously, there will always be some degree of unevenness.

            What that means for food is that if you have too high a heat setting for too long a time (and some foods require a fairly long time), some parts of your food will get that nasty dry-crunchy not-quite-burnt crusty stuff characteristic of microwave ovens. Sometimes, it’s better to wait patiently and nuke it longer at a lower setting.

            Furthermore, there’s a reason frozen foods often recommend having your food sit in a microwave oven for a minute or two after the timer completes: it’s still cooking in its own heat. So again, cooking slower at a lower setting helps heat food more evenly and gently.

  6. This would be ideal for my “Microwave superconductor” experiments.

  7. Kuy says:

    Amazing that *ANY* of that tech works reliably in the high RF field immediately outside the inner shielding – you can easily get several V/m around there. Moreover the Raspberry Pi is notoriously unstable in adverse power supply and E-field conditions (you can breathe on it and it can freeze – true story), it’s a miracle it works at all. #curmudgeon

    Love the project though – with tech like this at the disposal of hobbyists, it’s amazing that white-goods products don’t ship with any interesting or quality IoT features.

  8. zuul says:

    “hydrate level 4 please”

  9. Phoenix says:

    Barcode reading on microwaves has been around for quite a while. I won a contest over at woot probably 6 or 7 years ago and got one with a handheld scanner.

  10. Nunya Bidness says:

    I really don’t like the idea of a non-stock controller for my microwave.

    Microwaves are one of the most regulated items in your home. Sometimes., governmental oversight is not a bad thing.

    It’s like RC-ing a full size car. Fun, but dangerous.

    • Tony says:

      What regulations?

      There’s nothing special about a microwave oven that causes governments to invent a bunch of rules & regulations specifically for them.

      [Citation Needed] indeed.

    • mosheen says:

      The control electronics will have no effect on the safety of the device. As long as they are using the Rpi to just switch the stock relay on and off there is no difference.

      • Ike says:

        To make it possible to control a microwave over the internet is extremely dangerous. The problem is that I also see no possibilety to prohibit this and control such a regulation.
        Just think about it. If someone hacks your microwave over the internet and heats it a couple of hours. There goes your building. It is less with a fridge connected to the internet, but if I turn your fridge off and let it defrost when you left your home for a 2 weeks holiday, you could also repair your floor/ceiling.
        With terrorists and teenagers on the internet, I’m very against the connection of these appliances to the web.
        Just think of the dangers when you could regulate the heat of your microwave from another part of the world.

        • Kyle says:

          Just hard-code a cut-off in the raspberry pi so that if it’s set for something ridiculous or used too much over the web that it needs to be touched physically.

    • Paul says:

      Microwave radiation is non ionizing so it’s not too dangerous.

      • 0c says:

        Incorrect. Microwave radiation is fairly dangerous to humans and will fuck you up by causing deep burns (especially the eyes, leading to near instant blindness)

  11. Yeah, I second that.
    On my list of hacks is a 12V microwave, using 18 CCFL inverters in parallel.
    Ought to work, the magnetron only needs -5.6KV at something like 300mA so as long as they are kept cool with my own tested circuit to sum the outputs it works fine.
    Disclaimer:- Lots of dangerous voltage, Darwin Award factor 8. Advise extreme caution.

  12. Also worth mentioning, the reason why MWs have one power setting is due to the threshold on the magnetron. It needs 250mA to do anything, and 350 will cook it in short order.
    I did have a thought about PWMing the HV with a low side switch for my HTSC experiments, unfortunately this needs a part which is no longer available.

    • Chris C. says:

      For the simplest control scheme, this is true. But for a magnetron to work, the cathode merely needs to be near the right temperature. This can be achieved by maintaining a separately controlled current through the filament.

      Once set up this way and preheated, a magnetron can be started/stopped instantly, run at any continuous power level from zero to max, or even modulated with signals like audio. Of course, the more power it emits, the more it contributes to cathode heating; so the filament current should be reduced correspondingly based on a short-term average if you’ll be using more than a fraction of its power.

      Not sure if they’re still around, but there were microwave ovens with truly adjustable power, rather than the distinct on/off phases. They were more expensive, and I think also more prone to failure due to the more complex circuitry.

      • Eatith Mee says:

        Hard to pull off without a power sensor or some sort. I guess you could monitor Ik and If and use those values, and calibrate if not guess. but still… Controlling magy’s in this kind of application is tough and probably not worth the expense. I would also imagine that the magy and the cooking enclosure are matched to a certain power ratio and screwing with just the magy with no control of the box you’re radiating into could create VSWR issues and fry the magnitron too…

  13. Chris C. says:

    One other feature I recall from a past microwave, that may be of interest. An “auto cook” button that simply heated the contents until sufficient steam was detected by a humidity sensor. Worked well for tea, and somewhat acceptably for popcorn.

  14. 0c says:

    “Wife Acceptance Factor” — because the wife can’t possibly be an engineer too? Sexist garbage.

    • GenesisOfMoY says:

      If a wife were an engineer, their specialized training would make them acutely aware of the different needs and abilities of males and females, and their place.

      Sexism is defined as ‘prejudice’ and ‘discrimination’. Prejudice is defined as ‘making a decision before becoming aware of the relevant facts of a case’. (Discrimination is essentially ‘acting on prejudice’) If the differences are clear (to an engineer), then a true Sexist is one who treats the sexes as equal (in any sense of the word).

      One should embace their distinctive differences and abilities.

      • Luke says:

        You’re approaching this issue as if men and women are two radically different species, which is demonstrably not true at all. There are biological differences, sure enough, but there are vastly more similarities than differences.

        Making, say, a ballistic vest that conforms to female curves for the sake of increased comfort and protection, that’s perfectly valid and reasonable. Talking of a “wife acceptance factor” as if women can’t appreciate works of engineering, that’s abjact sexist.

        Ergo, you’re a sexist prick.

  15. Cyril says:

    Ok, but does it accept cookies ?

  16. Bogdan says:

    Why is it not called a picrowave?

  17. asd says:

    …does it sends messages to the future?!?
    (Steins;gate reference)

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