A Blissful Microwave

[Tim] had a problem with his microwave. The buzzer was exceptionally annoying, and once his hot pockets or pizza rolls were done, the buzzer wouldn’t shut off. A two-kilohertz tone infected his soul. It was the only sound echoing in a Boschian nightmare of reheated frozen food.

Unlike an existential ennui, an annoying buzzer in a microwave is something anyone can fix. [Tim] just took a pair of pliers to the buzzer and ripped it off the PCB. This left him with another problem — how to tell when his food was done. This was solved by putting the Windows XP startup sound in his microwave.

With the buzzer out of the way, [Tim] took an Arduino nano and loaded it up with the Windows XP startup sound. There isn’t much Flash on the Arduino, but it could hold an 18kB sample, enough to play the startup sound at 8kHz. The sound itself is PCM audio and easily stuffed into a sketch.

The Arduino listens for the 2kHz tone generated by the microwave and sends the XP startup sound through a tiny class D amplifier. After mounting a speaker inside the microwave, [Tim] has a very vaporwavemicrowave.

[via Hackaday.io]

57 thoughts on “A Blissful Microwave

  1. From what I understand, this will repeat as often as the original buzzer will, through the entire minute unless the door is opened earlier (though only oe time instead of three in a row). Nevertheless, this is something I should be able to repeat in half an hour today!

    1. That would be almost as irritating as the original buzzer. I implemented it so it will only play it once.
      Yes, it was a quick and easy hack.
      I realized later on that the sound was too low, so I’d to switch out the 0.5W element to a 3W.

  2. Another solution is to use some specialized IC that is designed to play a melody, like the UM66
    http://www.circuitstoday.com/wp-content/uploads/2009/03/um66.pdf, or the BT8028 http://www.iksemi.com/pds/product/BT8028-xx_01.pdf
    These chips are the one used in cheap best wishes cards, but the version in TO92 case could be used to make these circuits. I remember there was a motherboard that in case of oveheat started to play a melody through a piezo speaker I suppose that was using ine of these chips.

  3. Those microwaves are a triumph of marketing over reason.
    For 99 % of the usage we need 2 parameters.

    1. how much power.
    2. how long.

    Why do we need second precision on a minutes scale cook when we have not weighed the sample, measured the moisture content etc. So why the digital entry, we only need a single rotary adjuster.
    And why do I need to enter the power in 2 or 3 digits? all we need is a single rotary adjuster.
    And why do I need to select between time and power before entering the variables on the same interface.

    Why not use 2 rotary adjusters. One for time, one for power. Done.
    Less human interaction required.

    And what do the absolute cheapest microwave ovens on the market have? 2 rotary adjusters. Perfect.

    What’s next? Bricks that connect to the internet? why? each with their own face book profile so they can connect with other bricks around the world? why?

    My brother’s toothbrush recently failed to work because it could no longer establish a blue tooth connection with the phones brushing app !?
    What on earth?

    1. I generally agree except I find defrost by weight functions useful. Say I’ve frozen one of those ready meals from the shops that isn’t meant to be frozen. It doesn’t have cooking instructions that work from frozen but it does have a weight on it. Run the defrost function, set the weight, then later cook from fresh. I could probably do that with power and time dials but it’d be guesswork.

      1. Two dials was standard in the past and while it was guesswork getting used to the thing, after one acquired experience, the results were no different than now with precision controls.

          1. Testing I’ve done indicates the different power settings just result in different proportions of time that the magnetron is powered on. 50% would be alternating on and off at some interval of a second or so.

    2. Sorry I have to disagree strongly with your assertions.

      I regularly, in fact multiple times a day heat things for as little as 8 seconds and yes 2 seconds does make a difference when heating small quantities to a very narrow temperature range.
      18 seconds is a good time in my microwave to heat 180mls of baby formula from 23 degC to a suitable drinking temperature.

      Hearing a jar of bay food takes 20seconds if the food is left in the jar but only 10 if it’s in a plastic food bowl.

      1. Same here. I usually use our microwave in sub 1 minute increments: 30 seconds to heat some milk for coffee. 10-15 seconds to heat up leftover cat food. And 6-7 seconds to soften a small piece of butter for our cat (don’t ask).

        Unfortunately, I didn’t do enough research when we got a new microwave after remodeling our kitchen. Our new model has “quick start” feature that cannot be turned off (that I know of). Basically, put food in, hit a digit on the keypad, and it starts cooking on high for that many minutes. To enter sub 1-minute times, I have to hit “time cook” first, then enter the time, then press start, adding a button press to the usual process.

        I often forget that and end up starting the microwave after hitting “1.” Granted, I can often just stand there and stop it after the requisite number of seconds have elapsed, but I’m often doing several things at once, so sitting there and watching the microwave for 15 seconds is annoying.

        1. There’s a microwave in the break room at work that is very similar to yours. Except it adds one extra step by making you enter a power level after already having to press “cook time” and then entering the time.

          1. The one I have has a rotary encoder and a lot of buttons, To enter power you have to use 1 button to start entering, turn the rotary encoder right to increase time and left to decrease time and it starts at one minute. Then press the same button to set the power level but turning right decreases the power level instead of increasing. If you press the button twice fast because you want to use max power anyway then it doesn’t respond. You need to wait at least a second between presses.

        2. I’ve found the Sharp Carousel series units to be the best user interface for me, because of the minimal button presses to do my most common jobs.
          Why punch in a time for one minute when this machine has it as a default. Simply put item in, hit Start, remove coffee / sandwich etc. whenever. Oven stops when door is opened at any time.
          If I want to do sub-minute times I always hit the same number twice in quick succession, to speed things up. ie. 11 seconds, 22 seconds, 33, 44.

          Zap for another minute or more, just press Start again. If already running, minute is incremented.
          Next the power level, when needed. Enter time then High-Med-Low, Start.
          Convection cooking? Time, required temp button in deg C, Start.
          Pre-heat? Temp button, Start.

          Other modes such as Convection/Micro mix, and food weighing is also easy. The door has a pull-down handle (food can be placed on the open door)in one operation, I dislike intensely the type where a door button has to pressed in (hitting your cuticles on the sharp corner) THEN quickly switch to catching the door as it flings open. Two distinct steps in the user interface just to get food out is too much.

          IMO the Sharp UI and operation is so well thought out I want to use it forever. I replaced the main cap about 6 years back, and I’ve bought a second hand identical oven off eBay as a spare.

      2. Who said the scale has to be linear? Look at an old measuring jug, it is tapered to the bottom, like a rain meter. This provides this good precision and good scale. unfortunately the marketing department has convinced the public that it looks old, so now I need 3 measuring jugs to provide me the precision I need at the bottom of the jug.

      1. $5,000
        Only heats foods approved by and sold by the Apple Food Store (patented concept of food store, we’ll sue all other food stores)
        Runs iOS and will degrade in performance with every forced upgrade, unable to boil water after the next iOS update.

        iWave 2+
        $6,000

      1. With digital controls on an over the range microwave, you end up with a keypad that starts acting all wonky should steam ever get near it. It only works correctly after a few days of drying out.

    3. “What’s next? Bricks that connect to the internet? why? each with their own face book profile so they can connect with other bricks around the world? why?”
      They will flood the 2.4ghz band and overtake wifi totally, mW2.4 was born. The first system message read “hee, whats cooking” before it sparkled into fire, blew up and almost killed 99% of the single population on the world.

    4. I have used two microwave ovens with digital entry, both have a knob that increments the time in 10 or 15 seconds chunks and the power is preset on some levels, one has a digital control, the other has nother rotary knob. If you have a combi microwave of course the selecion could be more.

    5. We usually bring up the microwave oven as a bad example when we are discussing bad interfaces at my local hackerspace. Quite often some one will bring up the simplicity of mechanical microwave oven.
      But mechanical timers lacks the resolution that the digital have.
      It’s almost impossible to get a short 10s run on a mechanical timer, and the timer tends to have a error of 30s.
      I don’t mind the extra functions that an electronic interface brings, as long I have two big dials for power and time.

  4. Oh I think if my microwave played the Microsoft start up sound every time it stoped I’d thow it out the window – it would be much more satisfying if I was on the 23rd floor of a high rise rather than a single level home – but it’s the thought that counts :)

    But that all aside it’s a neat solution to the problem

  5. I had the idea to use a Raspberry Pi to control my microwave’s time and power. Use my barcode scanner to shoot an item’s UPC on the packaging, refer to a custom database to get the time and power. But then I remembered how lazy I am and figured being lazier was more work than worth on this one.

    1. Turn your power down.

      As the burrito (or a bunch of other foods) melts, it absorbs microwaves better. The only thing to stop the resulting localized runaway heating is conduction of heat to the still-frozen parts, and there’s nothing you can do to speed that up, so you’ve gotta slow the heating to match.

  6. I used tape.
    A tiny piece over the buzzer dropped the frequency and volume just enough to not annoy me.

    Honestly, I hoped the buzzer would just die, but eight years later it’s still

  7. Today I’ve converted my windows XP machine, when it’s ready booting it will play a very pleasant microwave oven BEEP-BEEP-BEEP sound. This is so practical… now I can hear my PC from all around the house, I never could hear my PC so I never knew when it was ready for use.

    But seriously, I think the guy has made a cool adjustment to his microwave. Fun project! I guess he has a laugh every time one of his guests hear this for the first time.

  8. I would rather have the Brian Eno track that the original Windows had. Or the Robert Johnson ditty ’bout Hot Tamales.
    Scan bar code and search song database for appropriate song for food item.

      1. Rice, rice baby
        Rice, rice baby
        Alright stop, grab a table and a menu
        Ice is back in this Oriental venue
        Hungry, for a little Chop Sui
        I want Chinese, not Hong Kong fui
        You know what you want
        Yo, cant decide
        Column A, Column B
        …..

  9. On some microwave ovens you can disable the alarm beep and/or the keypad beeps, though the directions aren’t alway in the manual. Seems to be a feature that is becoming rare; my new one doesn’t have the option.

  10. How about a Bluetooth add on, so it could send a message to your smart phone? Choose any “ringtone” you like.

    Better yet, a WiFi IOT hook up. Not only could it send a “done” message ringtone to your phone, but could also live stream the cooking process from a strategically placed camera in the oven’s interior.

    Bonus Feature: once you have that camera, you might as well mount a scrap 12″ LCD display on the front of the oven door, so you can stream a video of what’s cooking inside.

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