
A Linux-powered microwave oven - kirschner
https://lwn.net/Articles/674877/
======
tezza
For some reason you can't open the microwave door to get your food.

After searching LWN you find a comment at the bottom that you need to run
fuser on /mnt/microwave/0/door/mechlock and kill the
dbus_microwave_door_status daemon.

Search google again to discover a blog from 2004 detailing how you use dmesg
and modprobe to find out which number your microwave door is bound to.

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logicrook
Superb satire, it reminds me of "Why GNU/Linux Viruses are fairly uncommon".

~~~
ultramancool
[http://www.gnu.org/fun/jokes/evilmalware.html](http://www.gnu.org/fun/jokes/evilmalware.html)
for anyone who hasn't seen it yet.

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Sanddancer
Linux on a microwave feels a lot like the NetBSD toaster from all those years
ago. Additionally, it doesn't make sense from a technical perspective. People
have converted toaster ovens to do smd reflow with an arduino [1], and that
requires a lot more delicate control of temperature and timing; hell, Linux is
worse for the job because its realtime capabilities are so poor. Also, if
you're going to go through the trouble of redesigning the microwave, you'd do
a world of wonders to get rid of the magnetron altogether in exchange for a
few microwave heating transistors [2]. That way, you can target hot spots
better, have better power control, and generally make better food. If you're
gonna remake the microwave, do the job right.

[1] [http://whizoo.com/reflowoven](http://whizoo.com/reflowoven) [2]
[http://www.nxp.com/products/rf/rf-power-transistors/rf-
cooki...](http://www.nxp.com/products/rf/rf-power-transistors/rf-
cooking/2450-mhz-250-w-cw-32-v-rf-ldmos-transistor-for-consumer-and-
commercial-cooking:MHT1003N)

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jahnu
Can anyone here explain to me why microwave ovens always have their power
settings as multiples of some value, e.g. 200/400/800w but never have the
ability to set a specific power output, e.g. 425w.

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skykooler
Microwave ovens use magnetrons to produce the microwave radiation. Magnetrons
cannot be run at anything less than full power. Some microwaves have
additional coils in the magnetron that can be connected to increase the power
level, but it's limited to the power levels you can get from the various
combinations of coils. For the same reason, running a normal microwave at "50%
power" actually means it runs at full power for several seconds, then switches
off for several seconds, then repeats. The pulses are so long because starting
and stopping are hard on the magnetron.

~~~
bazzargh
Solid-state microwave generators have been developed to replace magnetrons
recently, and they can run at variable power.

[http://electronicdesign.com/blog/say-good-bye-last-vacuum-
tu...](http://electronicdesign.com/blog/say-good-bye-last-vacuum-tube-product)

 _Using the MHT1003N, manufacturers can use from one to eight of these 250 W
units to build a microwave oven with the desired power level. And the
magnetron’s 4 kV power supply goes away in place of a supply of 28 to 50
volts. Furthermore, the crude on-off control of the magnetron can be replaced
with full variable power control._

However, as far as I know there's no consumer devices containing things like
this yet - the only ones I've seen were concept devices from Freescale. This
article suggests we won't see them until 2017, and then only in high-end
cookers:

[http://www.electronicsweekly.com/news/design/the-future-
of-m...](http://www.electronicsweekly.com/news/design/the-future-of-microwave-
cooking-is-solid-state-2016-01/)

~~~
aidenn0
They are as-yet too expensive for low-end microwaves, IIRC they are around
0.10 per watt in quantity so $100 in parts just for a 1kW oven.

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noonespecial
That's a fine looking death machine there. Then again, the buttons on my
microwave are also so horrible I've been tempted...

If he gets the voice control worked out to where I can say "Tea, Earl Grey,
Hot" I might be sold.

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chipperyman573
>Then again, the buttons on my microwave are also so horrible

Is it really _that_ hard to push "Time cook -> 2 -> 3 -> 0 -> Start"? I mean
_come on_ I can understand wanting to optimize your life or whatever but
complaining about microwave buttons seems a bit ridiculous.

~~~
ggoss
For the record, many of the microwaves I've used have required something more
like "Time cook -> 2 -> 2 -> 2 -> 3 -> 0 -> 0 -> 0 -> Start -> Facepalm" than
the intended "Time cook -> 2 -> 3 -> 0 -> Start".

TL;DR: pressing buttons is easy, but sometimes they press your buttons back.

~~~
profmonocle
Ahh memories. Back in college I had a microwave where almost all of the
buttons stopped working over time. Eventually I had to set everything for
something like 4:44 or 44:44 and use the timer on my phone to know when to
take it out.

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BuildTheRobots
Hmm... as a microwave oven is (essentially) just a large 2.4ghz transmitter,
does this mean I'll have to stop running linux on it if the FCC gets their way
and locks down radio modifications?

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gravypod
This reminds me a lot of this project:
[https://www.youtube.com/watch?v=e2YtARzJTys](https://www.youtube.com/watch?v=e2YtARzJTys)

It integrated a raspberry pi with a barcode scanner and microwave. All you
needed to do to cook prepackaged food was scan the barcode. It had all the
times set in and all of the mixing and instructions.

I think that feature is useful.

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pkaye
Once I tried to warm up some food in a microwave oven at work and it would not
run (no light or fan.) I opened the door and now the fan was running. Close
the door and it stopped again. No idea if there was any microwave radiation
coming out but I quickly unplugged that thing and put a note on it for
facility staff. Not sure how a safety sensor would fail in that manner!

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aidenn0
My microwave has a horrid interface; instead of buttons for setting the time
to cook, it has a digital dial with a bizare nonlinear sensitivity.
Fortunately it has a "add 30s" button, as the digital dial is so hard to use
that I press the "add 30s" button 10 times for something that needs 5 minutes
to cook.

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tlarkworthy
related $1500 June machine learning vision oven thingy
[http://fortune.com/2015/06/09/june-smart-
oven/](http://fortune.com/2015/06/09/june-smart-oven/)

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MaddoScientisto
Can I link my phone to it? Can I use it to generate micro black holes and send
messages to the past?

This is important

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na85
Please no novelty accounts. This isn't Reddit.

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MaddoScientisto
oh come on this is my regular nickname, I just made a funny post, that's all

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andrewclunn
This was really just done so that Richard Stallman could eat popcorn again
without going into a rant. Nobody tell him that the genes for the corn it's
made from are likely proprietary.

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testerooooooo
He should only eat GPL'ed popcorns.

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kuschku
Actually, there are universities doing genetic research on corn that have
published some variants under free licenses.

So he might actually be able to eat corn under GPL license.

~~~
testerooooooo
Like I was joking or something...

