
Microcontrollers Not Allowed – Trolling a college instructor - tekacs
http://ultrakeet.com.au/write-ups/microcontrollers-not-allowed
======
jacquesm
In the age of 4.5 V 'flat' batteries we did something similar, put an AC
generator and another battery inside. (simple sine wave oscillator coupled to
a cheap small transformer salvaged from a transistor radio). Watch the local
electronics wizz tear their hair out in bafflement how an empty battery
(according to the DC volt meter) can power a lamp. Why resort to 4 letter
words if you can mess with the laws of physics directly?

~~~
sgt
I'd love to an electronics related prank in 2015. Just before I went on
christmas holiday, I inserted a snippet of JavaScript into our web-based IDE
(used by our developers) that flipped images upside down for a few seconds now
and then. Their first reactions - this must be a browser issue. Another
suspected an issue with the latest OS update.

~~~
sliverstorm
I never found those quite as fun.

    
    
        "Something is misbehaving, this is annoying!"
    

vs.

    
    
        "This is literally impossible. How is this happening!?"

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ChuckMcM
Generally if you can pull that off you are way past the course material :-) I
had a FORTRAN problem which asked to print the current bowling score given a
series of numbers between 0 and 10 (number of pins knocked down) and I had it
print out spares as '/' and strikes as 'X' and it didn't print the actual
score until you didn't get a strike (as is the custom on bowling.) and the TA
complained. (the assignment was to print out the score every frame) but the
professor was cool about it and had a nice chuckle so I did get full marks.

It is generally a sign of how good the faculty are at an institution based on
how they respond to this sort of exceptionalism.

~~~
roberte3
In college, I had to take a 1-credit hour lab course on MS-Office so that I
could take an accounting class I wanted.

The first lab featured a typing test app where you had to be able to type
40wpm or they made you drop the class. The app was a DOS app that a) made you
type a certain bit of unchanging text every time for the test, and if you
finished it type it again until you made a certain number of mistakes.

I wrote a borland basic TSR that pretended to be a keyboard, and typed in the
corpus repeatedly.

The instructor apologized repeatedly for making me take the class, and looked
utterly terrified of me for the rest of the semester after receiving my
300,000wpm test result.

~~~
jacquesm
You got off lightly there, the instructor could have made you his assistant
and farm out typing up all the course notes. At that speed that shouldn't have
taken more than a few minutes of your time ;)

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userbinator
Too bad the font isn't exactly the same as the real part (look at the 6, 7,
and 9 near the end of the video), or maybe that was intentional...

One thing that still amazes people today is just how _tiny_ a component can
be, and yet provide so much functionality. I've been working with electronics
for many years and the feeling still doesn't go away. The die of that
microcontroller is even smaller than the package, and if he had access to the
right equipment he could encapsulate one and make it basically identical to
anyone who didn't look inside:
[http://www.bunniestudios.com/blog/?p=208](http://www.bunniestudios.com/blog/?p=208)

On a more serious note, this brings up thoughts of surveillance implants and
backdoors: He could've made that "simulated" display driver record data into
the EEPROM of the MCU, and play it back at a later time. An external EEPROM,
if the internal one isn't big enough, isn't much bigger; you can get a 256KB
EEPROM in a 2x1mm package.

~~~
DanBC
The various devices that sit between a computer and a USB keyboard to record
the keystrokes are huge compared to how small they could be.

[http://www.keyghost.com/photos.htm](http://www.keyghost.com/photos.htm)

A well funded TLA could make these really hard to find.

~~~
makomk
If I recall the NSA leaks correctly, they already have.

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shabble
Reminds me of the excellent EE-trolling magic circuits by Henryk
Gasperowicz[1].

The number of things you could bury a little QFN MCU or similar in to play
silly buggers with people is huge, especially if you have the luxury of them
providing the 'support components'.

[1]
[https://www.youtube.com/user/Fredzislaw100](https://www.youtube.com/user/Fredzislaw100)

~~~
letstryagain
I really want to know how he did this one

[https://www.youtube.com/watch?v=PC55DPXSpr4](https://www.youtube.com/watch?v=PC55DPXSpr4)

I've been watching this video about once a month since 2013 and I still have
no idea what's going on!

~~~
jacquesm
Looks deceive, those are no ordinary LEDs and that's not an ordinary switch. I
have a good idea of how this was done but I may be off on the details. The
switch contains a coil which is shorted using the switch itself which allows
you to detect its presence or absence. That can be used to switch power to an
RF oscillator which is connected to another coil, setting up a field over the
green paper, relatively close to it. The LEDs contain a flip-flop + some
rectification and a cap, each LED can be triggered 'on' or 'off' by completing
the circuit between the legs (which otherwise function as antennae, that's why
they are bent the way they are, that way they function as a dipole).

It's a really neat hack, the guy must have amazing skills if he really has
that much hardware tucked away inside the guts of an LED, you'd basically have
to hollow out the whole thing, then put an SMD LED at the tip of the housing
and use the remainder of the space for the circuitry.

Time will tell how much of this was right if and when he reveals how this
trick was done.

~~~
usbreply
I'm on the phone so I won't google, but this is a very old story and if you go
to the guy's website, he has a writeup of exactly how he did it. (and yes, the
LEDs are hacked, they contain another hidden component)

~~~
jacquesm
Some googling later:

[https://plus.google.com/+HenrykGasperowicz/posts/dpwCPFDb3XM...](https://plus.google.com/+HenrykGasperowicz/posts/dpwCPFDb3XM?pid=5951325038093105842&oid=116398424278304767741)

[https://plus.google.com/+HenrykGasperowicz/posts/dpwCPFDb3XM...](https://plus.google.com/+HenrykGasperowicz/posts/dpwCPFDb3XM?pid=5933081763604822450&oid=116398424278304767741)

[https://plus.google.com/photos/+HenrykGasperowicz/albums/585...](https://plus.google.com/photos/+HenrykGasperowicz/albums/5852890237488086849/5945699199587972370?pid=5945699199587972370&oid=116398424278304767741)

So, indeed. Off on the details though, he's managed to sandwich the whole RF
generator into that switch package. Mad props and soldering skills way beyond
anything I could ever do.

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dripton
Beautiful. If I were teaching the class, you'd get the A and I'd remember when
it was time to write recommendations. But I remember some professors who might
have failed a student for pulling something like that. Or even accused him of
cheating, for "sneaking in an unapproved piece of rogue equipment." You need
to pick your spots.

~~~
bborud
Identifying professors that would fail someone for this is actually worth a
failing grade.

(Though at the age when you are most likely to be a student at a university it
probably would seem better to conform and get a good grade)

~~~
obstinate
What aspect of identifying them would make it worth it? I can see some
potential fringe benefits -- don't take future classes from that prof, etc.
But it's hard to imagine that those fringe benefits would actually be worth
the drop in GPA, which does matter.

~~~
MichaelGG
What does GPA matter for? Except special circumstances, like scholarships or
visas tied to GPA? I stopped 7th grade and truly dropped out at 10th, so I'm
biased. I've just never heard of GPA actually mattering.

~~~
GFK_of_xmaspast
[http://en.wikipedia.org/wiki/Dunning–Kruger_effect](http://en.wikipedia.org/wiki/Dunning–Kruger_effect)

~~~
rasz_pl
Michael Dell, Bill Gates

~~~
GFK_of_xmaspast
There's a big difference between being a college drop-out and being a high
school drop-out.

~~~
fubarred
The latter realized the futility of it sooner than the former.

~~~
MichaelGG
Eh, a compsci degree would have helped me in some cases. I ended up studying
algorithms and such by myself anyways. OTOH, I've interviewed people with
degrees in cs and they couldn't even explain binary search, let alone
implement it.

I dropped out cause my teachers were atrocious. My algebra teacher couldn't
explain why absolute value was a function, just that it was and we must learn
it, period. Another teacher said "computers just use binary". When I pointed
out I often saw hex, instead of pointing out why base 16 is a good fit for
writing binary numbers, she just stammered that computers were just binary.
Still my fault for giving up, but I had enough reason at the time.

~~~
mungoman2
Could you expand about absolute value? Is seems reasonable to me to think of
it as a function.

~~~
MichaelGG
Well it was introduced as "absolute value uses lines on each side. It means
you drop the negative if there is one". I asked what the point of it was,
cause it sounded sorta useless. Instead of saying "OK, well, how would you
express distance, x1-x2?", she was just stuck.

I suppose that's what happens when you have general teachers that don't really
know maths or science, don't really feel that it's interesting and offers
amazing ways to look at the world. In fact, I'd be surprised if she actually
knew beyond what she was teaching. It's not like middle grade teachers have to
take advanced courses, and they do have a wide workload.

------
pavel_lishin
> _If you attempt this project, your classmates will think you 're a nerd.
> You'll likely wind up getting your head flushed and/or balls greased._

I'm familiar with the concept of getting a swirlie (head flushed), but what in
the world is getting your balls greased?

~~~
farkanoid
Usually done to junior apprentice mechanics in Australia that wear shorts to
work (pants are always required in the workshop)

They're held down while someone else grabs a wad of black, filthy engine
grease. Then they shove said grease up the guys shorts and onto his balls

...It's really hard to get off, man

~~~
pavel_lishin
That does sound rather unpleasant :/

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na85
And now we've learned how an adversary might go about hiding an implant in a
personal computer. With more sophisticated fab techniques this would be
undetectable.

------
VLM
Fun anecdote... the 7447 is a BCD to 7seg decoder not a binary/hex to 7seg, so
no A thru F output when A thru F are input.

There are super expensive options like TIL311 and weird unobtanium that no on
has ever heard of.

But you can use a PIC in a tight loop checking the 4 inputs, lookup a byte in
a 16 byte table, and squirt out 7 bits of LED that display nice A thru F along
with the digits.

It'll be enormously slower than TTL so you can't build latches that way but
works fine for a nice slow asynchronous UI like a LED decoder / driver.

This has been redone a zillion times online. Its a good "first microcontroller
project".

There is at least one ancient 12 or 16 series PIC thats pin compatible with a
7447 with the proper programming although its been 20 years.

------
kileywm
A general comment on how-to instructions:

I really respect and appreciate that this article addressed pitfalls where
mistakes are common and disastrous. The step involving a router to clear a
cavity: lots of mistakes were made, because _it 's hard_ to do that step. It
takes courage to for an instructor to admit mistakes, and the pupil learns all
the better from those admissions.

For all of the Instructable, Pinterest, and various other how-to articles on
the internet, I believe we could all benefit from instructors being more
forthcoming about pitfalls like the author(s) of this article.

------
sepetoner
Relatively new EE here with a quick question. You can, technically, make a
system with the same output (spelling penis, etc.), without a microcontroller,
correct? With the proper frequency dividers, timers, and logic gates? Or am I
wrong here?

~~~
kelvin0
Of course, but then the instructor would have noticed the extra hardware and
it would have ruined the fun ...

~~~
TheLoneWolfling
Expert mode:

Make the discrete-component circuit to do this inside the logic gate.

(Especially hard as there are components that physically cannot be made small
enough (large caps / inductors, etc))

~~~
wiml
Intermediate mode: You could program the discrete logic onto a tiny CPLD and
probably still hide it inside the 74'193\. That way you'd still technically be
complying with the "no microcontrollers" constraint.

~~~
makomk
Sadly, it's probably a little hard to fit a CPLD in that kind of space without
wire-bonding equipment. They also tend to lack the infernal clocks that most
microcontrollers have these days.

------
gaberowe
You probably could have done the project for real in less time than routing
out the chip and soldering in the other chip but this is pretty sweet... For
all of my EE projects I always did the extra stuff and as a result learned a
ton.. The concept that engineering professors have to have stretch goals is
really clever to motivate the overachievers.

~~~
derekp7
It looks to me like he did do the project for real -- the write up mentions
programming the PIC to emulate the other part. Based on that I would guess
that you could pull out the hacked chip, and replace it with the 74LS193 and
it would work as normal.

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WillyNourson
Ah remembers me of this "genius" chinese external hard drive scam :
[http://www.neowin.net/news/fake-chinese-500-gb-external-
driv...](http://www.neowin.net/news/fake-chinese-500-gb-external-drive-is-one-
clever-paperweight-literally)

------
atmosx
Is there any kit/book/whatever for starters (along with books) to learn this
stuff? What goes where, how micro controllers, circuits, etc. work?

~~~
v2vz
Something like [http://amzn.com/B00005K86O](http://amzn.com/B00005K86O) will
get you started and have a good manual with step by step instructions. They're
a lot of fun! (Edit: I know it shows a kid in the picture, but its good adult
fun too!)

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chris_wot
At about this point, I feel the urge to explain that basically Tony Abbott
(our sledging PM) has basically helped kill off TAFE, but that's ok because
his government wants to give students loans at high interest rates for private
colleges to give an inferior education.

This is the PM whose latest innovation is to setup a ministry for science. Or
rather, re setup a ministry for science because he formed the first Australian
Federal government in 50 years that had no science ministry.

Turns out, that's a bad idea. _headslap_

~~~
davidgerard
It's OK! He put a climate change denier in charge of it ...

~~~
chris_wot
Whoever downvoted David - that is EXACTLY what he did.

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davidgerard
OK, I lost it when I got to the image captioned "FUCK."

