cRPG

Off Topic => General Off Topic => Topic started by: Molly on January 13, 2014, 03:26:28 pm

Title: Woohooo - I am so good!
Post by: Molly on January 13, 2014, 03:26:28 pm
My boss... she wanted a pulse of 15V at 125kHz with 10% on-time, switched by the microcontroller.

On Thursday I made the schematic, today I slapped the stuff together and...

...that stuff works right from the start like a charm!

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I'm so proud of myself that I had to share my success even if nobody gives a shit :D

Those beautiful slopes, so steep and so quick, so awesome! They are actually so beautiful that I am pretty confident that it can go even faster :D
Title: Re: Woohooo - I am so good!
Post by: Umbra on January 13, 2014, 03:30:39 pm
How expensive is that equipment, i remember my friend frying one in highschool
Title: Re: Woohooo - I am so good!
Post by: Nightmare798 on January 13, 2014, 03:56:10 pm
My boss... she wanted a pulse of 15V at 125kHz with 10% on-time, switched by the microcontroller.

On Thursday I made the schematic, today I slapped the stuff together and...

...that stuff works right from the start like a charm!


I'm so proud of myself that I had to share my success even if nobody gives a shit :D

Those beautiful slopes, so steep and so quick, so awesome! They are actually so beautiful that I am pretty confident that it can go even faster :D

I studied something like that on high school, but I dropped out because our teacher on engineering practice was a moron.

We like seriously had to work with 20+ years old equipment.
Title: Re: Woohooo - I am so good!
Post by: Latvian on January 13, 2014, 04:07:55 pm
and what is that, explain to people like me ( dum dums).
Title: Re: Woohooo - I am so good!
Post by: Molly on January 13, 2014, 04:29:08 pm
How expensive is that equipment, i remember my friend frying one in highschool
Those analog ones aren't that costly anymore... dunno, maybe a few hundred euros. We have a few digital ones that were around 20.000€ a piece, like a year ago. And that's already with percentage off cuz University and stuff. The old and cheap ones are good enough for the stuff I do atm.

and what is that, explain to people like me ( dum dums).
Well, basicly it's a simple voltage pulse of 15V. But it's like really short which is one of the tricky parts... as you can see it's around 700 nano seconds long (700*10^-9 seconds/that's way less than a blink of an eye). It's just for testing a certain sensor setup.
I am using my microcontroller, which supplies me with 3,3V, to switch my circuit I built which then provides me with the 15V pulse I need.

Basicly, I built a really fast switch :) The spectacular part is actually the really sharp edge and that there is no oscillation after turning it on and off again. The overall sharpness of the pulse is just beautiful. I am just excited cuz I didn't expect that my quick'n dirty solution would work that nice.
On Thursday I am planning to half the time of the pulse. Hopefully down to something around 400ns.

Mathematically it's sweet when you just take a look at the edge. Let's assume that the raise of the voltage happens in something like 35ns, which is probably still too long compared to the real pulse, that means the voltage makes a jump from 0V to 15V in that time window:

That already equals 0,395V per ns. Soooo sweet... :D If I can half the pulse time, I doubled the Voltage per ns! Probably doesn't sound that spectacular but it actually is, considering I build all that with parts that sum up to 25cents or something :wink:

Title: Re: Woohooo - I am so good!
Post by: Fredom on January 13, 2014, 05:07:14 pm
I am working with Microcontrollers in school too atm, hard stuff... Good work Molly! :mrgreen:
Title: Re: Woohooo - I am so good!
Post by: NuberT on January 13, 2014, 05:14:58 pm
I studied something like that on high school, but I dropped out because our teacher on engineering practice was a moron.

We like seriously had to work with 20+ years old equipment.

Are you certain, that he was the moron? :rolleyes:
Title: Re: Woohooo - I am so good!
Post by: Armpit_Sweat on January 13, 2014, 05:29:51 pm


My boss... she wanted a pulse of 15V at 125kHz with 10% on-time, switched by the microcontroller.

On Thursday I made the schematic, today I slapped the stuff together and...

...that stuff works right from the start like a charm!

I'm so proud of myself that I had to share my success even if nobody gives a shit :D

Those beautiful slopes, so steep and so quick, so awesome! They are actually so beautiful that I am pretty confident that it can go even faster :D

:(

That's me after reading your post two times, and looking at the pictures for few good minutes:

(click to show/hide)

But that's seriously cool stuff! I really envy you right now :)
Title: Re: Woohooo - I am so good!
Post by: Molly on January 13, 2014, 07:52:15 pm
Yea, I get that someone who isn't involved into electronics  probably won't go all excited about that :D


My life is sooo sad and boring :cry:
Title: Re: Woohooo - I am so good!
Post by: Logen on January 13, 2014, 08:01:03 pm
are you a wizerd or something
Title: Re: Woohooo - I am so good!
Post by: Clockworkkiller on January 13, 2014, 08:04:35 pm
This thread makes me feel stupid
Title: Re: Woohooo - I am so good!
Post by: Tovi on January 13, 2014, 08:08:47 pm
Today I had a good fuck with my wife  :mrgreen:
Title: Re: Woohooo - I am so good!
Post by: Latvian on January 13, 2014, 08:13:55 pm
Today I had a good fuck with my wife  :mrgreen:
do did I :D   visitors can't see pics , please register or login
Title: Re: Woohooo - I am so good!
Post by: Kafein on January 13, 2014, 08:33:03 pm
That looks like a Fourier Transform, still not fast enough.
Title: Re: Woohooo - I am so good!
Post by: Miwiw on January 13, 2014, 09:44:22 pm
You're a true master, Molly!

I had 2 courses about Electrical Engineering. Already too difficult for me, doing practical stuff, even tho it's probably the easiest things we did you can do in that area. Luckily I won't need it anymore in the future. :)

@ nightmare:

Sooo... why should 20+ years old stuff not work to teach you basics of it? Why's the teacher a moron then?
Title: Re: Woohooo - I am so good!
Post by: Smithy on January 13, 2014, 10:06:44 pm
My life is sooo sad and boring :cry:

It's not sad a boring if that's what you're passionate about.  I could rant about similar things all day.. You're not alone.  :)
Title: Re: Woohooo - I am so good!
Post by: Kafein on January 13, 2014, 11:11:18 pm
Also why are there points all over the place at the first two transitions
Title: Re: Woohooo - I am so good!
Post by: Nightmare798 on January 13, 2014, 11:18:47 pm
Are you certain, that he was the moron? :rolleyes:

What would you think of a teacher that wont even give you the list of stuff that you have to learn for a resit?

Yeah he was a moron. A collosal one.


@ nightmare:

Sooo... why should 20+ years old stuff not work to teach you basics of it? Why's the teacher a moron then?

Let me give you an example. Our school got a new type of light, precision solders, perfect for usage with small electronics we worked with. what did he do? He instead had us use the heavy old outdated pieces of shit which required frequent replacing of the soldering wires, which made us waste our precious time to finish our work. Half of the time, I couldnt finish the job because it malfunctioned every 30 minutes. Not to mention the fact that the soldering was usually half assed due to the weight of the solder.

When I asked why arent we using the new ones he responded that he wants us learn on the old ones.

So there I sit, twisting my arm like bundle of sticks with 1.5kg weighting soldering pistol, while the new light ones which would make the work a breeze were lying uselessly on the shelf.

The funniest part? The government gives them funds so they can purchase and let us use new updated equipment that makes our work easier.
Title: Re: Woohooo - I am so good!
Post by: zagibu on January 13, 2014, 11:19:46 pm
I would think that the points are delimiter lines you can adjust to measure the visible length of a signal. Kind of like a ruler.

My boss... she

Also, fail in three words.
Title: Re: Woohooo - I am so good!
Post by: Molly on January 14, 2014, 12:36:20 am
Those doted lines are just rulers for measurements. It ain't that precise but it gives a rough idea. That's already the deluxe version when it comes to the older oscilloscopes :D

And it has nothing to do with Fourier, it is just a voltage pulse. Nothing special really,  except for the frequency and the steepness.

Consists of 3 transistors and 4 resistors. Nothing else. It's kinda old school and elegant :) Hard to appreciate when you're not into the subject, I guess.
Yes, there is actually a certain elegance to a nice equation, to a nice pcb, an nice circuitry... Probably very hard to appreciate for"normal" folks though, I understand that.

It just feels good to get an elegant solution to a non-trivial challenge (never problems, there are only challenges :D) with a few cheap standard parts.

I am surprised how many people actually came into contact with electronics in a proper and not just by PC gaming or touching the smartphone :P
I always thought that it's rare. I'm curious what you guys actually did in those school lectures about electronics. How deep did it go? Did you go past the flashing LED?
Fredom said something about programming a microcontroller... which one? And which language are you using? Which kind of programs did you run? How much actual background is taught on programming itself? How much details are done on the hardware of a microcontroller? VHDL? Assembler?

If someone is actually answering those questions, it would be nice to know the nationality and how long it's ago... :)
Title: Re: Woohooo - I am so good!
Post by: Lt_Anders on January 14, 2014, 02:45:03 am
The closest I came to anything electronic related was when I paired up with a EE major kid and we built a robot to shoot a ball for a compatition. Everyone else used a potato gun type thing and beat our record, but we got all da style points.

But yea, Being a Structural Engineer, I don't give 2 shits about some small ass circuit boards. I'm more worried about the fucking column breaking cause some asshole contractor fucked up the installation and now we gotta do shit to fix it cause they fucked up.(happens so often it's not funny, like, contractors suck. Some been doing it so long they got that "this is how it's done!" mentality even if it's completely wrong in some instances)

So, congrats on your test. I assume you're a TA or research assistant of some kind?

Should scan some of the stuff I got and post it so you can see the crap I've corrected that contractor's have messed up. Mostly houses so it's not like it's super scary, but they muck it up often enough. Sometimes, they don't even wait  for us to get our plans to them and build it BEFORE we even got plans up and then we gotta give them drawings so that inspectors are happy with it.
Title: Re: Woohooo - I am so good!
Post by: Molly on January 14, 2014, 09:48:33 am
I lack the proper English term but I guess my brother was a Structural Engineer too.
He worked for a small but international recognized firm which build climate chambers... but those big ones.
I know he was responsible for several chambers for Audi, VW and BMW where they test their prototypes and new cars in. One chamber with a temp range of -65°C up to 110°C. Pretty impressive stuff with all the statics, considering the extreme temperatures which work with the whole structure.
Before he studied, he became a skilled labor for climate isolation. So he knew all the isolation stuff and had the studies about constructional engineering on top of that...

He was less annoyed by contractors but he cursed every single architect he had to work with. He always complained that they made plans for some sky palace which wouldn't stand for more than 1 hour stable if it had been built like they wanted it :D

Anyway, back to topic :P

I actually have a few screenshots I could post about what my real challenge to design is atm. That pulse was just something to get more time for the real thing. Though I won't do it if nobody actually cares about it cuz it would mean a bunch of explaining :wink:

But keep those stories about your electronics experience coming... it's interesting to read.
Title: Re: Woohooo - I am so good!
Post by: IR_Kuoin on January 14, 2014, 09:55:42 am
Gj, even though I have no idea what that means, at least it works, hue.
Title: Re: Woohooo - I am so good!
Post by: Vibe on January 14, 2014, 09:57:22 am
It looks like your patient is dying, doctor.
Title: Re: Woohooo - I am so good!
Post by: Molly on January 14, 2014, 10:01:16 am
That looks like a Fourier Transform, still not fast enough.
Reminded me of this masterpiece:
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Title: Re: Woohooo - I am so good!
Post by: Lt_Anders on January 14, 2014, 10:21:18 pm
I lack the proper English term but I guess my brother was a Structural Engineer too.
He worked for a small but international recognized firm which build climate chambers... but those big ones.
I know he was responsible for several chambers for Audi, VW and BMW where they test their prototypes and new cars in. One chamber with a temp range of -65°C up to 110°C. Pretty impressive stuff with all the statics, considering the extreme temperatures which work with the whole structure.
Before he studied, he became a skilled labor for climate isolation. So he knew all the isolation stuff and had the studies about constructional engineering on top of that...

He was less annoyed by contractors but he cursed every single architect he had to work with. He always complained that they made plans for some sky palace which wouldn't stand for more than 1 hour stable if it had been built like they wanted it :D

Anyway, back to topic :P

I actually have a few screenshots I could post about what my real challenge to design is atm. That pulse was just something to get more time for the real thing. Though I won't do it if nobody actually cares about it cuz it would mean a bunch of explaining :wink:

But keep those stories about your electronics experience coming... it's interesting to read.

Oh I hate architects too. Like, can't you shits use standardized paper? why not 30X42 or 24X36, you just HAVE to use 27.5X43...wtf?....
In most cases, though, I do houses so we rarely get stuff that makes me want to punch the architect in the face. Usually it's just mild annoyance at shit they do. It usually ends up with the builder calling us up and going, "WTF is this shit?" to which we go "Architect."

I'm still in the training period for doing actual strucural engineering. It's not really an internship, but it's not really a job. I'm a "working" intern would be the best way to describe it. 40 hrs a weeks, standard pay scale(hourly), and I draw plans and limited engineering. Only been at this job for about 3.5 months.
Title: Re: Woohooo - I am so good!
Post by: no_rules_just_play on January 14, 2014, 11:19:29 pm
what exactly is your job called molly?
Title: Re: Woohooo - I am so good!
Post by: Clockworkkiller on January 14, 2014, 11:31:13 pm
I got tasered once, does that count?
Title: Re: Woohooo - I am so good!
Post by: zagibu on January 14, 2014, 11:48:07 pm
I got tasered once, does that count?

Well, don't wag with your tail in public, meowoofer.
Title: Re: Woohooo - I am so good!
Post by: Jona on January 15, 2014, 12:34:51 am
Those analog ones aren't that costly anymore... dunno, maybe a few hundred euros. We have a few digital ones that were around 20.000€ a piece, like a year ago. And that's already with percentage off cuz University and stuff. The old and cheap ones are good enough for the stuff I do atm.
Well, basicly it's a simple voltage pulse of 15V. But it's like really short which is one of the tricky parts... as you can see it's around 700 nano seconds long (700*10^-9 seconds/that's way less than a blink of an eye). It's just for testing a certain sensor setup.
I am using my microcontroller, which supplies me with 3,3V, to switch my circuit I built which then provides me with the 15V pulse I need.

Basicly, I built a really fast switch :) The spectacular part is actually the really sharp edge and that there is no oscillation after turning it on and off again. The overall sharpness of the pulse is just beautiful. I am just excited cuz I didn't expect that my quick'n dirty solution would work that nice.
On Thursday I am planning to half the time of the pulse. Hopefully down to something around 400ns.

Mathematically it's sweet when you just take a look at the edge. Let's assume that the raise of the voltage happens in something like 35ns, which is probably still too long compared to the real pulse, that means the voltage makes a jump from 0V to 15V in that time window:

That already equals 0,395V per ns. Soooo sweet... :D If I can half the pulse time, I doubled the Voltage per ns! Probably doesn't sound that spectacular but it actually is, considering I build all that with parts that sum up to 25cents or something :wink:

I took one electronics engineering course last year when I was planning on taking a EE minor. Wasn't really my thing. I understood the material well enough, and found it all very interesting, but the way everything was graded just really turned me off. More points for arriving at the right answer than was awarded for your work. Sure, makes sense, but the fact that on many questions no partial credit was awarded AT ALL, just really sucked. It's annoying how minor things like that turn you away from doing what you want. I didn't do so well in that course and if I continued following that road I would probably graduate with some shit GPA and get hired by no one. :(

Anyways, I have to say that my first reaction once I saw the time interval was "DAMN NICE SLOPES!" lol... very steep indeed, almost instantaneous. Nice job man.


Also, fail in three words.


Beat me to it.  :(
Title: Re: Woohooo - I am so good!
Post by: isatis on January 15, 2014, 01:47:01 am
That make me remember my last electric and magnetism course in my final practice exam!

But we had less amateurish material of course!

Because free education in Québec is like that of course!

:P
Title: Re: Woohooo - I am so good!
Post by: Molly on January 15, 2014, 09:51:42 am
Well, it's not like I couldn't use better equipment cuz there is none. Instead I use the old and cheap stuff cuz it fits my purpose.
Though I probably should switch the oscilloscope for a faster one. That 1µs/div is already the lowest it can display... :?

what exactly is your job called molly?
I'll be an Electronic Engineer specialized in Microelectronics and -systems. In theory I am able to design a chip, fabricate it in a clean room, make an ASIC out of it, design a circuit for the system using the ASIC, fabricate the PCB, test the circuitry. Personally, I specialize on circuit and PCB design, including testing and "quick'n dirty"-software design :) I'm the hardware dude basicly.
I am still studying on the "old" German diploma which is a bit higher set than a Master degree.


The actual application I am working on is this:

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We have an array of piezo-sensors on a plane-wing which is used to measure the structural integrity of the wing itself. It works roughly like this: you send out a pulse of a certain waveform through the wing which gets picked up by the sensors. Depending on the measurements the sensor did, you can relay information about the structural integrity of the wing. That's more or less the whole idea without going into the details.

That waveform in the picture is the test signal that has to be achieved. The big challenge is to get it fast enough. On the picture it runs with something around 10kHz (don't remember the exact frequency anymore) but what we actually want is something between 150kHz and 250kHz.
Creating the waveform on a microcontroller is rather trivial. All I had to do is to re-create the waveform with a math-program (I am using Mathlab for this) and then generate discrete values for it. Basicly, a huge row of numbers that follow the form of the function. I wrote myself a little script for it where I can specify how many cycles I want, how many discrete values it generates. Then I convert those into hexadecimal values, save them in a certain format and upload them as a lookup table to my microcontroller.
With that lookup table all set, I just call a for-function to put one value after the other on the DAC (digital-analog converter) of the µC.
That was done rather quickly, took me about a day to get the above output.

I realized that it wasn't even closely to the frequency I had to achieve tho. Although the µC (XMEGA256) is a really potent one and runs with 32MHz, it wasn't fast enough to handle the for-function and the digital-analog conversion at a speed anywhere near I would need it.

I played around with the discrete values, mainly using less cycles and less values overall which resulted in this:

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As you can see, compared to the first picture, it has very visible steps now but the frequency was barely raised.

I decided to change the circuit. Now I am not using the internal DAC (digital-analog converter) of the µC but an external ASIC instead. Well, in theory it should be way faster and I am confident it will be in the end but right now I am just getting bullshit values out of it.
The setup is now that I use 8 output pins of my µC on the ext. DAC as a bus. Everyone with a bit of an background in digital technology knows the order of the binary bits.
All I do now is to read the value from my look up table which comes next and put it onto my output register (1 Byte) which is connected to the ext DAC. Unfortunately the output of the DAC is complete garbage and I have no idea why :D

The bits seem to have the wrong analog values when the DAC generates the voltage. The DAC does a conversion but those values are all wrong and inconsistent...

That's where my actual challenge is right now. Creating that pulse was just a surprising "side quest" to appease the other institute involved in the whole project :D

The all dominating challenge is the frequency. It sounds rather unspectacular but it is actually everything but trivial. Speed is always a challenge in electronics :wink:


Who's not bored by now? :D
 
Title: Re: Woohooo - I am so good!
Post by: Tovi on January 15, 2014, 08:59:38 pm
I tried to fix my electric fryer but I failed.  :oops:
Title: Re: Woohooo - I am so good!
Post by: no_rules_just_play on January 15, 2014, 10:10:10 pm
I had to use mathlab last year when I did bio engineering, fuck that thing was a bitch :D