Don't have oscilloscope? Now you do, and free!!

Thread Starter

count_volta

Joined Feb 4, 2009
435
A couple of days ago I needed to use the oscilloscope to observe the behavior of the digital circuit I was designing for university. I was too tired to drive all the way to school to use their scope. So as always laziness is the mother of invention. I looked online and found this.

http://www.zeitnitz.de/Christian/scope_en

Its totally awesome, and all you need is a sound card to use it. You just connect your input into the microphone jack. It works exactly like a real oscilloscope and what amazes me is how accurate it is!!!

I later went to school and compared what the real oscilloscope gave me. Very close actually!!! And btw it has a built in spectrum analyzer!!!

Be careful, anything higher than 1V input and you will fry your sound card, I guarantee it.
 
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Thread Starter

count_volta

Joined Feb 4, 2009
435
Thanks, good links. Will look into them.

Even if my oscope isn't entirely free, its so good I would even pay for it. It saved my ass.

When I built my circuit the first time it didn't work correctly, imagine if I had no scope. I would bring the circuit to school thinking that it works. That would not be good. Instead I fixed it and saw with the scope that it finally works.
 

SgtWookie

Joined Jul 17, 2007
22,230
Be aware that you can inadvertently destroy your sound card (and even your motherboard) if you are not careful with these types of things.
 

Thread Starter

count_volta

Joined Feb 4, 2009
435
Actually this scope is free unless you want it for commercial use, which is true for most things.

  • The use of the software and of the documentation is granted free of charge for private and non-commercial use in educational institutions
  • Any commercial application requires a corresponding license (see below)
  • Distribution and sale of the program is prohibited. Contact the author in order to obtain a resale license
 

steveb

Joined Jul 3, 2008
2,436
It works exactly like a real oscilloscope and what amazes me is how accurate it is!!!

I later went to school and compared what the real oscilloscope gave me. Very close actually!!! And btw it has a built in spectrum analyzer!!!

This is very cool, for sure!

It's important to point out to people that this is only useful for the audio frequency band.
 

someonesdad

Joined Jul 7, 2009
1,583
I've heard of people destroying their sound card by doing this. However, it probably wouldn't be too hard for some of the electronics experts on this board to put together some easy-to-construct front ends that would provide a reasonable amount of protection -- or provide some good links to existing projects. This could be a big help for some folks on a budget.
 

Thread Starter

count_volta

Joined Feb 4, 2009
435
someonesdad is right. LOL. I fried my onboard soundcard with it. Had to order a new one. I had a project due one day and was in a hurry and ignored the warning "Max 1V input to oscilloscope" Yea. killed it. So please be careful.

Anyway I got a real oscilloscope now. Here is what. Its not free, but its at least cheap, and I say from experience its very accurate, don't judge it by its outer appearance. Watch videos of it in operation on Youtube its awesome.

http://www.jyetech.com/en/default.php

http://www.youtube.com/watch?v=L-lwDoEee2I&feature=related
 

Markd77

Joined Sep 7, 2009
2,806
That looks quite tempting, odd that it is cheaper with all SMD components soldered that with just the MCU soldered.

Do you know if the preassembled and tested one comes ready to go?
I'm interpreting it as having the software installed but no bootloader so it can't be updated over serial.
 

Thread Starter

count_volta

Joined Feb 4, 2009
435
Do you know if the preassembled and tested one comes ready to go?
I'm interpreting it as having the software installed but no bootloader so it can't be updated over serial.
You don't need to install any software. I didn't feel like soldering it and possibly ruining it, so I got the preassembled one. Its all ready to use right out of the package. You take it out, plug a signal in, and away you go. There is a feature to transfer the signal display screenshots to your computer via serial, but I still need the cable to do that.
 

CVMichael

Joined Aug 3, 2007
419
Depending on the sound card you can do higher frequencies.

My sound card can record sound at 110 KHz, 16 bit (I actually did not try to see what is the limit, maybe it can even go higher ?)

But I don't see the point to use the sound card as a scope, the frequencies are way too low.
 
For the non-Windoze users there is a Linux package (works for me Ubuntu 10.04) called xoscope that accomplishes the same thing. Very cool application, I've found it quite useful.
 

sceadwian

Joined Jun 1, 2009
499
From personal experience, I find DC coupling REALLY REALLY useful, an AC coupled only scope has it's uses, but the lack of DC coupling throws it out the window as far as DC analysis goes.

I have never found a sound card that has a DC coupled input, although some do have DC coupled outputs for driving stereo headphone with decent bass (especially some modern Class D amps)
 

oidium45

Joined Apr 24, 2010
138
If you cannot afford a oscope, perhaps you could look into one of the usb options? They run around $100. An initial investment of $100 sure beats frying your computer or sound card...
 

retched

Joined Dec 5, 2009
5,207
I would get one of the $3 usb sound cards if you dont have the $100 to spend.

I however agree with oidium45. The soundcard input will limit you pretty good.

If you saved $100, save $288 and get a stand alone OWON PDS5022S. ;)

But, if you go the soundcard route, you should really protect your soundcard with one of these:
http://www.dealextreme.com/details.dx/sku.22475

Razor Concepts posted it in another thread. $2.14 with FREE shipping. So... its worth a try.
 
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