school project needs help

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uchwoody
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school project needs help

Post by uchwoody » Fri Jun 18, 2004 8:01 pm

Hi ev'ryone. I'm designing (or I'm supposed 2 design a pc-based oscilloscope) ie one that can take a signal, process it and feed it 2 a pc for display. My problem is that I don't really have any ideas as to how 2 go about it. I thought of using an ADC in a circuit, but I can't figure out how 2 build it.
I'm also supposed 2 design the display software, but I want 2 handle the signal processing part first.
Any ideas?

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dacflyer
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Re: school project needs help

Post by dacflyer » Sat Jun 19, 2004 6:47 am

Ummmm these items are already built and on the market...think i saw 1-2 in the N&V magazine..<p>i do not know if you'd want one or want to build one..Hmmmm

Equinox2355
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Re: school project needs help

Post by Equinox2355 » Sun Jun 20, 2004 4:49 pm

Well I think I found a resource that will help you. this is a circuit and it even has C code for displaying what you need. I hope this helps.<p>http://www.electronicsforu.com/efylinux ... oscope.pdf<p>-Mike

uchwoody
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Re: school project needs help

Post by uchwoody » Mon Jun 21, 2004 3:26 am

<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>Originally posted by Equinox2355:
Well I think I found a resource that will help you. this is a circuit and it even has C code for displaying what you need. I hope this helps.<p>http://www.electronicsforu.com/efylinux ... oscope.pdf<p>-Mike<hr></blockquote>

uchwoody
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Re: school project needs help

Post by uchwoody » Mon Jun 21, 2004 3:28 am

<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr>Originally posted by Equinox2355:
Well I think I found a resource that will help you. this is a circuit and it even has C code for displaying what you need. I hope this helps.<p>http://www.electronicsforu.com/efylinux ... oscope.pdf<p>-Mike<hr></blockquote><p>Thanx a million. I'll do some homework on d lead.It'll save me a lot of stress. Keep u guys posted.

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jollyrgr
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Re: school project needs help

Post by jollyrgr » Mon Jun 21, 2004 5:57 am

What kind of frequency range do you need? Audio? RF? Most desktop computers have soundcards right on the motherboard. Most others will accept a PCI or USB soundcard. There are numerous programs (shareware and freeware) that will display the soundcard input on an O'scope window. So my approach to this attack is to suggest using some sort of prescaler to take the higher frequency signals and shift them down to audio frequency range and use the soundcard line input. You would then use voltage dividers and/or OP amps to scale the voltages as needed. The most complex part of the circuit is already done for you. In fact it might be a novel approach to the task since most PC based OS (Linux, DOS, and Windows) have drivers written for the soundcards. All you need to do is scale the incoming signal to the bandwidth of the soundcard. Then, based on the "prescale" of the hardware, adjust the software display. You could take a second approach and use a USB soundcard chipset and design the entire soundcard/prescaler into one box. Talk to your adviser about this before hand. He or she might want you to design the entire ADC circuit from scratch. But to my line of thinking this would be reinventing the wheel.
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Equinox2355
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Re: school project needs help

Post by Equinox2355 » Mon Jun 21, 2004 10:54 am

No problem woody glad to help, your just lucky i stumbled across it.<p>-Mike

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jollyrgr
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Re: school project needs help

Post by jollyrgr » Fri Jul 02, 2004 2:24 pm

Here are some links for a soundcard/PC based scope. I've not tried these myself but they may be useful:<p>http://downloads-zdnet.com.com/DXVU-Met ... ag=lst-0-2<p>http://downloads-zdnet.com.com/DSSF3-Li ... ag=lst-0-4<p>http://downloads-zdnet.com.com/Scope2k/ ... ag=lst-0-6<p>These are programs that are meant to analyze SOUND. You can play with these as examples. You will be scaling higher frequencies down to audio level to analyze them. These are provided as EXAMPLES to get you started in the right direction.
No trees were harmed in the creation of this message. But billions of electrons, photons, and electromagnetic waves were terribly inconvenienced!

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