Linux PC as oscilloscope

[Allan Adler]

I've seen some free software for using one's PC under Linux as an oscilloscope.
Before I get bogged down trying to do this, I'd be interested in hearing
from other people who have used such software. I'm talking about RedHat
Linux, not RT Linux, so I'm concerned about real time problems. Also,
I don't know what kind of speed the oscilloscope is capable of. I have
two old EICO 460 oscilloscopes and I am inclined to believe that the
Linux PC as oscilloscope will be better than they are, but it would still
be nice to know definitely. More generally, what would be the closest model
oscilloscope to the PC oscilloscope in terms of its capabilities and
reliability?

Ignorantly,
Allan Adler
ara@zurich.ai.mit.edu

****************************************************************************
* *
* Disclaimer: I am a guest and *not* a member of the MIT Artificial *
* Intelligence Lab. My actions and comments do not reflect *
* in any way on MIT. Moreover, I am nowhere near the Boston *
* metropolitan area. *
* *
****************************************************************************

 

[DarkMatter]

On 07 Aug 2003 23:28:07 -0400, Allan Adler <ara@nestle.ai.mit.edu>
Gave us:

I've seen some free software for using one's PC under Linux as an oscilloscope.
Before I get bogged down trying to do this, I'd be interested in hearing
from other people who have used such software. I'm talking about RedHat
Linux, not RT Linux, so I'm concerned about real time problems. Also,
I don't know what kind of speed the oscilloscope is capable of. I have
two old EICO 460 oscilloscopes and I am inclined to believe that the
Linux PC as oscilloscope will be better than they are, but it would still
be nice to know definitely. More generally, what would be the closest model
oscilloscope to the PC oscilloscope in terms of its capabilities and
reliability?

Does this not also require that a data acquisition card be in the
PC?

I doubt seriously that the sample rate would be over 10MHz even.....
if that much. And the iteration of it will be quite "grainy" as well,
I'm sure.

There are really nice data acquisition cards out there for less than
$150, That'll do some VERY fast sampling rates.

Nat'l Instruments... yada yada yada.

 

[Jean-Michel Friedt]

Linux PC as oscilloscope will be better than they are, but it would still
be nice to know definitely. More generally, what would be the closest model
oscilloscope to the PC oscilloscope in terms of its capabilities and
reliability?

If you're talking of scope.c which is provided (or at least used to be)
with svgalib, then it is just a sound card sampler which displays the
recorded data on screen
=> your max sampling rate is something like 46 kHz and resolution is
around
16 bits. Nothing to compare with a real oscilloscope (assuming the LSB
of
your sound card is relevant).

Now depending on your application, the interesting aspect of such a
program
is that you can customize the trigger function (only start recording
when a
given event occurs).

Jean-Michel

 

[Blake]

Allan Adler wrote:

I've seen some free software for using one's PC under Linux as an
oscilloscope. Before I get bogged down trying to do this, I'd be
interested in hearing from other people who have used such software. I'm
talking about RedHat Linux, not RT Linux, so I'm concerned about real time
problems. Also, I don't know what kind of speed the oscilloscope is
capable of. I have two old EICO 460 oscilloscopes and I am inclined to
believe that the Linux PC as oscilloscope will be better than they are,
but it would still be nice to know definitely. More generally, what would
be the closest model oscilloscope to the PC oscilloscope in terms of its
capabilities and reliability?

400 bucks, 100MHz scope for Linux:
http://www.etcsk.com/linux/

A radio-shack 20Ms/S scope:
http://www.linuxtoys.org/pscope/pscope.html

The bottom of the second page has a bunch of links.

Blake


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[DarkMatter]

On Sun, 10 Aug 2003 13:15:48 GMT, Blake <bleverett@pants.att.net> Gave
us:

400 bucks, 100MHz scope for Linux:
http://www.etcsk.com/linux/

It isn't just software. It requires an EPP port.

That means that they have a device that you hook up to get the data.

100MHz and parallel ports don't seem to mix, to me. The device must
merely send a low resolution data stream to the scope, giving the
observer a dithered view of the real data.

Not what I would call high resolve. I'd bet that a lot of
information on a 100MHz signal would be unviewable to the user of the
product.