Sound card scope SW with smooth roll mode?

To be clear, I don't think Audacity will do what you want. The smooth- scrolling item is from their wishlist (suggestions for future features), not from the list of current features. The download link I gave is for the whole program, not a smooth-scrolling add-on.

Protip: *Everything* has software in it, these days. :)

In my experience, lashing things together with scripts (shell, Perl, batch, whatever) works pretty well for prototype-y and one-off things. The time it takes you to learn how to do this is way less than the number of man-hours of software development that you get for free when you download an existing package.

Every once in a while, the lash-up it works well enough that you can put it in production. If it doesn't (usually either it's not fast enough or needs a slicker user interface), then yeah, it's time to break out the compiler. Even in that case, the lash-up often shows you something you didn't think of about the problem you are trying to solve.

Matt Roberds

But the managers told him to do that, 'cuz hardware, gosh, that's going to take some time to build, but software, *whooosh*, it's like magic! Right?! ;-)

Tim

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ry

Well what are ya doing?

A degree of phase difference at ~10kHz... that's not hard.

George H.

You can use the soundcard to create a stimulus, but you should be using one channel of the soundcard input to record the stimulus, and then the other channel to record the output. Your description doesn't read like that.

This itself is confusing: "I (hopefully ...) can > feed this into some other display spftware via the WAVE function in > MS-Windows, the one where a device can read audio from some other source > instead of the physical sound card jack. Because the sound card data > processing is already done at that point."

Wave is a format, not a function. It is found in windows and linux.

You digitize the two channels. You process the audio in something like Audacity and can produce another wave file. With sox, you can read the file and plot it if need be.

There is really nothing great about sound on windows. In fact, the drivers suck so badly that you need asio drivers if you expect low latency.

Linux is far more flexible. Further, the programming tools on windows are either lame if free or expensive if good. [Try pricing Visual Studio.] Not so with Linux, which has free development tools and libraries. But nothing you have mentioned thus far sounds like you need to write any software. Just pipe stuff between existing programs, at least on linux.

urce

Wave is also the name of some audio multimedia functions in the Win32 api

as in WaveIn, WaveOut etc.

y.

Not surprising that a desktop OS isn't exactly hard realtime out of the box

Almost all the tools on Linux is available for windows as well, just takes a bit more than a single commandline to install them

There's free Visual studio, doesn't have all the tools but it's a compiler and an editor

-Lasse

It can, but their support said this is not a slam dunk. Needs a special driver, one they don't have. Not so good.

I'd like to keep this on Windows though.

I've got a whole pound of solder. That ought to do :-)

Yup :-)

I have Audacity, and it sure doesn't look promising for this case.

I know. But the good stuff is all point and click, not writing hundreds of lines of code.

Sure, and that would do. But I have zero experience in such scripts.

I lean more and more towards doing this in hardware. Because then I know it works.

That's what I was planning to do. It's too risky to do a phase comparison without knowing how much jitter the output might add in.

That is a last resort thing and would take away the option to measure the stimulus. Unless I add another sond card which should be easy.

Yeah, I just meant the "whatever the WAVE input in the Windows sound mixer uses" link :-)

Ok, but on this I need to use Windows, because the computer has to run some other stuff as well.

I've run aground with some of the Linux open source stuff, often because it was not at all on a professional level. CAD for example. But this time it has to be Windows because other Win-based things must run in parallel and none in our group has Linux exposure. Ok, I have a little but it's not much to write home about.

That's the ones.

It does not have to be in this case.

And then there is the Weller station :-)

In a nutshell: An audio tone at a few kilohoitz goes into a resonant structure. Back out comes a phase shifted response. Plus the stimulus if I can keep the 2nd sound card input for that. This will now be full of man-made noise from AM transmitters, switcher power supplies, dimmers, thunderstorms and whatnot. So I need to bandpass filter the phase-shifted signal and the stimulus feedback, down to 100Hz bandwidth or so. Then something has to compare the phase difference and send that value to a display at 100samples/sec or faster. The absolute position of the phase is not critical and needs to be subtracted, only the changes are important.

Some other things need to be measured as well but that's secondary for now.

It can all easily be done in software. If there was something that is easy to use. And maybe there just ain't.

Obviously it is for the PC software, no idea why.

Yeah, I have the "free" Visual studio 2010. It is just ugly compared to using linux.

The linux tools on windows are usually just cygwin hacks, though audacity I believe it native. That doesn't mean they will work well since windows itself is the problem. At some point in the development, they cut the latency back on windows. That is, the current kernel is low latency.

I have to say I'm impressed at what is being put out in the OS community on .net/mono. Anything not to have cgywin hacks.

DosBox has saved the use of some old 16 bit code for me. I was trying to fix all the "depricated" source crap to recompile when I remembered dosbox. I've also bought some GOG (good old games) which uses the dosbox project.

In hardware I trust!

It still isn't clear to me what you are trying to do, but one thing to keep in mind for windows is VAC (Virtual Audio Cable). It is a ripoff of what you can do in linux for free, but if you really need to use windows, it can come in handy. Basically most windows programs aren't set up for piping. VAC is a way to "jack" together programs. That is, feed the audio output of one program into the audio input of another program in real time.

The problem with software from fly by night companies is once they get paid, the support becomes s**te. There are exceptions of course, but it has been my experience that garage shop software is not as good as running open source software.

I have no first hand knowledge of VAC. I've just heard of it mentioned as a means to do linux type trickery on windows.

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Hmm I wonder why we haven't heard from Bob Masta and his daqarta software. (I've never used it...)

Anyway it sounds like a perfect job for a lock-in. (Which I'm sure you've already thought about.)

George H.

Just saw this thread...

Do you mean the data processing is smooth, or the 'display' is smooth? Using Windows I don't see how you can EVER get control over the display to that extent.

However, for smooth data processing using a soundcard, have you looked into ASIO? out of Germany. That software to acquire data coupled with C/C++ written for real-time operation I think you can get your 10mS processiong with very little latency, never miss a data point. Also look into the free FFT software for processing. octave uses that algorithm [I bleieve] and it is a SCREAMER! You would not believe the performance possible.

After a hint from one of us via PM I have contacted Bob. We'll see if his software can be coaxed into doing this..

A lock-in amp is essentially a glorified narrowband phase and amplitude detector. I know how those are done in HW as well as SW. Thing is, I have yet to find an easy enough and affordable "Lego-style" toolbox for Windows that takes soundcard data and where I can freely do I/Q demod, filtering, 1/tan(X/Y), non-triggered rolling display and all this stuff.

Oh yeah, I do. With a bag-o-parts from Digikey almost anything is possible.

Essentially this but preferably not with LabView:

Thanks. This might be an option if I can't find a solution that combines enough math horsepower with decent enough graphics output.

The display must be smooth. Data can be transferred in junks, that doesn't matter.

Sure you can. I have numerous examples here, software that does thinks like realtime scope display on a PC, spectrum analysis with waterfall diagrams, and so on. Hey, you can even watch a movie on a Windows PC :-)

"coupled with C/C++ written for real-time operation", that's where my limits are. I can't do that, I am a HW guy. Could contract that out but it would have to be a local person. I've tried Octave in the past and I wasn't too enthused but maybe I should look again as that was many years ago.

Hmm, thou shalt not switch languages more than 10 times in the morning on only one cup of coffee ... should say "chunks" and "things" :-)