software > Scope

Scope is a time- and frequency-domain software oscilloscope for unixlike operating systems such as linux and FreeBSD.

To install the program, first download and unpack the file scope.tar.gz, then unpack it using the command tar -zxf scope.tar.gz, then do cd scope_dist and follow the instructions in the manual page, which is reproduced at the bottom of this web page.

For many years before I wrote Scope, I was using an open-source program by Paul Lutus called fftexplorer, which did almost everything I needed for the physics lab classes I teach. However in 2008 Lutus discarded the version of the program he'd written in C++ and started over from scratch in Java. The new Java version doesn't do what I need, and that's why I wrote Scope. Although Lutus no longer makes the old vesion of fftexplorer available on the web, it was licensed under the GPL, so it's legal to redistribute it and/or fork it. On my web site I'm making available copies of the source code and a binary compiled for 32-bit Linux. To get the binary to work, you need to install the Qt libraries, which I do on ubuntu by installing the kdelibs package. On recent versions of linux (e.g., Ubuntu 10.10+) that no longer have OSS emulation by default, you need to install the aoss utility (e.g., on ubuntu by installing the alsa-oss package) and invoke fftexplorer as "aoss fftexplorer." The binary will presumably stop working at some point when a future version of Linux breaks backward-compatibility, but it still runs fine as of 2010 on Ubuntu Lucid. The source code apparently needs to be modified in order to compile with current versions of Qt (and this is why Lutus got mad and abandoned the C++/Qt version). If anyone with the necessary skills would like to get the source code to compile, that would be great, and I would be happy to host a forked version here.

man page

scope(1)                          scope 0.3.0                         scope(1)



NAME
       Scope - a software oscilloscope for time and frequency domains

INSTALLING
       Scope should run on any unixlike system, such as linux or FreeBSD. It
       depends on the gtk2-perl library, which can be installed on a Debian or
       Ubuntu system by doing:

               sudo apt-get install libgtk2-perl

       Then install Scope itself by doing:

               sudo make install

       Frequency mode will not work unless you also have the Math::FFT library
       installed. For convenience, a copy of this library is packaged with
       Scope and is installed automatically if you don't already have a copy
       installed.

USE
       To run the program, just type "scope" at the command line. It starts up
       in frequency mode by default, displaying a sound spectrum from the
       microphone input (/dev/dsp on a unixlike system). If you get an error
       starting up the program in recent versions of Linux (e.g., Ubuntu
       10.10), try using the command "aoss scope" to start it. Some versions
       of Linux, ubuntu 10.04 in particular, seem to have totally broken OSS
       support, and therefore will not work at all. To get aoss on ubuntu, you
       may need to install the ubuntu package alsa-oss.

       In either frequency mode or time mode, you can click on the Freeze/Go
       button to freeze the display, and then again to start collecting data
       again. The Frequency/Time button toggles back and forth between
       frequency mode and time mode.

       In frequency mode, the x axis is frequency and the y axis is the
       absolute value of amplitude.  You can switch the y axis between linear
       and log scale by clicking on Log/Linear Y.  You can change the
       frequency region that's displayed either by using the Zoom In and Zoom
       Out buttons or by clicking on the graph to get an extreme close-up of
       that region and then clicking again to see everything.

       Time mode is currently very primitive. There is no control over the x
       and y scales, and no provision for triggering.

AUTHOR
       Scope was written by Ben Crowell,
       http://www.lightandmatter.com/personal/.  It incorporates some sample
       code by perlmonks user zentara at
       http://www.perlmonks.org/?node_id=583578.

COPYRIGHT AND LICENSE
       Copyright (C) 2010 by Benjamin Crowell.

       Scope is free software; you can redistribute it and/or modify it under
       the terms of the GPL, or, optionally, Perl's license.

       For copyright information on Math::FFT, see
       http://search.cpan.org/~rkobes/Math-FFT-1.28/FFT.pm.



0.3.0                             2012-05-03                          scope(1)