Manual for the sound card oscilloscope V1.40
C. Zeitnitz english translation by P. van Gemmeren, K. Grady and C. Zeitnitz
This Software and all previous versions are NO Freeware! The use of the software and of the documentation is granted free of charge for private and noncommercial use in educational institutions. Support the further development of the program byobtaining a private donation license! Any commercial usage requires a corresponding license. LabView and all its components © 2011 National Instruments Corporation. All Rights Reserved.
Details about the licensing terms can be found in the file license_NI.txt in the installation directory
For retail versions contact the author. © C. Zeitnitz 2005-2011 Web-page:http://www.zeitnitz.de/Christian/scope_en
The sound card oscilloscope is a digital oscilloscope with an integrated signal generator, frequency analysis (FFT) and wave file recorder
Windows 2000 , XP, Vista or Windows 7 A PC with a sound card installed. 50MB of disk space
Unpack the ZIP file in any directory and run setup.exe. The program can be started thereafter through the program menuof the Windows operating system. Windows Vista/7: Make sure, that the directory – from a previous installation of the program – C:\Users\AppData\Local\VirtualStore\Program Files\scope is removed before the first start of the program. Otherwise wrong configuration and language files might be used.
This software can be used for the display and analysis of sound waves. The data canbe recorded both directly from the sound card (with a microphone or LINE input), or from a source such as a CD or Mediaplayer. The input to the oscilloscope is defined by the Windows sound mixer (see below). The software obtains its input data for the sound card via the Windows interface. It does not communicate directly with the sound card. Therefore sound card problems should be troubleshot atthe operating system level. The user interface is arranged like a conventional oscilloscope. However, in the program window, additional XY display, frequency analysis, and settings are provided.
C. Zeitnitz 06/2011
The software shows the left and right channel of the sound card in the oscilloscope window. The left channel is represented as a green line and theright channel as a red line. In the user interface window there are knobs and input windows for the following three functions: Amplitude, Time, and Trigger.
Figure 1: Soundcard oscilloscope
3.1.1 Amplitude settings The amplitude scale of the two channels can be set independently as well as synchronized. The latter is enabled at program start-up and can be disabled by un-checking “Sync CH 1&2” onthe front panel. In the case of independent channel control, the active channel has to be selected by the button “Select CH” (see Figure 2).
Figure 2: Amplitude settings and channel offsets The amplitude values are given in units per division of the oscilloscope screen and are displayed for both channels above this screen. The amplitude value corresponds to the digitized sound level divided by32768. This represents the 16Bit resolution of the data, which are taken with the sound card. Due to the different settings of the volume in Windows the absolute sound level cannot be determined directly! Therefore the presented values are to be understood in arbitrary units. The amplitude setting refers both to the oscilloscope window and to the XY graph. An offset can be assigned to eachchannel individually via the appropriate input window; thereby the two traces can be separated from each other. A click into one of the offset fields will result in two horizontal cursors to show up in the oscilloscopes screen. The offset can now be changed by moving these cursors with the mouse, or by entering a value into one of the fields. If the signal of the channel is outside the visible window...