The Software used in Oscilloscopes

We now take a look at the software used in oscilloscopes.  The software used in oscilloscopes is an important element to understand.

There are two basic components of a PC based oscilloscope:  The hardware side and the software side.  The hardware is usually, at least in the general case – except  in the case of the USB based oscilloscope where the hardware is external to the PC and plugs in via the USB port – is a board either already in the pc or subsequently added for the purpose of converting it for oscilloscope functionality.

In an obvious and simple case is one where the sound board is used as the input processor for a class of oscilloscopes intended for measuring, viewing and recording repetitive wave forms such as sine waves or sound patterns.  One involved in audio measurements, for example, would be a user of such an instrument.   The soundcard or board has the necessary input to catch the analog signal, amplify it and convert the output to a digital representation that can be then further manipulated as necessary to display, condition, calculate, process or distribute, etc.

There are other boards or cards that can be utilized depending on what purposes the oscilloscope is put to.   Digital storage and digital troubleshooting methods are often the end result and the cards employed may very well be suited for sampling and storing such data for future retrieval, processing and analysis.

There are specialized manufacturers who make cards for amplifying, digitizing, buffering and so on.  That will be the subject of another treatise on another day!

Here are some examples of the software that might be needed for various applications:

Audio Testing:  - Audio Spectrum Analyzer for Real-time, FFT, Oscilloscope, Frequency counter, voltmeter, noise and distortion meter, phase shift meter. Multi-Tone Sound Frequency Sweep Generator. White, pink noise.

FFT:  - Spectrum analyzer designed for time-frequency browsing and scientific data visualization. Oscilloscope waveform, statistical histogram, accumulated spectral trace,Weak Signal reception, continuous data logging, FFT Analyzer and specialized measurement windows.

Software for these uses may be supplied by the manufacture of the card.  It may also be freeware from others who support various applications for their PCs or oscilloscope applications.  In some cases, such as Pico  Technology, they provide SDKs (Software Development Kits) which allows users to write their own software variations to meet special user requirements.  Development kits are often available in various languages allowing the user to integrate the software easily into an embedded or extended system.  Visual Basic , C, C# and C++ are common languages used  for software code writing.   Such software often is written in the form of a driver for a certain set of hardware cards or PCs which allows for easy integration and fine-tuning.

Let us take a look at a simple system.  Such a system being referred to is the “Poor Man’s Oscilloscope” and is based around a conventional PC with a soundcard already installed in it.

Connection to the PC:  The soundard will have an input, usually blue in color, which allows for audio input from outside sources such as a cd player, MP3 or iPOD device.  An audio cable with the miniature stereo plug can be adapted by stripping the opposite ends and baring the three leads, ground, left and right channel such that it can be used as a probe for connecting into the unit under test.

Software:  The software package used in the “Poor Man’s Oscilloscope” is from GoldWave.  This software is compatible with most MS OS versions and Unix but not Mac OS X, sorry.  Goldwave is available as a download at CNET and comes in a trial version or can be purchased for a nominal cost.

From GoldWave:  They say this, “GoldWave is a professional digital audio editor. Use it to play, edit, mix, and analyze audio, or apply special effects, such as fade, equalizer, echo, reverse, time warp, noise reduction, silence reduction, pop/click filter, voice over, etc. Record new files from cassettes, albums, radio, or microphone and restore and enhance them using the wide range of filters and effects. Digitally copy tracks directly from audio CDs to edit or remix them. Convert all your iTunes  M4 songs to MP3, match volume levels between songs, trim leading and trailing silences, adjust equalization to prepare your songs for a perfect MP3 CD or before copying them to your MP3 player.”

Further, “Displays a variety of useful real-time visuals during playback and recording. Supports MP3, iTunes M4A, WAV, WMA, Ogg, and many more formats. Includes built-in tools, such as Batch Processing, CD Reader, File Merger, and Effect Chain Editor. GoldWave does it all, yet it’s fun and easy to use.”

Below is what it’s interface screen looks like.

Note:  Source of “Poor Man’s Oscilloscope” is from Rob Crockett.  His web with further information about his experience with GoldWave is at http://www.ledametrix.com/oscope/index.html.

The software used in oscilloscopes is an important aspect of these instruments.

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