Pc Sound Card as a Function Generator and Oscilloscope
Use of Sound Card as an Oscilloscope and Function Generator
Saad Pervaiz
LUMS School of Science and Engineering
Winter 2010
Keywords
MATLAB. DAQ . Sound card. Oscilloscope . Signal Generator .
Sound Card
Sound card present in personal computers facilitates the input and output of audio signals, under the control of a driving software e.g. in multimedia. This device can be used as an oscilloscope for signals up to a frequency of 20 kHz.
The following text shows how sound card can be utilized as an oscilloscope and as a signal generator using the Data Acquisition Toll box provided by MATLAB. Data Acquisition tool box needs to be installed for this purpose.
We will be using two channel sound card for this purpose. The input signal is provided in the jack named
“mic” by the use of a two channel probe, and the output is taken from the “earphone” jack.
1. AS OSCILLOSCOPE
Scopes Provided by MATLAB
The following text emphasizes on the following two GUI for oscilloscopes provided by MATLAB
1. Daqscope
2. softscope
Daqscope
Daqscope is a simple scope that displays the waveform of the input signal from either of the channels, and provides options for the maximum and minimum limits of the waveform.
This scope can be initiated by typing the following keywords in the MATLAB command window: daqscope The following daqscope window appears:
The buttons at the top left corner provide the start and stop control.
User can select the required channel; can modify the sampling rate, scale. It also provides the Auto set option which adjusts the amplitude and the x-axis scale according to the signal being provided.
Following screen shot shows the oscilloscope in action for a sine wave of 1 kHz.
Softscope
This is another scope provided by MATLAB, which provides many more features than the daqscope.
The following text throws some light on a few of these features.
Softscope can be initiated by typing the following keywords in the command
Saad Pervaiz
LUMS School of Science and Engineering
Winter 2010
Keywords
MATLAB. DAQ . Sound card. Oscilloscope . Signal Generator .
Sound Card
Sound card present in personal computers facilitates the input and output of audio signals, under the control of a driving software e.g. in multimedia. This device can be used as an oscilloscope for signals up to a frequency of 20 kHz.
The following text shows how sound card can be utilized as an oscilloscope and as a signal generator using the Data Acquisition Toll box provided by MATLAB. Data Acquisition tool box needs to be installed for this purpose.
We will be using two channel sound card for this purpose. The input signal is provided in the jack named
“mic” by the use of a two channel probe, and the output is taken from the “earphone” jack.
1. AS OSCILLOSCOPE
Scopes Provided by MATLAB
The following text emphasizes on the following two GUI for oscilloscopes provided by MATLAB
1. Daqscope
2. softscope
Daqscope
Daqscope is a simple scope that displays the waveform of the input signal from either of the channels, and provides options for the maximum and minimum limits of the waveform.
This scope can be initiated by typing the following keywords in the MATLAB command window: daqscope The following daqscope window appears:
The buttons at the top left corner provide the start and stop control.
User can select the required channel; can modify the sampling rate, scale. It also provides the Auto set option which adjusts the amplitude and the x-axis scale according to the signal being provided.
Following screen shot shows the oscilloscope in action for a sine wave of 1 kHz.
Softscope
This is another scope provided by MATLAB, which provides many more features than the daqscope.
The following text throws some light on a few of these features.
Softscope can be initiated by typing the following keywords in the command