AUDIO OSCILLOPE WITH SOUNDCARD AND
SOFTWARE WRITTEN IN PYTHON
(2011-2018)
KLIK HIER VOOR DE NEDERLANDSE VERSIE
The audio oscilloscope program.
Audio oscilloscope with soundcard and software written in Python
Often you do need just a simple oscilloscope, only suitable for audio frequencies. In that case, this is a simple and cheap solution. The maximum frequency depends on your soundcard and it's maximum sample frequency. The sample frequency is often a standard value like 44100, 48000, 96000 and 192000 Hz. But you will notice that you can also program all kind of other values for the sample frequency. How is that possible? In Windows is a routine implemented that converts the sample frequency of the soundcard to your desired sample frequency. By means of interpolation, the values of the samples are calculated from the sample values from the soundcard.
When selecting the knob "Setup", you can program the sample frequency and also activate the "AD offset correction". Some old soundcards do have a huge DC offset, that is corrected then. With newer soundcards you do not have this problem or you can enable or disable the offset correction in the driver software.
There is no triggering for long sweeptimes. Only one trace is read and then the trace stops. Then you can have a detailed look of the trace with the knobs -Time +Time -View and + View. A disadvantage is that you cannot stop the program during reading a long trace. And for the rest it is just like all other software: Play and try!
Probe for the oscilloscope.
Probe for the oscilloscope and calibration
A simple probe with an impedance of 1M ohm can be made by yourself. No correction trimmer for the frequency is needed, that is only required for high frequency probes. For the calibration you do need a signal of a known level (for example a square wave signal from a 5 volt TTL IC) and adjust the recording level control in Windows so that the displayed level on the screen is correct. Or perhaps that you also have to change the values of the resistors R2 and R3 of 1k ohm and 2200 ohm.
An oscilloscope is a very important measuring device.
We can make a simple one with a PC and Python software!
SOFTWARE
Before you are using this program, you have to install Python. That is very simple. But read first something about Python by clicking the following link:
WHAT IS PYTHON AND HOW DO YOU INSTALL PYTHON
As the source code of Python is written in ASCII, it is very simple to modify the program to you own requirements. Think for example about the size of the screen, the colors etc.
Required Python version:
Required external modules (site-packages for the correct Python version!):
Download here the Python oscilloscope program by clicking the link here below:
Index PA2OHH