PC Sound Card Oscilloscope Software
Sound Card Oscilloscope Probe SoftwareLearn more about the software available in my book: Sound Card Oscilloscope - Build Better Electronic Projects. I cover two very capable software applications that turn your PC into a powerful oscilloscope and signal generator. If you want to buy a cheap but inexpensive USB based oscilloscope then you could do worse than the Hantek 6022BE USB scope.
As I said earlier in this project, there are some drawbacks to using your PC's sound card in this way. This includes:
Scope probe calibrationAs it stands neither the oscilloscope software nor the circuit that you just built is capable of calibration. That is to say the scope will display a moving signal but you will not be able to determine the strength or amplitude of the signal under test. In a future project I will show you how to build a simple circuit that will enable you to calibrate the PC Oscilloscope so look out for that. Possible damage to your PCBy using a pair of head-to-toe connected diodes we have limited the input voltage to the sound card. This will give you some protection but it will not guarantee to protect your PC against high voltage inputs. You should never apply signals of more than 10 volts to this probe circuit. Bandwidth limited to 20 - 20kHzThis is a limitation but nevertheless your simple and cheap PC based oscilloscope can be very useful if you have no other way of looking at your circuit waveforms. Here are some examples of the traces you can expect at different frequencies. They are displaying waveforms from a simple astable multivibrator circuit.
Here is the display with signals taken from an astable multivibrator running at 100Hz. The signals were taken from the collector and base of one of the transistors. Compare this to the traces from my elderly 100MHz Hameg oscilloscope displaying the same signals below.
The traces on the Hameg are cleaner as you might expect and the sound card traces are inverted. Apart from that the PC is providing a reasonable representation of the signal. Lets see what happens when we increase the frequency from 100Hz to 1250Hz.
At 1250Hz the PC is starting to round off the edges of the square wave from the collector and the triangle wave from the base. This is due to the limited bandwidth and inability to reproduce the harmonic frequencies present in a square wave signal. If I had used pure sine wave signals to test it on the you should see sine waves all the way up to 20KHz.
The reference signal on the Hameg provides a better representation of the test signals but it also cost me a lot of money. The PC scope is almost free.
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Comments (50)
But cant find the link ( lin adress ? ) tocharge on the computer ( for simulating the 2 channels of a osciloscope ).?
Could you answersto my mail adress ?
Thank
Your
Bes t regards
Patrick Montpellier France
1. To which port of my do I connect the output probe to? headphones or microphone or line-in?
2. For my experiments, I may have to operate around a voltage of 15 to 22 volts. Will this pose a threat to my sound card?
I want to make this oscilloscope to test sensors and wiring on my car, but the cars voltage is between 12v and 14.4v.
Will this work for me?
Or, are there any changes that I can make to the design so that it will cater to my needs?Thank you.
Can I use the above PC Sound Card based oscilloscope to display the ECHO & TRIG waves of an Ultrasonic Sensor Module(HC SR-04) ?
I see under your other project(s) on this website you are using HC SR-04; So I assume that you are better aware of the details for the same.Regards,
Saurabh
it seems to work right. I have been meaning to ask what the difference is between the poly box ones you use and the ones I used.
still much to learn, but having a great time with your book so far. now on to building the cali/generator. thanks Steve
Steve
Steve
Thank you
i have a doubt thoughHow and why are we selecting a 3.3 k ohm and a 470k pot?
another point that i was wondering about is how does the two zener diodes work.P.S. im a noob in electronics :P
What is a 3K3 resistor, do you mean a
3K Ohm resistor. excellent article
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