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Picture of Simple PC oscilliscope
Sometimes when I build simple ttl (Transistor–transistor logic) circuits I like to see the results of the output. An example would be the pwm (Pulse-width modulation) that might control a robot motor. I do not have the money to buy an oscilloscope. so I am using this project to fulfil those needs.

Note I am assuming you know how to use this set up. If you are not sure, please get a professional to help. If you are unfamiliar with electronics do not do this without help of a professional. Improper probes could destroy your computer, what is connected to your computer, and as well as not be safe.

Step 1: Input probe.

You may want to build this input probe from the first diagram.$$Search is a good place to go to get equivalent part numbers.  Also included are other probes that are not as system safe.

Quote from linuxquestions
I made a little progress....
I started first with using the line in jack. I made a probe with a 1 meg resistor inline. The tip of the stereo plug is the left channel or channel 1 on Xoscope display. So the ring is the right channel or ch. 2 on the display. I only used one channel to start with. I used the Sleve as ground. I found the line jack seems work a lot better "cleaner" than the mic input.
With xoscope running, trigger off, I opened Kmix and selected the red button under "line" and went over and selected the green button above "IGAIN" and set the gain mid way and it started to work. This was after much knob dicking and fiddling around without a clue.
I seemed to have bleed over from the other channel, but I think its just the setting of the scale I used 1/5 and the noise dropped way down. I think being familure with how it works will make it easier to use.
I think its possible to make a 555 timer oscillator maybe with some clipping diodes to create a voltage reference?
PabloAB3 years ago

Did you consider and the GUI: PulseView ( )? Looks more powerful and friendly.

Computothought (author)  PabloAB3 years ago

I just wanted to use what was in the repo and easy to install.

ifernandez35 years ago
gracias . bien explicado.vamos a ver como podemos armarla.
Computothought (author)  ifernandez35 years ago
Your welcome!
profpat7 years ago

this is really simple! great instructable!
Computothought (author)  profpat7 years ago
Thanx, we appreciate the comment.
pfred27 years ago
This is really cool! I have a couple of oscilloscopes and I still think it is cool. But then again I just like oscilloscopes I guess. I can get this for Debian Lenny even. I just checked with:

pfred1@spot:~$ aptitude search xoscope
p   xoscope                         - digital oscilloscope

Now I have to see what the difference between a TL072 and a TL082 is to see if I can use some of the ICs I already have here. Texas Instruments seems to think, "The JFET-input operational amplifiers in the TL07x series are similar to the TL08x series, with low input bias and offset currents and fast slew rate."

Hmmm, sounds promising to me. Now that I'm looking at the schematic again I might even have the original book it came out of. The Art of Electronics sounds awfully familiar to me.

Thanks for writing this up. I've heard of this stuff but never really looked at it too closely before. I just might have to try it out someday here.
Computothought (author)  pfred27 years ago
eefmf8 years ago
Please try the PDF and tell me if you agree the PDF is not working.
There may be something wrong at my computer.
pfred2 eefmf7 years ago
It sure seems broken to me here. I just tried to download it, that netted me a 0 byte file, so then I tried to just view it, and that got me a blank page. Using

wget ""

gets me something, but it isn't a PDF file, I don't know exactly what it is.

pfred1@spot:~/Downloads/XoSCOPE$ head Simple-PC-oscilliscope.pdf

I'm lodging a complaint with the management around here, that I do know!
Computothought (author)  eefmf8 years ago
Please direct your issues to the site administrators. I have no control over what you can or can not get.
eefmf8 years ago
Print PDF is not working.
Please fix it.
Computothought (author)  eefmf8 years ago
if you are talking aobyt Instructables, you need to direct you comments to the admin. if you are talking about Xoscope, I did not write the software. you might be able to get in touch with the authors here: