rPi oscilliscope

[TubsAlwaysWins]

Anyone know what would be needed to turn my raspberry pi 1 into a oscilliscope? The idea would be that I would have the pi mounted somewhere with a monitor on my wall. Then the audio would come out of my PC, into the pi, and then back to my speakers.

What program would I need?

Would it be possible for the music to seamlessly go through my pi and then to my speakers? (I guess I could just use a splitter tho)

So it would be PC>rPi>speakers

[Electronics Wizardy]

audicaty would work. This won't be accurate at all. Id just buy a old crt scope if you want a scope.

[dany_boy]

Raspberry pi doesn't have enough processing power to serve as anything close to a decent usable scope without some external hardware which does all the heavy lifting or some custom kernel module. Running an "Oscilloscope simulator" on windows on your audio signal would be much easier and yield better results. That being said, if you still insist on doing it, this instrutable should do you good: http://www.instructables.com/id/PiScope-Raspberry-Pi-based-Oscilloscope/. Keep in mind you will need to fiddle about with some electronics, as well as computer science stuff, and it will take you some time to get up and running.

Cheers and good luck!

[dany_boy]

BTW, are you sure you are looking for a scope? Or are you trying to refer to an spectrum analyser? The scope shows amplitude vs time, while the spectrum analyser shows amplitude vs frequency. For audio that means they will display vastly different images:

Example of an audio signal on an oscilloscope (a very bad example but an example nonetheless):

Example of audio signal on a "tacky" spectrum analyser:

Cheers!

[steffen_anywhere]

@TubsAlwaysWins @dany_boy makes a good point with the spectrum analyser vs. scope... I understand you're only using this for low frequency signals (up to 20ish kHz, because audio), and only for the looks, not for accurate measurements. So it really depends on what you're looking for. Imo, a spectrum analyser for audio is waaay cooler, since a live graph of a spectrum 'reacts' to the audio and gives a visual feedback that 'feels' like the audio you're listening to. All audio visualisers are essentially spectrum analysers with a fancy/cool design. I personally do prefer the standard frequency against amplitude graph though . The scope output of an audio signal looks like what you see in digital audio workstation software such as Logic in the timeline.

 

@dany_boy Since it's only audio, the Raspberry Pi should be able to handle it just fine. FFT isn't very demanding. However, I'm not sure whether the rPi has a built-in audio input, or if you need a USB solution. In any case, getting it all to work nicely will probably require a lot of software work. But it's a cool project, so good luck @TubsAlwaysWins!!!