DSP Robotics Support

Hi BobF
I was aware of Lissajou's figures from way back so my comment was that I thought it was a great and original idea to do it in Flowstone. And it was!
In fact back in 1971 I was the DJ in a disco where we made all our own gear. One thing I made was a converted old monchrome CRT TV to display Lissajou figures. I used a dummy scan coil set for the EHT to be generated then used the original line and frame scan coils for x-y deflection of 2 incoming amplified audio signals.
I can recall one guy who seemed to be hypnotised by the display while we played a Pink Floyd track (it wasn't a 'pop' disco!).
Happy days!

Cheers

Spogg

For better syncing, I would use dual channel "mono to graph" primitive. It will use single tick, and output data will match.

Hi tester

Great idea! This seems to give a more stable display. It was BobF who created the original so much praise to his initial idea too.

Here's the updated version.

Cheers

Spogg

Hello gang,

Sorry for the delayed response, just back from holiday.
Thanks tester, your tip really does seem to improve things as Spogg has shown (thanks a million Spogg).

If you two, or anyone really, wants to help, I have a couple more ideas. How would you only select darker colours as the lighter ones do not show up very well, how can we make a colored back ground, and lastly, how could you overlay a second image? Fun stuff!

Later then and thanks again, BobF.....

Guys check this out

https://www.youtube.com/watch?v=oGbaAs7ASwE

OMG!

It seems the whole on-screen app is devoted to this stunning output.
It looks like a wave player with an unseen (?) track which sequences the type of effect and the settings for the chosen effect. There must be scripting of some sort I think so you can enter text and select 'fonts' -shapes.
It looks like the figure generator could be linked to the wave or independently defined. In mant parts of the video it seems to be synced to the beat but not linked directly to the sound but the music kind of matches the shapes to give the impression of linking.
I can imagine that in use this is similar to a video editing sofware like Videowave which I make use of sometimes. It's possible that there is actually NO linking and the creator has to make the figure sequence track manually for the whole video and it gets rendered and played back like a regular video.
Whatever is the case I really enjoyed it and I'm sure one of the geniuses on this forum could knock one up in a couple of evenings...
Cheers
Spogg

Hey BobF,

I know (or at least think I know) how your schematic works. But how did the original hardware xy-oscilloscopes work? You put a signal on x and a signal on y - and then? What is happening with those signals? Somewhere I read "Voltage of channel 1 is plotted along the x-axis, voltage of channel 2 along the y-axis". Is it really that simple?
I see 3 dimensions, x, y and time.
So channel 1 is plotted from left to right according to the time window and the value of each plot extends on the y-axis, just like a normal graph?
And channel two makes the same, just with switched axes (y-axis for time advancing, x-axis for the value)?

But why do we see nothing on a hardware oscilloscope, if the signals are exactly the same? Why is it a circle, when two same signals are out of phase by 90°? Etc.

Would like to understand this better, without having to read technical manuals with hundreds of pages

Spogg wrote:OMG!

It seems the whole on-screen app is devoted to this stunning output.
It looks like a wave player with an unseen (?) track which sequences the type of effect and the settings for the chosen effect. There must be scripting of some sort I think so you can enter text and select 'fonts' -shapes.
It looks like the figure generator could be linked to the wave or independently defined. In mant parts of the video it seems to be synced to the beat but not linked directly to the sound but the music kind of matches the shapes to give the impression of linking.
I can imagine that in use this is similar to a video editing sofware like Videowave which I make use of sometimes. It's possible that there is actually NO linking and the creator has to make the figure sequence track manually for the whole video and it gets rendered and played back like a regular video.
Whatever is the case I really enjoyed it and I'm sure one of the geniuses on this forum could knock one up in a couple of evenings...
Cheers
Spogg

Actually what you're hearing is indeed nothing more than the audio running through the oscilloscope, no joke! Check out the kickstarter page linked in the description; he want's to make a whole album like that. And someone is making software to convert 3D models into oscilloscope art! Apparently it's somehow even playable via MIDI. If it wasn't so expensive on the rewards scale I would buy into that.

Oh and by the way that software in the video is just FL Studio.

tulamide wrote:Hey BobF,

I know (or at least think I know) how your schematic works. But how did the original hardware xy-oscilloscopes work? You put a signal on x and a signal on y - and then? What is happening with those signals? Somewhere I read "Voltage of channel 1 is plotted along the x-axis, voltage of channel 2 along the y-axis". Is it really that simple?
I see 3 dimensions, x, y and time.
So channel 1 is plotted from left to right according to the time window and the value of each plot extends on the y-axis, just like a normal graph?
And channel two makes the same, just with switched axes (y-axis for time advancing, x-axis for the value)?

But why do we see nothing on a hardware oscilloscope, if the signals are exactly the same? Why is it a circle, when two same signals are out of phase by 90°? Etc.

Would like to understand this better, without having to read technical manuals with hundreds of pages

I think this might help answer your questions: https://en.wikipedia.org/wiki/Oscilloscope#X-Y_mode
It's basically what a "vectorscope" is.

Perfect Human Interface wrote:And someone is making software to convert 3D models into oscilloscope art! Apparently it's somehow even playable via MIDI.

Apparently some other guys are already much farther:
https://www.youtube.com/watch?v=aMli33ornEU

Still, what you linked originally, is a whole other story! It's actual music driving an xy-oscilloscope, and both visuals and audio is satisfying. Before you could either have nice graphics OR nice music, not both (when talking of xy-oscilloscopes). That is damn hot!

And thank you for the link. I already read it, but it doesn't explicitly answer the questions in my head (for example, with what time window does an oscilloscope work, how often is the display updated per second, etc.).