Redpitaya Forum

This is a copy of Ulf Holt's question from the old discussion pages
Rok

I have tried to set up Generator and oscilloscope to generate lissajous figures, but I cannot figure out how to do it. I want to show this to my grand son to make him interested in electronics, and I'm not very used to oscilloscopes. I know this can be done by Math Lab and some programming, but that's not what I call "real life".

Best regards

Ulf

Ulf,
I believe the intention was originated in the update "Playing Curves", right?
In order to establish the mechanism and setup itself - did you try to run the previous example - the one dealing with interpolation?
http://blog.redpitaya.com/?p=58

It is not that you would have to do the interpolation. As long as you can generate and acquire signals and print their graph in Matlab, you're fine. The setup is almost the same with Lissajous.
I hope this helps.
Best, Rok

Hi Rok.

THank you so much for taking time looking at my question.

When I was playing with oscilloscopes at the University about 30 years ago, I seem to remember we plotted on signal "Using an oscilloscope that could plot one signal against another (as opposed to one signal against time) to plot the output of an LTI system against the input to the LTI system produces an ellipse that is a Lissajous figure for the special case of a = b" as they explain in Wiki.

I cannot see how this can be done with Redpitaya, or am I missing someting?

Regards

Ulf

Hey Ulf,
The principle is just the same - just in this case the Lissajous are not drawn by Red Pitaya directly, but externally in Matlab. Still they are generated (2 sine signals) by Red Pitaya via DAC outouts and then acquired to Matlab and plot - Ch1 vs. Ch2.
Did you find the recipe in Playing Curves HERE? Best,
Rok