Oscilloscope - few problems and limitations

This is example of TVOut lib with a bit changed schematic involving 75Ohm resistor and 300Ohm (instead 470) in order to get 0, 0.3 and 1V approx...

Otherwise with original set of resistors (1K and 470Ohm), oscilloscope in simulator shows even peaks of 5V...

However, what here is the problem is setting ranges manually. For instance, if enter 0, it switch to pV, then it is not possible do anything with knobs to reach sensible voltage.

Also hold button missing, instead to pause simulator. But until ro be able to do that, too much time passed and then is difficult to return back..

Thus:
- (Auto)HOLD button may be quite useful
- In AUTO mode, peak to peak constant display in given time period would be useful. Now fast drifts exists between 0.3 and 1V, which is quite unpleasant since time period is way too short
- More user friendly navigation (zoom in/out), double click to set position
- Measuring time and voltage difference between 2 points, similar as implemented in many oscilloscopes, would be very useful.
- Ability to save data for each band for further analyze

I believe that is minimum for a bit more comfortable usage.

Using knobs here are quite slow, thus using standard behavior with mouse is much easier and faster.

The second interesting example I have made is this:

"How to measure a capacitor with an oscilloscope.", by mjlorton
https://www.youtube.com/watch?v=VylC8JFoiBo

Here is necessary to have these diff. measurements I have mentioned. Anyway, very useful feature.

However, what here is the problem is setting ranges manually. For instance, if enter 0, it switch to pV, then it is not possible do anything with knobs to reach sensible voltage.

You can set another value, for example 1000000 pV.
Or if you click on "Auto" for that channel it will scale to fit the track (peak to peak).

- In AUTO mode, peak to peak constant display in given time period would be useful. Now fast drifts exists between 0.3 and 1V,

There is a "Filter" property: oscilloscope will ignore voltage changes below that value.
You can set "Auto" to scale the wave and then deactivate it and fine tune by hand.

- More user friendly navigation (zoom in/out), double click to set position

In Logic Analizer you can grab and move the "wave" with the mouse.
Now this is also implemented in Oscilloscope (Rev 1146).

In adition, now Mouse wheel will zoom in/out Time in both Oscilloscope and Logic Analizer (Rev 1145).

- Measuring time and voltage difference between 2 points, similar as implemented in many oscilloscopes, would be very useful.

Voltage at mouse pointer position is already shown.
Voltage differential is not yet implemented.

Time was already shown (respect to center).
In Logic Analizer you can set "time 0" with mouse middle button (will be used for voltage 0 as well).
Now this is also implemented in Oscilloscope (Rev 1146).


Some other features are planned, specially for trigger: Level, Slope, Holdoff time.
Also saving data is planned.

The second interesting example I have made is this:

"How to measure a capacitor with an oscilloscope.", by mjlorton
https://www.youtube.com/watch?v=VylC8JFoiBo

Here is necessary to have these diff. measurements I have mentioned. Anyway, very useful feature.

You can do this (much easier than in the video).
If you want more precision you need to reduce the simulation step.
In this case with 10 ns simulation step is Ok, measured capacity 46.99 nF:

Thank you very much. These changes makes all much easier,,,

One problem I have mentioned is zoom in. When do that its basic point is left corner, what is much more useful is to zoom in at point where mouse the pointer is.

Another problem for me personally (problem with vision even at 32" TV) are very small fonts for voltage and time. I need to move on less than 1m or so to see them, otherwise I do not see anything expect unclear shapes of numbers. It would be very useful for me to show it somewhere in else, on the bottom or right panel, with larger fonts...

In general, default fonts are very small for me. Perhaps to have settings for each panel and/or easier to to enlarge it automatically on Ctrl+,,,

One problem I have mentioned is zoom in. When do that its basic point is left corner, what is much more useful is to zoom in at point where mouse the pointer is.

That is not really possible, at least not if a trigger is selected.

Another problem for me personally (problem with vision even at 32" TV) are very small fonts for voltage and time. I need to move on less than 1m or so to see them, otherwise I do not see anything expect unclear shapes of numbers. It would be very useful for me to show it somewhere in else, on the bottom or right panel, with larger fonts...

That probably will come with next redesign: adding trigger options and an info panel.

In general, default fonts are very small for me. Perhaps to have settings for each panel and/or easier to to enlarge it automatically on Ctrl+,,,

You can configure font scale: settings->App->Font Scale.

Font scale is global setting, which is not quite convenience. No need to see enlarged icons and text there, in main display, debug info etc, if not required.

BTW, there is an error in scope font display when is scale is set to 1.5 - they are cut in half (linux).

Perhaps also to change color of the font and the place of display? Yellow and white are just the same as the wave color and if the wave length is quite short but with high frequency, values cannot be recognized...

Font scale is global setting, which is not quite convenience. No need to see enlarged icons and text there, in main display, debug info etc, if not required.

No, you should set font scale to see all the texts at a confortable size.

Font size of voltages and time inside the dispaly must be small to not interfere too much.
If you set an apropiate scale for the App, voltage and time is small but still perfectly visible.

Perhaps also to change color of the font and the place of display? Yellow and white are just the same as the wave color and if the wave length is quite short but with high frequency, values cannot be recognized...

Colors are needed to identify channels.
One option would be to put voltages and time in a line at the bottom of the display.
But this has a disadvantage: when you are placing the cursor you can't look at the bottom at the same time.
Perhaps we can have both:
- Values at the cursor that refresh continuously.
- Values at the bottom that refresh when you click and keep that value until you click again.

BTW, there is an error in scope font display when is scale is set to 1.5 - they are cut in half (linux).

You are right, I will fix it.

One problem I have mentioned is zoom in. When do that its basic point is left corner, what is much more useful is to zoom in at point where mouse the pointer is.

Finally I implementyed it, but it's disabled if Oscilloscope has a trigger (Rev 1151).

Stilll messes up the timings, but not a big problem.
Doing it manually is the same.

Now all is much more easier. Thanks.

BTW, there is an error in scope font display when is scale is set to 1.5 - they are cut in half (linux).

Solved at Rev 1153.

Can you add also time difference measurement by mouse? It is not quite simple to precisely set desire signal at center of the screen (zero) and then end of the wave may be out of view, in order to see precise spot.

Setting left and right cursor can be done by simply selecting measurement and moving vertical lines (blue, red, whatever). That way can zoom in as far is necessary to set each line on the spot.

Can you add also time difference measurement by mouse?

You can set "time 0" with middle button, then that is the new time reference (not the center).
If you do it close to the center it will auto-align to the center.

Yes, however, that is not quite practical. Especially auto-align in center. Classical measurement is stable solution. Also these problems with value font and its color already mentioned...

Perhaps for some future revision...