Gray experiment utility

[Drakker]

Source and HEX available here: http://drakker.org/gamebuino/gray_experiment/

This utility is a test of multiple ways to display gray. You can select the type of gray using the left and right buttons and adjust the FPS with the up and down buttons.

Findings so far:

- Gray displays differently from screen to screen (already known).

- Gray is pretty much a crap shoot (already known).

- FPS doesn't seem to matter much, depending on the display. Some combinations of screens and gray types work just fine at 15fps.

- Some patterns of gray have an impact on the whole display, on all my screens the horizontal striped gray made the text at the bottom of the screen gray too, while it is not.

- Checkered gray seems to work the best on all 3 of my displays.

- More to come later...

I would like to get some feedback, if you guys can try it out and report on what type of gray works best/worst on your display and at what FPS, maybe we can figure out a gray pattern that is usable.

[quosa]

Well DONE! After testing with your utility - decision is done: checkersmall1

[Drakker]

Great, thanks for trying it and reporting your findings. Seems like checkered is the way to go for gray. Did you get the blinking text at the bottom with the horizontal striped gray?

[Sushi]

No, did you? I've replaced my display three times, and I'm using the best one I've come across, so maybe it's your display if you're getting flashing.

[erico]

I should be giving this a go a bit after 20th now...interesting proposal!

[Drakker]

I got the text flickering with the horizontal striped pattern on all 3 of my displays, but one of them is ghosting so badly that nothing looks right on it anyway.

[erico]

checkered above 26-27 seems to produce ok results here with an ocasional stripe going around at a slow speed.
No blinking texts whatsoever.

the filled type seems to be even able to produce different types of lighter grays but they have a bigger stripe going vertically.
Somehow it seems that a value in between 20-22 or 40-42 could stabilize such.
is there a way to use something like 41.5? or increase it by .25?

[Drakker]

For that I'd have to check the code for the Gamebuino library, all the examples from Rodot use integers, but by modifying the library, it is probably possible to use milliseconds per frame instead of frames per second. I'll check that out in the next few days.

[erico]

Nice. It kind of reminds me of recording video images back in the days. Things needed a precision sync that was sure very "float point" not to band. Maybe we have a similar situation? Is the exact refresh rate of gamebuinos screen at 20? Or is it something like 19.98?

[Drakker]

According to Myndale it is roughly 41 fps.