CrystalControl2 <-> Contrast 633


New member
By clicking with the LMB on the CC2 icon in the taskbar, it gives the option to adjust brightness and contrast on the fly.
This works fine for the brightness, just pull the slider from left to right and the brightness adjusts itself from 0 -> 100%.
However, the contrast stays the same from 100%->20%, no any adjustment at all, beneath 20% the screen turns all the way black and will not go back to normal anymore until I use the 'configure' option and restart the service. One would think that close to 100% the contrast would be black, but now it's on the left side of the slider that it turns black.

When I run Wintest, the contrast can be set MUCH better then with CC2. At the moment I have to sit right in front of the panel to see something, with Wintest the viewing angle is almost 180' instead.
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Last edited:

CF Mark

Well thats a very strange problem.
CC2 doesnt do anything weird with the brightness or contrast values... they are sent out to the LCD in exactly the same way as Wintest does it.

The optimum contrast setting area is quite narrow though.
From memory a good setting for the 633 is around 27%.
5% each way from that value can make a big difference.


New member
With Wintest:
- 0% contrast is 'blank'
- 100% contrast is 'black'

With CC2:
- 0% contrast is 'blank'
- 12->19% contrast is 'black'
- 20->100% contrast is 'very dim' (the bootscreen contrast)

When clicked on the trayicon, the behaviour is the same, except that after (roundabout, since there are no percentages)12% the contrast is 'black' and stays 'black until 100%

At the moment I have set contrast at 8% which greatly improved visibility at bigger view angles, but still doesn't show a dark background pixels.
Brightness is in my opinion a personal preference and doesn't really influence the viewing angle. Brightness reacts the same in both Wintest and CC2

(running CC2 20060325 / 156)

CF Tech

633_WinTest changes the contrast a bit before it sends it to the display--the slide is 0 to 100, but the module only accepts 0-50.

Open up the packet degugger, un-check "ASCII" and then send some contrast commands with the silder and watch what 633_WinTest really sends to the module.

CF Mark

Sorry, you are correct, this is a bug.

CC2 is sending 0->255 values of contrast to the 633 when it should be 0->50.

A fixed version of the 633 plugin is attached.
Stop CC2 and then copy this new plugin into your CrystalControl2 directory overwriting the old file.



New member
This fixed it alltogether! :)

Thanks for looking into this problem. I know the problem sounded kind of weird :eek: