Pascal Hibon wrote: 
> I'm curious about the differences; could you post a picture of the old
> and new display's hardware?
> 
> The brightness value is stored in
> /sys/class/backlight/rpi_backlight/brightness. I currently write the
> brightness value at boot time into this file. After some more
> experimenting I find a value of 50 a good value for the brightness. 
> I suppose your applet could also write the brightness value at boot time
> (?). You just need to have the proper user privileges to write to the
> brightness file. And your applet should also find a way to determine
> what hardware version of the display is installed and only allow
> brightness adjustments on the "new" hardware version. I don't know if
> that will be possible.

Hi Pascal,

I won't be able to take pictures of the old one as this requires a
complete disassembly of my player. The new one had a revision 1.1 if I
recall correctly. I can take pictures of this one but this will have to
wait a few days.

The official Raspberry forums mentioned a brightness setting for the
"old" display some time ago (about the same time the backlight on/off
function was introduced). But suddenly this option was removed with no
real official explanation. I can only presume some hardware issue was
discovered with the original PCB/display.

Writing the brightness value at boot time is not the challenge. Storing
the user defined brightness value needs some more thought though.
Rebooting the Pi restores the brightness value to 255, so there has to
be a way to store and recall this setting as piCore runs from RAM. In my
opinion there is no need to determine the hardware revision (if this is
even possible) as people with the old display have no need for an applet
provided brightness setting.

Regards,

Arie


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