Re: LED backlight control?

FROM : Michael Vannorsdel
DATE : Thu May 01 23:16:12 2008

Checkout this code sample:

http://osxbook.com/book/bonus/chapter10/light

it shows setting the display brightness and dealing with the ambient 
light sensor on portables using IOKit.


On May 1, 2008, at 3:05 PM, Rick Mann wrote:

> Hi. I was posting questions on Carbon Dev, but this is probably more 
> appropriate.
>
> I'm interested in developing a utility that allows the user to dim 
> the screen and change the output to red, for very dark area use 
> (i.e. astronomy). I've figured out how to use 
> CGSetDisplayTransferByFormula() to make the screen red, and I can 
> even make it fairly dark, but it's still far too bright.
>
> While CCFL backlights can only dim so far, LED backlights can 
> theoretically dim all the way to "off." However, the standard 
> backlight controls don't go anywhere near "off" before turning the 
> backlight all the way off.
>
> Is there any way (perhaps even low-level communications with the 
> hardware, such as I've seen to get the light sensor and 
> accelerometer readings) to programmatically set the backlight level 
> very low?