Fabio's *%

Change backlight brightness on iPhone

1. Get the current backlight value stored in Settings

    NSNumber *bl = (NSNumber*) CFPreferencesCopyAppValue(CFSTR("SBBacklightLevel"), CFSTR("com.apple.springboard"));
   prevBacklightLevel = [bl floatValue];

2. Set our new value

   GSEventSetBacklightLevel(1.0f); // from 0.0 (off) to 1.0 (max)

3. Then restore the previous brightness

   - (void)applicationWillTerminate
   {
   	GSEventSetBacklightLevel(prevBacklightLevel);
   }