Reading the iPhone's Ambient Light sensor

Question

I notice on my iPhone, after a few seconds of being in direct sun light, the screen will adjust to become brighter, dimmer etc. I was wondering if there was a way to interact with this sensor?

I have an application which is used outside. When you go into direct light, it becomes very difficult to see the screen for a few momments, before it adjusts. And even then, it's not always as bright as I'd like it to be. I would like to implement a high contrast skin for outdoor viewing, and a low contrast for indoor viewing.

Is this possible to read light sensor data, and if so, how do I extract these sensor values?

I would assume there is a light sensor however, as the camera knows when to use the flash.

Answer 1

On the other hand this is a different idea (maybe a silly one), using the brightness of the device's screen you can get some value of the external conditions.

From 0.12 (Dark) to 0.99 (Light)

The next line will get those values, give it a try, put some light on and off over the device to get different values.

NSLog(@"Screen Brightness: %f",[[UIScreen mainScreen] brightness]); 

Obviously Automatic Brightness feature should be turned on in order to get this to work.

Regards.