 import CoreGraphics
 
 public class LMUController {
-    var dataPort: io_connect_t = 0
+    private var dataPort: io_connect_t = 0
     
     private let kGetSensorReadingID: UInt32 = 0 // getSensorReading(int *, int *)
     private let kGetLEDBrightnessID: UInt32 = 1 // getLEDBrightness(int, int *)
     private let kSetLEDBrightnessID: UInt32 = 2 // setLEDBrightness(int, int, int *)
     private let kSetLEDFadeID: UInt32 = 3 // setLEDFade(int, int, int, int *)
     
+    /**
+    Initialize the connection to the LMU controller.
+    
+    :returns: Nil if it failed.
+    */
     public init?() {
         let serviceObject = IOServiceGetMatchingService(kIOMasterPortDefault, IOServiceMatching("AppleLMUController").takeUnretainedValue())
         

        return nil
    }
    
    public func setKeyboardBrightness(brightness: Float) -> Float? {
        let inputs = [UInt64(0), UInt64(brightness * 0xfff)]
        let outputs = callScalarMethod(kSetLEDBrightnessID, inputs: inputs)

    // TODO
    public var lightSensors: LightSensors? {
        get {
            let outputs = callScalarMethod(kGetSensorReadingID, inputs: [UInt64]())
            println(outputs)
            return LightSensors(left: 0, right: 0)
        }
    }
