HeyKarlWakeUp.cs

using System;
using Android.App;
using Android.Content;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using Android.OS;
using Android.Hardware;

namespace HeyKarlWakeUp
{
    [Activity (Label = "HeyKarlWakeUp", MainLauncher = true)]
	public class MainActivity : Activity
	{
		Camera camera;
		Camera.Parameters cameraParameters;
		private bool isFlashOn = false;


		protected override void OnCreate (Bundle bundle)
		{
			base.OnCreate (bundle);

			// Set our view from the "main" layout resource
			SetContentView (Resource.Layout.Main);

			// Get our button from the layout resource,
			// and attach an event to it
			Button button = FindViewById<Button> (Resource.Id.myButton);
			
			button.Click += (sender, e) => PlayMarioPattern(delay => {

				Toggle(true);
				System.Threading.Thread.Sleep(100);
				Toggle(false);
				System.Threading.Thread.Sleep(delay);

			});

			try
			{
				camera = Camera.Open();
				cameraParameters = camera.GetParameters ();
				camera.StartPreview ();
			}
			catch (Exception ex)
			{
				Android.Util.Log.Debug ("CAM", ex.ToString());
				camera = null;
			}
		}

		protected override void OnStop ()
		{
			base.OnStop ();

			if (camera != null) {
				if (isFlashOn)
					Toggle (false);

				camera.StopPreview ();
				camera.Release();
			}
		}

		void Toggle(bool flashOn)
		{
			try
			{
				if (flashOn) 
				{
					var fm = Camera.Parameters.FlashModeTorch;

					cameraParameters = camera.GetParameters ();

					if (!cameraParameters.SupportedFlashModes.Contains (Camera.Parameters.FlashModeTorch))
						fm = Camera.Parameters.FlashModeOn;

					try
					{
						cameraParameters.FlashMode = fm;
						camera.SetParameters(cameraParameters);
					}
					catch (Exception ex)
					{
						Android.Util.Log.Debug ("CAM", ex.ToString());
					}

				} else {

					try
					{
						cameraParameters.FlashMode = Camera.Parameters.FlashModeOff;
						camera.SetParameters(cameraParameters);
					}
					catch (Exception ex)
					{
						Android.Util.Log.Debug ("CAM", ex.ToString());
					}

				}
			}
			catch (Exception ex)
			{
				Android.Util.Log.Debug ("CAM", ex.ToString());
			}
		}


		void PlayMarioPattern(Action<int> flash)
		{
			flash(75);
			flash(150);
			flash(150);
			flash(50);
			flash(150);
			flash(275);
			flash(287);
			flash(225);
			flash(200);
			flash(250);
			flash(150);
			flash(165);
			flash(75);
			flash(150);
			flash(100);
			flash(100);
			flash(75);
			flash(150);
			flash(75);
			flash(175);
			flash(150);
			flash(75);
			flash(75);
			flash(175);
			flash(275);
			flash(200);
			flash(250);
			flash(150);
			flash(165);
			flash(75);
			flash(150);
			flash(100);
			flash(100);
			flash(75);
			flash(150);
			flash(75);
			flash(175);
			flash(150);
			flash(75);
			flash(75);
			flash(250);
			flash(150);
			flash(50);
			flash(75);
			flash(75);
			flash(150);
			flash(150);
			flash(75);
			flash(75);
			flash(150);
			flash(75);
			flash(50);
			flash(110);
			flash(150);
			flash(50);
			flash(75);
			flash(75);
			flash(150);
			flash(150);
			flash(150);
			flash(75);
			flash(150);
			flash(150);
			flash(150);
			flash(50);
			flash(75);
			flash(75);
			flash(150);
			flash(150);
			flash(75);
			flash(75);
			flash(150);
			flash(75);
			flash(50);
			flash(110);
			flash(150);
			flash(50);
			flash(75);
			flash(75);
			flash(150);
			flash(150);
			flash(150);
			flash(75);
			flash(150);
			flash(150);
			flash(150);
			flash(50);
			flash(75);
			flash(75);
			flash(150);
			flash(150);
			flash(75);
			flash(75);
			flash(1000);
			flash(200);
			flash(200);
			flash(200);
			flash(200);
			flash(2000);
		}
	}
}