Integral Design

This device is implemented using the modules and mainboard that ship with the GHI Electronics Spider Kit for Micorosoft .NET Gadgeteer.  It uses the GHI Electronics .NET Gadgeteer Display T35 Module touch screen to activate the camera and to display bitmaps captured by the camera.  The device is powered by the USB Client DP Module (UsbClientDP) connected to the USB port of the development computer.  The DP Module also provides a conduit to load assemblies to the mainboard.

After the device boots, a touch to the display screen activates the camera, which starts streaming bitmaps.  The display module shows each frame as it is captured.  A second touch to the screen stops the camera and provides the option to save the last frame to storage on an SD card Module for .NET Gadgeteer socket type F.

A LED module turns red when the camera is streaming bitmaps and green when streaming stops.  After several bitmaps have been captured and saved to the SD Card storage, pushing the button module starts display of all the bitmaps that have been stored on the SD card.

The following illustration shows the device in the Microsoft Visual Studio .NET Gadgeteer Designer.

Touch Screen Camera SDCard in .NET Gadgeteer Designer

The following code runs the Camera, Touch Screen, SD Card example.  Saving the image to storage depends on a utility function that is exclusive to the GHI Spider Kit for .NET Gadgeteer.  (See the comments for more information on the util library that contains this function.)

using System;
using Microsoft.SPOT;
using Microsoft.SPOT.Presentation;
using Microsoft.SPOT.Presentation.Controls;
using Microsoft.SPOT.Presentation.Media;

using System.Collections;
using System.IO;

using GT = Gadgeteer;
using GTM = Gadgeteer.Modules;
using Gadgeteer.Modules.GHIElectronics;
using GHIElectronics.NETMF.System;

namespace SDCardCameraTouchScreen
{
    public partial class Program
    {
        Window mainWindow;
        StackPanel stackPanel;
        Bitmap currentBitmapData;

        Image saveImage = new Image(Resources.GetBitmap(Resources.BitmapResources.SaveImg));
        Image skipImage = new Image(Resources.GetBitmap(Resources.BitmapResources.SkipImg));
        ArrayList buttons = new ArrayList();

        uint imageNumber = 0;

        void ProgramStarted()
        {
            // Do one-time tasks here
            button.ButtonPressed += new Button.ButtonEventHandler(button_ButtonPressed);
            camera.BitmapStreamed += new Camera.BitmapStreamedEventHandler(camera_BitmapStreamed);
            SetupDisplay();
            led.TurnGreen();

            Debug.Print("Program Started");

            display.SimpleGraphics.DisplayTextInRectangle(
                "Touch screen to start streaming bitmaps. Touch again to stop and save picture.",
                50, 50, 250, 200, GT.Color.Green, Resources.GetFont(Resources.FontResources.NinaB),
                GTM.Module.DisplayModule.SimpleGraphicsInterface.TextAlign.Left,
                GTM.Module.DisplayModule.SimpleGraphicsInterface.WordWrap.Wrap,
                GTM.Module.DisplayModule.SimpleGraphicsInterface.Trimming.WordEllipsis,
                GTM.Module.DisplayModule.SimpleGraphicsInterface.ScaleText.ScaleToFit);

            System.Threading.Thread.Sleep(4000);
        }

        void SetupDisplay()
        {
            mainWindow = display.WPFWindow;
            stackPanel = new StackPanel(Orientation.Horizontal);
            stackPanel.HorizontalAlignment = HorizontalAlignment.Center;
            stackPanel.SetMargin(4);
            stackPanel.Children.Add(saveImage);
            stackPanel.Children.Add(skipImage);

            buttons.Add(saveImage);
            buttons.Add(skipImage);
            foreach (Image button in buttons)
                button.Visibility = Visibility.Hidden;

            mainWindow.Child = stackPanel;

            mainWindow.TouchDown += new Microsoft.SPOT.Input.TouchEventHandler(mainWindow_TouchDown);

        }

        void ShowButtons()
        {
             foreach (Image button in buttons)
                button.Visibility = Visibility.Visible;

            saveImage.TouchDown += new Microsoft.SPOT.Input.TouchEventHandler(saveImage_TouchDown);
            skipImage.TouchDown += new Microsoft.SPOT.Input.TouchEventHandler(skipImage_TouchDown);

            mainWindow.Invalidate();
        }

        void HideButtons()
        {
            foreach (Image button in buttons)
            {
                button.Visibility = Visibility.Hidden;
            }

            skipImage.TouchDown -= new Microsoft.SPOT.Input.TouchEventHandler(skipImage_TouchDown);
            saveImage.TouchDown -= new Microsoft.SPOT.Input.TouchEventHandler(saveImage_TouchDown);

            mainWindow.Invalidate();
        }

        void skipImage_TouchDown(object sender, Microsoft.SPOT.Input.TouchEventArgs e)
        {
            HideButtons();
        }

        void saveImage_TouchDown(object sender, Microsoft.SPOT.Input.TouchEventArgs e)
        {
            if (VerifySDCard())
            {
                GT.StorageDevice storage = sdCard.GetStorageDevice();
                imageNumber = (uint)storage.ListFiles("\\SD\\").Length;

                byte[] bytes = new byte[currentBitmapData.Width *
                                                    currentBitmapData.Height * 3 + 54];
                Util.BitmapToBMPFile(currentBitmapData.GetBitmap(), currentBitmapData.Width,
                                                                  currentBitmapData.Height, bytes);
                GT.Picture picture = new GT.Picture(bytes, GT.Picture.PictureEncoding.BMP);

                string pathFileName = "\\SD\\Image-" + (imageNumber++).ToString() + ".bmp";

                try
                {
                    storage.WriteFile(pathFileName, picture.PictureData);
                }
                catch (Exception ex)
                {
                    Debug.Print("Message: " + ex.Message + "  Inner Exception: " + ex.InnerException);
                }
            }

            HideButtons();
        }

        void mainWindow_TouchDown(object sender, Microsoft.SPOT.Input.TouchEventArgs e)
        {
            if (saveImage.Visibility == Microsoft.SPOT.Presentation.Visibility.Visible)
                return;

            if (saveImage.Visibility == Microsoft.SPOT.Presentation.Visibility.Hidden &&
                                                           led.GetCurrentColor() == GT.Color.Red)
            {
                ShowButtons();
                camera.StopStreamingBitmaps();
                led.TurnGreen();
            }
            if (saveImage.Visibility == Microsoft.SPOT.Presentation.Visibility.Hidden &&
                                                           led.GetCurrentColor() == GT.Color.Green)
            {
                HideButtons();
                camera.StartStreamingBitmaps(new Bitmap(camera.CurrentPictureResolution.Width,
                                                          camera.CurrentPictureResolution.Height));
                led.TurnRed();
            }
        }

        void camera_BitmapStreamed(Camera sender, Bitmap bitmap)
        {
            display.SimpleGraphics.DisplayImage(bitmap, 0, 0);
            currentBitmapData = bitmap;
        }

        void button_ButtonPressed(Button sender, Button.ButtonState state)
        {
            button.TurnLEDOn();

            if (VerifySDCard())
            {
                GT.StorageDevice storage = sdCard.GetStorageDevice();

                foreach (string s in storage.ListRootDirectorySubdirectories())
                {
                    Debug.Print(s);
                    if (s == "SD")
                    {
                    foreach (string f in storage.ListFiles("\\SD\\"))
                        {
                            Bitmap bitmap = storage.LoadBitmap(f, Bitmap.BitmapImageType.Bmp);
                            display.SimpleGraphics.DisplayImage(bitmap, 0, 0);
                            System.Threading.Thread.Sleep(2000);
                        }
                    }
                }
            }

            button.TurnLEDOff();
        }

        bool VerifySDCard()
        {
            if (!sdCard.IsCardInserted || !sdCard.IsCardMounted)
            {
                display.SimpleGraphics.DisplayText("Insert SD card!",
                        Resources.GetFont(Resources.FontResources.NinaB), GT.Color.Cyan, 20, 50);

                System.Threading.Thread.Sleep(2000);
                display.SimpleGraphics.ClearNoRedraw();

                led.BlinkRepeatedly(GT.Color.Orange);
                return false;
            }

            return true;
        }
    }
}