Render Speed on EMX with 7

I’m working on an gauge type indicator using the 7" LCD and the EMX/Cobra. It will have two pointers swinging from the top center of the display and deflecting +/- 60 degrees. Ideally I would like a refresh rate of 5-10Hz.

I’ve been trying to get an idea of performance for the system using the code below.

With the Glide Window set to 800x480 and the image object set to 560x280 it takes approx 17 seconds to render and flush the image to the screen 30 times. This is much improved over the 35+seconds my previous code was taking, that was repainting the entire 800x480 area.

My question is: Is this the expected performance for the EMX and the 7" display or am I doing something totally wrong?


using System.Threading;
using Microsoft.SPOT;
using GHIElectronics.NETMF.Glide;
using GHIElectronics.NETMF.Glide.Display;
using GHIElectronics.NETMF.Glide.UI;

namespace GlideTest1
    public class Program
        // This will hold the main window.
        static Window window;

        static long StartTick = 0;
        static long StopTick = 0;

        public static void Main()
            // Add the following as a txt file Resource named "WindowX"
            //  <Glide Version="1.0.4">
            //  <Window Name="window" Width="800" Height="480" BackColor="FFFFFF">
            //  <Image Name="image" X="120" Y="0" Width="560" Height="280" Alpha="255"/>
	        //  <Button Name="button" X="0" Y="0" Width="80" Height="32" Alpha="255" Text="Button" Font="4" FontColor="000000" DisabledFontColor="808080" TintColor="000000" TintAmount="0"/>
            //  </Window>
            //  </Glide>

            // Load the window, 
            window = GlideLoader.LoadWindow(Resources.GetString(Resources.StringResources.WindowX));

            // Initialize the image I will be drawing on
            Image image = (Image)window.GetChildByName("image");

            //Start timing
            StartTick = System.DateTime.Now.Ticks;

            Glide.MainWindow = window;

            for (int i=0; i < 30; i++)
                image.Bitmap.DrawEllipse(Colors.Blue, 20+i, 20+i, 50-i, 50-i);
                //also tried as a Rectangle to see if performance was impacted
                //image.Bitmap.DrawRectangle(Colors.Blue, 2, 20 + i, 20 + i, 50 - i, 50 - i, 0, 0, Colors.Red, 0, 0, Colors.Red,0,0,100);



                //Thread.Sleep(150);  //desired refresh rate is 5-10Hz

            //STOP TIMING
            StopTick = System.DateTime.Now.Ticks;

            //Print to debug how long the for loop operation took to complete.
            Debug.Print(((StopTick - StartTick) / 10000).ToString() + " mSec");

You can optimize here and there but graphics will need a lot processing power. Even 560x280 that seem small, it has 156800 pixels that need to be updated :slight_smile:

Would the Chipworkx have a sufficient performance gain to make it worth using?
and what if any modifications to the LCD or ChipWorkx dev board would be required to use the 7" LCD on the Chipworkx Dev Board?


ChipworkX is about 5 to 6 times faster than EMX

See this old post please

Thanks for the help. I’m off to do some modifications to my LCD