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Drawing with Display.SimpleGraphics


#1

Ok - issue 2 - making the display work?

I’ve tried several variations of the program below - that one is from a message from Markdav about display colors - so he apparently had it working?

When the program runs - the display remains stubbornly blank.

I’m finding that AutoRedraw is set true already in ProgramStarted, but I don’t appear to get a redraw - even when I call Redraw().

Curiously - after drawing, if I hit reset, I see the display briefly (until the reboot clears it).


namespace DisplayTest1
{
    using System.Threading;

    using Microsoft.SPOT;

    using GT = Gadgeteer;

    public partial class Program
    {
        void ProgramStarted()
        {
            Debug.Print("enter ProgramStarted");
            if (display.SimpleGraphics.AutoRedraw)
            {
                Debug.Print("AutoRedraw true");
            }
            else
            {
                Debug.Print("AutoRedraw false");
            }

            Microsoft.SPOT.Font DispFont = Resources.GetFont(Resources.FontResources.small);

            int yloc;

            // Do one-time tasks here
            display.SimpleGraphics.Clear();
            display.SimpleGraphics.AutoRedraw = true;

            yloc = DispFont.Height;

            display.SimpleGraphics.DisplayText("Hello World - White", DispFont, GT.Color.White, 15, (uint)yloc); //ok
            yloc += (DispFont.Height);
            display.SimpleGraphics.DisplayText("Hello World - Red", DispFont, GT.Color.Red, 15, (uint)yloc); //ok
            yloc += (DispFont.Height);
            display.SimpleGraphics.DisplayText("Hello World - Green", DispFont, GT.Color.Green, 15, (uint)yloc); //no colour
            yloc += (DispFont.Height);

            Debug.Print("done DisplayText's");
            Thread.Sleep(5000);
            Debug.Print("done sleep - exit ProgramStarted");
        }
    }
}


#2

There is backlight on your display that turns on as soon as it is powered up. I sit on?

Do you see nay messages on screen while booting?


#3

Yes - the backlight does come on - the display does not appear to be defective in that way.
It also displays the boot messages. If I switch to serial (which is not connected), then the boot messages stay up.

As I mentioned in the message, if I hit reset after the drawing is done (when nothing is visible), then what was drawn DOES display until the boot cycle clears the screen (maybe 1/2 second?).

This appears to be more of a soft/firmware issue than hardware.

I have done several iterations of programs attempting to get a display and they all appear with the same results.
I’ve tried calling Redraw after each draw attempt, setting AutoRedraw (even though it’s apparently already true).
I’ve made sure to exit ProgramStarted, in case the Redraw doesn’t work until then.
I’m not using any event handlers on the display.


#4

“Curiouser and Curiouser” said Alice…

Ok - if I put all of the switches ON, then after reset, the boot messages come on, then a few seconds later, the screen flickers slightly, THEN my display messages are displayed!

Other switch positions and I get a blank display (I’ve tried 0000, 1000, 0111).

Is there some magic switch position I should be using during normal programming?


#5

This is very unusual! Pleaase email me your phone number and I will call you back

gusi@ “ghi domain name”.com