Main Site Documentation

Cobra II and N7 display issues


#1

Just got my first Gadgeteer mainboard and decided to hook it up to the N7 to try out any sample code. Problem is that the signal seems to be out of sync and the screen flickers. See pictures.

One is of the board booting up. The other is an attempt to draw a filled in rectangle.

using System;
using System.Collections;
using System.Threading;
using Microsoft.SPOT;
using Microsoft.SPOT.Presentation;
using Microsoft.SPOT.Presentation.Controls;
using Microsoft.SPOT.Presentation.Media;
using Microsoft.SPOT.Presentation.Shapes;
using Microsoft.SPOT.Touch;
using GHI.Hardware.G120;
using GHI.Premium.Hardware;
using GHI.Premium.Hardware.LowLevel;


using Gadgeteer.Networking;
using GT = Gadgeteer;
using GTM = Gadgeteer.Modules;
using Gadgeteer.Modules.GHIElectronics;

namespace GadgeteerApp1
{
    public partial class Program
    {
        // This method is run when the mainboard is powered up or reset.   
        void ProgramStarted()
        {
           
            GTM.GHIElectronics.Display_N7 N7 = new GTM.GHIElectronics.Display_N7(3,2,1);


            N7.SimpleGraphics.DisplayRectangle(GT.Color.Magenta, 4, GT.Color.Purple, 10, 10, 400, 200);

        }
    }
}

This is my current source(Not initializing in the designer code in this iteration). Prior to this I have also tried the default display_N7 object creation through Designer and also using an Configuration.LCD.Configurations object at program start to try and configure display per CP7 “non-gadgeteer” example.

I haven’t been able to find much on this issue. Only a pixel clock divider flickering issue that I’ve found while browsing Hydra dev guide, which I’m not sure how to attempt.

Am I missing something?


#2

Welcome to the forum. It can be power related. Have you tried powered USB hub?


#3

I have tried the desktop tower’s USB, a powered USB hub, and an external 9V 650mA power adapter.


#4

Also try adding the driver through the designer.


#5

And welcome to the community :slight_smile:


#6

There is a problem in the current driver where the pixel clock rate is set improperly on some devices, Cobra II being one of them. This will be fixed in the coming SDK, but if you want to do the following, it can fix it now.

Follow the instructions on this page: https://www.ghielectronics.com/docs/122/gadgeteer-driver-modification to add and reference the Display N7 source to your project. Change line 110 “lcdConfig.PixelClockDivider = 3;” to read “lcdConfig.PixelClockDivider = 5;” and redeploy. The problem should be fixed.