Integral Design

Here’s an example that graphically displays data from the Seeed Gyro module for .NET Gadgeteer.  The GHI Electronics Display_T35 module displays the output.

Plug the Gyro module into Socket 3.  Connect the display module and a button in the .NET Gadgeteer designer, but do not connect the optional touch-screen cable to Socket 10.  Apparently the touch screen is incompatible with the Seeed Gyro and Accelerometer modules.  (This example is easily adaptable to the Accelerometer, and I found it instructive to try both modules in this application.)

The following code block is the complete Program.cs file.  It sets a measurement interval for the Gyro module at 100 ms.  When the program starts, it calibrates the Gyro to the position it occupies at startup.  Make sure it is not moving during calibration.  A delegate is assigned to handle the MeasurementComplete event.  Everything of interest happens in the MeasurementComplete handler.  A button starts and stops the measurements by calling the methods StartContinuousMeasurements and StopContinuousMeasurements on the Gyro.

using Microsoft.SPOT;

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

namespace Gyro
{
    public partial class Program
    {

        void ProgramStarted()
        {
            gyro.ContinuousMeasurementInterval = new System.TimeSpan(0, 0, 0, 0, 100);
            gyro.Calibrate();

            gyro.MeasurementComplete +=
                new GTM.Seeed.Gyro.MeasurementCompleteEventHandler(gyro_MeasurementComplete);

            button.ButtonPressed += new Button.ButtonEventHandler(button_ButtonPressed);

            Debug.Print("Program Started");
        }

        void button_ButtonPressed(Button sender, Button.ButtonState state)
        {
            if (button.IsLedOn)
            {
                gyro.StopContinuousMeasurements();
                button.TurnLEDOff();
            }
            else
            {
                gyro.StartContinuousMeasurements();
                button.TurnLEDOn();
            }
        }

        void gyro_MeasurementComplete(GTM.Seeed.Gyro sender, GTM.Seeed.Gyro.SensorData sensorData)
        {
            display.SimpleGraphics.Clear();
            if (sensorData.X > 0 && sensorData.Y > 0)
            {
                display.SimpleGraphics.DisplayEllipse(Gadgeteer.Color.Orange, 150, 125, (uint)(sensorData.X * 10), (uint)(sensorData.Y * 10));
            }
            else
            {
                display.SimpleGraphics.DisplayText("Gyro sensor X: " + sensorData.X.ToString(),
                    Resources.GetFont(Resources.FontResources.NinaB), GT.Color.Purple, 25, 75);
                    display.SimpleGraphics.DisplayText("Gyro sensor Y: " + sensorData.Y.ToString(),
                    Resources.GetFont(Resources.FontResources.NinaB), GT.Color.Purple, 25, 100);
            }
        }
    }
}

The code in the gyro_MeasurementComplete handler draws an ellipse on the Display_T35 when there is rotation in a positive direction along the X and Y axes.  The horizontal radius of the ellipse corresponds to the rotation on the X axis of the Gyro and the vertical radius corresponds to the rotation on the Y axis.  It isn’t possible to draw an ellipse with a negative radius when rotation is negative on either axis, so the code simply prints the data to the screen.

I found a little experimentation with this data display to be helpful in understanding how the Gyro works.