Gadgeteer_DD02_Oled_GPS_01

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.Touch;

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

namespace Gadgeteer_DD02_Oled_GPS_01
{
    public partial class Program
    {
        // create a program wide variable switch
        // has the gps worked out the position yet?
        bool postionCalculated = false;

        // create a font that we can use on the oled display screen
        Font displayFont = Resources.GetFont(Resources.FontResources.NinaB);

        // This method is run when the mainboard is powered up or reset.
        void ProgramStarted()
        {
            /*******************************************************************************************
            Modules added in the Program.gadgeteer designer view are used by typing
            their name followed by a period, e.g.  button.  or  camera.

            Many modules generate useful events. Type +=<tab><tab> to add a handler to an event, e.g.:
                button.ButtonPressed +=<tab><tab>

            If you want to do something periodically, use a GT.Timer and handle its Tick event, e.g.:
                GT.Timer timer = new GT.Timer(1000); // every second (1000ms)
                timer.Tick +=<tab><tab>
                timer.Start();
            *******************************************************************************************/

            // create a gps new postion recieved event handling robot
            gps.PositionReceived += new GPS.PositionReceivedHandler(gps_PositionReceived);

            // create a gps new NMEA signal recieved event handling robot
            gps.NMEASentenceReceived += new GPS.NMEASentenceReceivedHandler(gps_NMEASentenceReceived);

            // stop the oled display redrawing every time we add a graphic element to the screen memory
            oledDisplay.SimpleGraphics.AutoRedraw = false;

            // Use Debug.Print to show messages in Visual Studio's "Output" window during debugging.
            Debug.Print("Program Started");
        }

        void gps_NMEASentenceReceived(GPS sender, string nmeaSentence)
        {
            // the gps has recieved another message from a satellite! (or maybe it is a nearby ship?)

            // have we calculated the postion yet?
            // if we have then stop printing the NMEA messages
            if (postionCalculated == false)
            {
                // print the NMEA message just for fun
                Debug.Print(nmeaSentence);

                // jump out of the event handler to free it up
                // print the message to the oled display
                processNMEAMessage(nmeaSentence);
            }

        }

        void gps_PositionReceived(GPS sender, GPS.Position position)
        {
            // the gps has recieved enough information and the first position has been calculated!
            Debug.Print(position);

            // flick the switch to note that the position has now been calculated and to stop showing NMEA messages
            postionCalculated = true;

            // jump out of the event handler to free it up
            // send the message to be processed and sent to the oled display screen
            processGPSMessage(position);
        }

        void processNMEAMessage(string recievedMessage)
        {
            // clear the oled display screen memory of graphics
            oledDisplay.SimpleGraphics.Clear();

            // write the message to the display screen
            printOledDisplay(1, recievedMessage);

            // write part of the message to the the next line on the screen?
            // careful as it will crash if the message is shorter than you think
            //printOledDisplay(2, recievedMessage.Substring(15, 15));

            // redraw the screen with all new graphics
            oledDisplay.SimpleGraphics.Redraw();

        }

        void processGPSMessage(string recievedMessage)
        {
            // clear the oled display screen memory of graphics
            oledDisplay.SimpleGraphics.Clear();

            // write the message to the display screen
            // cut out the first part of the message
            // Indexof give the position of a word and Substring gives the letters between two numbers from a text string
            printOledDisplay(1, recievedMessage.Substring(0, recievedMessage.IndexOf("Long ")));
            // cut out the second part of the message
            printOledDisplay(2, recievedMessage.Substring(recievedMessage.IndexOf("Long "), recievedMessage.IndexOf("Speed ") - recievedMessage.IndexOf("Long ")));
            // cut out the third part of the message
            printOledDisplay(3, recievedMessage.Substring(recievedMessage.IndexOf("Speed "), recievedMessage.IndexOf("Course ") - recievedMessage.IndexOf("Speed ")));
            // leave out the forth part of the message
            // cut out the ast part if the fifth part of the message
            printOledDisplay(4, recievedMessage.Substring(recievedMessage.IndexOf("2013 ") + 5));

            // redraw the screen with all new graphics
            oledDisplay.SimpleGraphics.Redraw();

        }

        // a custom method for printing text to the OLED screen
        // input a line number and the text to be printed as a text string
        void printOledDisplay(uint lineNumber, string displayMessage)
        {
            uint xPos = 0;
            oledDisplay.SimpleGraphics.DisplayText(displayMessage, displayFont, GT.Color.White, xPos, lineNumber * 12);
        }


    }
}