windows mobile gps 串口通信 NMEA命令和数据处理(1) (c#)

这几天在搞wm上面的gps 想获取到卫星数据 找了些资料

大概的就是这两种方式：一，传统的gps编程方式 通过串口读取到gps设备的数据，解析，处理

二，应用windows mobile 提供的gpsid函数库

下面试 gps传统编程

1 串口通信，首先打开gps设备的port并接收数据

命名空间

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
using System.IO.Ports;

using GPS;//这个是gps设备的类，下面将有介绍

 

public NMEAProtocol protocol = new NMEAProtocol();
        public SerialPort port = new SerialPort();

  System.Text.Encoding encoding = System.Text.ASCIIEncoding.GetEncoding(1252);

连接的事件

private void connectButton_Click(object sender, System.EventArgs e)
  {
   connectButton.Enabled = false;
   disconnectButton.Enabled = true;
            COMlistBox.Enabled = false;
            port.PortName = COMlistBox.SelectedItem as string;
            port.Parity = Parity.None;
            port.BaudRate = 4800;
            port.StopBits = StopBits.One;
            port.DataBits = 8;
            port.Open();
   timer1.Enabled = true;
  }

 

//timer控件事件

private void timer1_Tick(object sender, System.EventArgs e)
  {
   ReadData();
  }

//读取数据
  private void ReadData()
  {
   byte[] bData = new byte[256];

   try
   {
    //bData = serialHelper.Read();
                port.Read(bData, 0, 256);

    protocol.ParseBuffer(bData);
   }
   catch(Exception e)
   {
                System.Diagnostics.Debug.WriteLine(e.ToString());
    //swallow it.
   }

//显示数据

   DisplayNMEARawData(bData);
   DisplayGeneralInfo();
   DisplaySatellites();
  }

  private void DisplayNMEARawData(byte[] bData)
  {
   string sData="";
   if(null != bData)
   {
    sData = encoding.GetString(bData);
   }

   if (dumpRawDataCheck.Checked)
   {
    //if dumped 100k of data get rid of the oldest 50k
    if(NMEAText.Text.Length > 100*1000)
    {
     NMEAText.Text = NMEAText.Text.Substring(50000,50000);

    }

    NMEAText.Text =    NMEAText.Text + sData;
    NMEAText.SelectionStart = NMEAText.Text.Length-1;
    NMEAText.ScrollToCaret();
   }
  }

  private void DisplayGeneralInfo()
  {
   labelLatitude.Text = protocol.GPGGA.Latitude.ToString();
   labelLongitude.Text = protocol.GPGGA.Longitude.ToString();
   labelAltitude.Text = protocol.GPGGA.Altitude.ToString();

            DateTime utc = DateTime.MinValue;  

            if (protocol.GPRMC.Month != 0 && protocol.GPRMC.Year != 0 && protocol.GPRMC.Day != 0)
            {
                utc = new DateTime(protocol.GPRMC.Year + 2000, protocol.GPRMC.Month, protocol.GPRMC.Day, protocol.GPGGA.Hour, protocol.GPGGA.Minute, protocol.GPGGA.Second, DateTimeKind.Utc);
                labelDate.Text = utc.ToShortDateString();
                labelTimeLocal.Text = utc.ToLocalTime().ToString();
                labelTime.Text = utc.ToShortTimeString();
            }

   listGPSQuality.SelectedIndex = (int)protocol.GPGGA.GPSQuality;

            labelFixMode.Text = protocol.GPGSA.Mode == 'A' ? "Automatic" : "Manual";
            labelPDOP.Text = protocol.GPGSA.PDOP.ToString();
            labelVDOP.Text = protocol.GPGSA.VDOP.ToString();
            labelHDOP.Text = protocol.GPGSA.HDOP.ToString();

            labelDataValid.Text = protocol.GPRMC.DataValid == 'A' ? "Data Valid" : "Navigation Receive Warning";

  }

  private void DisplaySatellites()
  {
   labelSatellitesInView.Text =  protocol.GPGSV.SatellitesInView.ToString();
   
            Pen circlePen = new Pen(System.Drawing.Color.DarkBlue,1);

   Graphics g= picSats.CreateGraphics();
  
   int centerX = picSats.Width/2;
   int centerY = picSats.Height/2;

   double maxRadius = (Math.Min(picSats.Height,picSats.Width)-20) / 2;

   //draw circles
   double[] elevations = new double[] {0,Math.PI/2, Math.PI/3 ,Math.PI / 6};

   foreach(double elevation in elevations)
   {
    double radius = (double)System.Math.Cos(elevation) * maxRadius;
    g.DrawEllipse(circlePen,(int)(centerX - radius) ,(int)(centerY - radius),(int)(2 * radius),(int)( 2*  radius));
   }
   //90 degrees elevation reticule
   g.DrawLine(circlePen,new Point(centerX-3,centerY),new Point(centerX + 3,centerY));
   g.DrawLine(circlePen,new Point(centerX,centerY-3),new Point(centerX,centerY+3));

   Pen satellitePen = new Pen(System.Drawing.Color.LightGoldenrodYellow,4);

   foreach(Satellite sat in protocol.GPGSV.Satellites.Values)
   {   
    //if has a listitem
    ListViewItem lvItem = (ListViewItem)sat.Thing;

    if(null == lvItem)
    {
     lvItem =  new ListViewItem
      (
       new string[]
       {
        sat.Id.ToString() ,
        sat.Elevation.ToString(),
        sat.Azimuth.ToString(),
        sat.Used.ToString()
       }
      );

     listSatellites.Items.Add(lvItem);
     
     sat.Thing = lvItem;//lvItem;
    }
    else
    {
     lvItem.Text = sat.Id.ToString();
     lvItem.SubItems[1].Text = sat.Elevation.ToString();
     lvItem.SubItems[2].Text = sat.Azimuth.ToString();
     lvItem.SubItems[3].Text = sat.Used.ToString();
    }

    //draw satellites
    double h = (double)System.Math.Cos((sat.Elevation*Math.PI)/180) * maxRadius;
    
    int satX = (int)(centerX + h * Math.Sin((sat.Azimuth * Math.PI)/180));
    int satY = (int)(centerY - h * Math.Cos((sat.Azimuth * Math.PI)/180));

    g.DrawRectangle(satellitePen,satX,satY, 4,4);

                g.DrawString(sat.Id.ToString(), new Font("Verdana", 8, FontStyle.Regular), new System.Drawing.SolidBrush(Color.Black), new Point(satX + 5, satY + 5));
   }
  }

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