GPS

<html><head> <title>Overview</title> <meta name="generator" content="HelpMaker.net" > <meta name="keywords" content="Overview," ></head> <body bgcolor="FFFCEA" > <table width="100%" border="0" cellspacing="0" cellpadding="2" bgcolor="C0C0C0" > <tr> <td align="left" > <div align="left" ><font face="Arial" color="#010101" size="4" ><span style="font-size:14pt" >Overview</span></font><font color="#010101" ></font></div> </td> <td align="right" > <font face="Arial" size="2" >   <a href="altitude.htm">Next</a> </font> </td> </tr></table> <hr><div align="left" ><font face="Times New Roman" color="#010101" ><span style="font-size:12pt" >The GPS library decodes a standard NMEA 0183 string received from the GPS receiver.</span></font><font color="#010101" ></font></div><div align="left" ><font face="Times New Roman" color="#010101" ><span style="font-size:12pt" >The main function of this library is GPSStream.</span></font><font color="#010101" ></font></div><div align="left" ><font face="Times New Roman" color="#010101" ><span style="font-size:12pt" >This function receives the string received from the GPS and when the string includes enough data it updates all the properties and raises the GPSDecoded event.</span></font><font color="#010101" ></font></div><div align="left" ><font face="Times New Roman" color="#010101" ><span style="font-size:12pt" >Using the Converter library which is also included in this library you can convert geographic coordinates from Lat/Lon format to UTM format (and vice versa) and from different datums.</span></font><font color="#010101" ></font></div><div align="left" ><font face="Times New Roman" color="#010101" ><span style="font-size:12pt" >The GPS library decodes the GPRMC and the GPGGA sentences.</span></font><font color="#010101" ></font></div><div align="left" ><font face="Times New Roman" color="#010101" ><span style="font-size:12pt" >If you need to decode other sentences you can use the StrSplit method which will split a string into words.</span></font><font color="#010101" ></font></div><div align="left" ><font face="Times New Roman" color="#010101" ><span style="font-size:12pt" >The data from the GPS is received using the Serial library and the InputString method.</span></font><font color="#010101" ></font></div><div align="left" ><font face="Times New Roman" color="#010101" ><span style="font-size:12pt" >The following example demonstrates the most straightforward way to handle the GPS data.</span></font><font color="#010101" ></font></div><div align="left" ><br></div><font color="#010101" ><div align="left" ></font><font face="Times New Roman" color="#010101" ><span style="font-size:12pt" >Example: Add a GPS object named gps, a Serial object named Serial and a Converter object named converter.</span></font><font color="#010101" ></font></div><div align="left" ><br><font color="#010101" ></font></div><div align="left" ><font face="Courier New" color="#0000ff" ><span style="font-size:10pt" >Sub </span></font><font face="Courier New" color="#010101" ><span style="font-size:10pt" >Globals</span></font><font color="#010101" ></font></div><div align="left" ><font face="Courier New" color="#010101" ><span style="font-size:10pt" >      </span></font><font face="Courier New" color="#0000ff" ><span style="font-size:10pt" >dim </span></font><font face="Courier New" color="#010101" ><span style="font-size:10pt" >ll(0) </span></font><font face="Courier New" color="#0000ff" ><span style="font-size:10pt" >as </span></font><font face="Courier New" color="#010101" ><span style="font-size:10pt" >double, utm(0) </span></font><font face="Courier New" color="#0000ff" ><span style="font-size:10pt" >as </span></font><font face="Courier New" color="#010101" ><span style="font-size:10pt" >double</span></font><font color="#010101" ></font></div><div align="left" ><font face="Courier New" color="#0000ff" ><span style="font-size:10pt" >End Sub</span></font><font color="#010101" ></font></div><div align="left" ><br></div><font color="#010101" ><div align="left" ></font><font face="Courier New" color="#0000ff" ><span style="font-size:10pt" >Sub </span></font><font face="Courier New" color="#010101" ><span style="font-size:10pt" >App_Start</span></font><font color="#010101" ></font></div><div align="left" ><font face="Courier New" color="#010101" ><span style="font-size:10pt" >      Form1.Show</span></font><font color="#010101" ></font></div><div align="left" ><font face="Courier New" color="#010101" ><span style="font-size:10pt" >      </span></font><font face="Courier New" color="#0000ff" ><span style="font-size:10pt" >If cppc</span></font><font face="Courier New" color="#010101" ><span style="font-size:10pt" > = true </span></font><font face="Courier New" color="#0000ff" ><span style="font-size:10pt" >then </span></font><font face="Courier New" color="#010101" ><span style="font-size:10pt" >port = 8 </span></font><font face="Courier New" color="#0000ff" ><span style="font-size:10pt" >else </span></font><font face="Courier New" color="#010101" ><span style="font-size:10pt" >port = 5 </span></font><font face="Courier New" color="#008000" ><span style="font-size:10pt" >'Change it to fit your ports numbers.</span></font><font color="#010101" ></font></div><div align="left" ><font face="Courier New" color="#010101" ><span style="font-size:10pt" >      Serial.New2(port,9600,"N",8,1)</span></font><font color="#010101" ></font></div><div align="left" ><font face="Courier New" color="#010101" ><span style="font-size:10pt" >      Serial.PortOpen = true</span></font><font color="#010101" ></font></div><div align="left" ><font face="Courier New" color="#010101" ><span style="font-size:10pt" >      gps.New1</span></font><font color="#010101" ></font></div><div align="left" ><font face="Courier New" color="#010101" ><span style="font-size:10pt" >      converter.New1</span></font><font color="#010101" ></font></div><div align="left" ><font face="Courier New" color="#010101" ><span style="font-size:10pt" >      </span></font><font face="Courier New" color="#0000ff" ><span style="font-size:10pt" >AddTimer</span></font><font face="Courier New" color="#010101" ><span style="font-size:10pt" >("Timer1")</span></font><font color="#010101" ></font></div><div align="left" ><font face="Courier New" color="#010101" ><span style="font-size:10pt" >      Timer1.Interval = 1000</span></font><font color="#010101" ></font></div><div align="left" ><font face="Courier New" color="#010101" ><span style="font-size:10pt" >      Timer1.Enabled = true</span></font><font color="#010101" ></font></div><div align="left" ><font face="Courier New" color="#0000ff" ><span style="font-size:10pt" >End Sub</span></font><font color="#010101" ></font></div><div align="left" ><br></div><font color="#010101" ><div align="left" ></font><font face="Courier New" color="#0000ff" ><span style="font-size:10pt" >Sub </span></font><font face="Courier New" color="#010101" ><span style="font-size:10pt" >Timer1_Tick</span></font><font color="#010101" ></font></div><div align="left" ><font face="Courier New" color="#010101" ><span style="font-size:10pt" >      </span></font><font face="Courier New" color="#0000ff" ><span style="font-size:10pt" >if </span></font><font face="Courier New" color="#010101" ><span style="font-size:10pt" >Serial.InBufferCount>0 </span></font><font face="Courier New" color="#0000ff" ><span style="font-size:10pt" >then</span></font><font face="Courier New" color="#010101" ><span style="font-size:10pt" > </span></font><font color="#010101" ></font></div><div align="left" ><font face="Courier New" color="#010101" ><span style="font-size:10pt" >            gps.GPSStream(Serial.InputString)</span></font><font color="#010101" ></font></div><div align="left" ><font face="Courier New" color="#010101" ><span style="font-size:10pt" >      </span></font><font face="Courier New" color="#0000ff" ><span style="font-size:10pt" >end if</span></font><font color="#010101" ></font></div><div align="left" ><font face="Courier New" color="#0000ff" ><span style="font-size:10pt" >End Sub</span></font><font color="#010101" ></font></div><div align="left" ><br></div><font color="#010101" ><div align="left" ></font><font face="Courier New" color="#0000ff" ><span style="font-size:10pt" >Sub </span></font><font face="Courier New" color="#010101" ><span style="font-size:10pt" >GPS_GPSDecoded</span></font><font color="#010101" ></font></div><div align="left" ><font face="Courier New" color="#010101" ><span style="font-size:10pt" >      ListBox1.Clear</span></font><font color="#010101" ></font></div><div align="left" ><font face="Courier New" color="#010101" ><span style="font-size:10pt" >      ListBox1.add("status: "& gps.status)</span></font><font color="#010101" ></font></div><div align="left" ><font face="Courier New" color="#010101" ><span style="font-size:10pt" >      ListBox1.Add("Number Of Satellites: " & gps.NumberOfSatellites)</span></font><font color="#010101" ></font></div><div align="left" ><font face="Courier New" color="#010101" ><span style="font-size:10pt" >      ListBox1.Add("Time: " & gps.UTCTime)</span></font><font color="#010101" ></font></div><div align="left" ><font face="Courier New" color="#010101" ><span style="font-size:10pt" >      ListBox1.add("lat: " & gps.latitude)</span></font><font color="#010101" ></font></div><div align="left" ><font face="Courier New" color="#010101" ><span style="font-size:10pt" >      ListBox1.add("lon: " & gps.longitude)</span></font><font color="#010101" ></font></div><div align="left" ><font face="Courier New" color="#010101" ><span style="font-size:10pt" >      ListBox1.add("dlat: "& gps.DecimalLatitude)</span></font><font color="#010101" ></font></div><div align="left" ><font face="Courier New" color="#010101" ><span style="font-size:10pt" >      ListBox1.Add("dlon: " & gps.DecimalLongitude)</span></font><font color="#010101" ></font></div><div align="left" ><font face="Courier New" color="#010101" ><span style="font-size:10pt" >      ListBox1.add("speed: "& gps.speedoverground)</span></font><font color="#010101" ></font></div><div align="left" ><font face="Courier New" color="#010101" ><span style="font-size:10pt" >      utm() = Converter.WGS84LatLonToUTM(gps.DecimalLatitude,gps.DecimalLongitude)</span></font><font color="#010101" ></font></div><div align="left" ><font face="Courier New" color="#010101" ><span style="font-size:10pt" >      ListBox1.Add("XZone: " & utm(0))</span></font><font color="#010101" ></font></div><div align="left" ><font face="Courier New" color="#010101" ><span style="font-size:10pt" >      ListBox1.Add("UTMX: " & utm(1))</span></font><font color="#010101" ></font></div><div align="left" ><font face="Courier New" color="#010101" ><span style="font-size:10pt" >      ListBox1.Add("YZone: " & </span></font><font face="Courier New" color="#0000ff" ><span style="font-size:10pt" >chr</span></font><font face="Courier New" color="#010101" ><span style="font-size:10pt" >(utm(2)))</span></font><font color="#010101" ></font></div><div align="left" ><font face="Courier New" color="#010101" ><span style="font-size:10pt" >      ListBox1.Add("UTMY: " & utm(3))</span></font><font color="#010101" ></font></div><div align="left" ><font face="Courier New" color="#0000ff" ><span style="font-size:10pt" >End Sub</span></font><font color="#010101" ></font></div> </body></html>