VisualGPS Readme

VisualGPS

VisualGPS has two modes of operation. The first, where Visual GPS communicates with a GPS receiver and second where VisualGPS reads NMEA sentences from a file. For VisualGPS to communicate with a GPS receiver, the GPS receiver must have ability to send NMEA data sentences. Currently the valid NMEA sentences supported are as follows:

  • GPGGA - Global Positioning System Fix Data
  • GPGSA - GNSS DOP and Active Satellites
  • GPGSV - GNSS Satellites in View

Connect VisualGPS to a GPS

First step is to connect the GPS receiver to the computer. Each GPS manufacture has their own way of connecting a cable from the GPS receiver to the computer. Although most all of them will connect to the serial port on a computer. Check with the GPS manufacture for details on cables.

The communication port must be set to the same port the GPS receiver is connected to. If no GPS receiver is present, VisualGPS has the ability to read a text file containing NMEA messages, demo mode. In any case, you need to access the Communications Dialog. This dialog is located in the Settings menu under Communications.

Standard communication settings for NMEA 0183 is 4800 baud, 8 data bits, 1 stop bit and no parity. If using a GPS receiver and it is connected to the computer, select the port the receiver is connected to and click OK. Note, VisualGPS will remember these communications settings and upon program start, will start to monitor for NMEA sentences.

NMEA File Logging

VisualGPS will also log all the NEMA sentences it receives to a file. This feature is also found in the Communication Settings Dialog. By checking the Enable Logging check box and setting the file name using the button to the right of the file name, a log file will be opened and NMEA data will be saved to that file.

This file can be used in playing back the data through the demo mode option. See below.

Running VisualGPS in Demo Mode

If no GPS receiver is present, then VisualGPS will run in a demo mode using a NMEA text file as input. VisualGPS provides a default file NMEA.TXT. This file has about five hours of data collected. Other NMEA text files may be used if desired. The NMEA.TXT file is provided for demonstration purpose and can be deleted. It is about a 4.3 MB file.
To run VisualGPS in demo mode:

  1. Select the Communications Dialog through the Settings menu. Click on Communications.
  2. Check the “Enable Demo Mode” check-box.
  3. Click on the “Browse” button.
  4. Select “NMEA.txt” file and click on Open. The file name will now read in the NMEA Capture File edit box.
  5. Click on OK

NOTE:
When VisualGPS is in demo mode and reading a file, it reads the file at a very fast rate and ignores time. One minute of acquired data will read in a few seconds. This will allow a time laps view of the captured data.

Using VisualGPS

VisualGPS has four major windows. Signal Quality, Navigation, Survey, Azimuth and Elevation. By clicking on the tool-bar, these windows will enable or brought into focus. Each window has its own abilities and functionality. Some windows like the Survey have pop-up menus that you can enable by using the right mouse button.