GPS Toolkit - Add GPS and coordinate conversion functionality to your software

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GPS Toolkit Introduction

The Eye4Software GPS toolkit is a GPS SDK (Software Developer Kit) which allows software developers to add GPS and coordinate conversion functionality to their programs or scripts, without the need to have any knowledge on geodesy, serial communication protocols, NMEA0183 sentences and other GPS protocols.

The GPS toolkit offers the following features:

  • Retrieve GPS information such as position, course, altitude and speed;
  • Retrieve GPS satellite information, such as azimuth, elevation and signal strength;
  • Retrieve GPS time for PC time synchronization;
  • Decode NMEA0183 data strings received from GPS, or directly from other sources;
  • Convert (GPS) coordinates from one map datum to another;
  • Convert coordinates between NAD83 and NAD27 using NADCON correction files;
  • Convert coordinates between NAD83 and NAD83(HARN) using HARN/HPGN correction files;
  • Convert coordinates between different map datums using NTv2 correction files;
  • Convert (GPS) coordinates from one coordinate system or map projection to another;
  • Convert (GPS) coordinates to U.S. State Plane Coordinate System (SPCS27 or SPCS83);
  • Convert (GPS) coordinates to UTM coordinates;
  • Built-in support for more then 500 map datums and 5000 map grids;
  • Simple distribution, you only have to ship a single DLL file with your application;
  • Convert datafiles from one coordinate system to another using a simple script;
  • Unit conversions;
  • Course and distance calculations.

The GPS control can be used from many programming environments, such as Visual Basic, Visual C++, Visual Basic .NET, Visual C# .NET, Borland C++ Builder, Borland Delphi and VBA (Excel, Access), but also web oriented applications such as ASP, ASP.NET and PHP, and all other programming environments that support ActiveX controls, can be used.

Demo Application Retrieve position information Add Coordinate Conversion Log NMEA 0183 data
A demo application to retrieve data from your GPS is shipped with the toolkit. Retrieve GPS position information from your (.NET) Windows applications. Add support for coordinate conversions to your (.NET) Windows applications or scripts. All received GPS data can be logged into a textfile for later processing or troubleshooting.

GPS Toolkit Features

Perform GPS coordinate conversions

The latitude and longitude coordinates from either the GPS or set by the user, can be converted to any map datum or map grid around (for instance to UTM or SPCS), by just using the built in "GpsProjection" object.

The GPS Toolkit contains a database with over 3500 map grid and 300 map datum definitions. The database is integrated in the core DLL. You can use all these map grids and map datums directly from your software with only a few lines of code. In case a grid or datum is not in this database, you will be able to define it by yourself by setting its parameters.

The map projections supported by the software include:

Retrieve and decode position data from a GPS device

The toolkit will handle all serial data from the GPS device, and converts the received NMEA 0183 sentences into usable data, which can be used directly in your software and / or scripts:

  • Latitude and Longitude coordinates;
  • Altitude and geoid height;
  • Course over ground ( SOG );
  • Speed over ground ( COG );
  • Magnetic Variation;
  • Date and time;
  • GPS Fix type;
  • Number of GPS satellites in view;
  • HDOP, VDOP and PDOP;
  • Estimated position error (Garmin only);
  • DGPS beacon id, speed and frequency;
  • Satellite information like signal strength, azimuth and elevation.

Speed and altitude data can be converted to various units like: Knots, Kmh, Mph and Meters per second for speed, for altitude: Meters and Feet.

Use Garmin GPS devices connected through USB

Most Garmin GPS devices are shipped with an USB connection instead of a serial port these days. The protocol used by Garmin is called PVT which means: "Position - Velocity - Time". The toolkit can communicate directly with the USB driver, without the need to use Spanner software, to read position data from these GPS devices. The data which can be retrieved over the PVT protocol is the same as described for the NMEA 0183 protocol above.

Miscellaneous GPS Utilities

The toolkit contains a GPS Utilities object to perform other GPS software related tasks, such as:

  • Unit conversions;
  • Convert different latitude/longitude formats to decimal;
  • Convert decimal to different latitude/longitude formats;
  • Calculate bearing between two points using great circle calculations;
  • Calculate distance between two points using Vincenty's formula.

Code samples

The package includes code samples for the following programming environments:

Microsoft Visual C++  View code...
Microsoft Visual Basic  View code...
Microsoft Visual Basic .Net  View code...
Microsoft Visual C# .Net  View code...
VBScript  View code...
Borland Delphi  View code...
VBA (Excel)  View code...
HTML/JavaScript  View code...
PHP (Windows Only)  View code...
ASP (Active Server Pages)  View code...


To retrieve GPS information, you need a NMEA 0183 compatible GPS device (most GPS devices around support the NMEA 0183 protocol) attached to your computer using an USB, Bluetooth or RS232 serial connection, or a Garmin GPS device connected directly to the computer using its USB interface. When the GPS Toolkit is used to perform transformations between different map datums and / or map grids only, no hardware is required.

The GPS Toolkit can be used on 32 bit and 64 bit Windows 2000, Windows XP, Windows 2003 Server, Windows Vista, Windows 7 or Windows 2008 Server Operating Systems. To run the .NET sample applications you must have .NET framework 2.0 or higher installed. The package includes two copies of the GPS SDK, a 32 bit or X86 version (GpsCtl32.dll) and a 64 bit or X64 version (GpsCtl64.dll).


A fully functional 30-day trial version can be downloaded free of charge from the downloads page.

Pricing, licensing and ordering

Pricing, licensing and ordering information can be found on our sales page.