GPSCom2 v1.01 A freeware COM Library for GPS support  

IConnectionPointImplMT v1.03 A freeware IConnectionPoint implementation for ATL

Welcome to GPSCom2, a simple freeware COM based library which can be used to add GPS support to your Windows applications. GPSCom2 is a standard COM EXE developed in ATL in VC 2010. It is based on the design of the existing shareware GPSCom component of the author which has now been obsoleted by GPSCom2. GPSCom2 internally uses an advanced ATL class called IConnectionPointImplMT to support firing COM events from worker threads different that the threads on which the COM object was originally created. The GPSCom2 code internally used asynchronous IO when reading from the serial port to provide the best performance and avoids the need for polling. Included in the download is prebuilt GPSCom2 binaries for x86 and x64. The GPSCom2 component delivers a simple string value of a sentence back to client applications using the standard COM Connection Point notification mechanism. A set of MFC client classes further abstracts this to provide a simple C++ class with virtual functions for each type of NMEA sentence. These set of classes are provided in the GPSCom2Client\GPSCom2Client.h header file which you can simple include in your existing MFC applications. These classes provide comprehensive support for the following NMEA sentences: $GPRMC, $GPGGA, $GPGSV, $GPGLL, $GPVTG, $GPGSA, $GPGRS & $GPGST. All the parsing of these sentences is handled for you and standard virtual function and parsed structures are available for client applications to code against.

The enclosed zip file contains the GPSCom2 source code, and a x86 and x64 Unicode Release binary and a sample VC++ 2008 test app which exercises the MFC client classes.

Features

• Provides a very simple MFC client API to the out of process COM object hiding all the COM plumbing required to achieve this.
• Allows connections to GPS devices to be shared between multiple clients i.e. multiple client processes can share the one connection to the receivers serial port !!. This is achieved by the IGPSConnection::CreateConnection method which hands back existing connections if the port number requested matches an already open port.
• Standard COM Connection points are provided in the library to allow client apps to be notified in real time of incoming GPS NMEA sentences, but this plumbing is all hidden by the MFC client classes.
• Provides a concrete example on how COM collection classes should be implemented.
• Comprehensive support for the following NMEA sentences: $GPRMC, $GPGGA, $GPGSV, $GPGLL, $GPVTG, $GPGSA, $GPGRS & $GPGST. This is a pretty comprehensive set of NMEA sentences available from most GPS devices.
• Client apps can also poll the connection for the NMEA information if they so desire or hook into the virtual functions which get called when a specific sentence is received.
• Supports any standard GPS device which supports the NMEA 0183 standard and which presents its data on a Windows Serial Port (Physical or Virtual/Emulated).
• The GPSCom2 binary does not have any dependencies on ATL or MFC DLLs. It is a purely ATL based implementation unlike GPSCom and only takes dependencies on standard Windows DLLs.
• Will work with any version of Windows from Windows 2000 onwards.

Updates

V1.0 GPSCom2 / v1.03 IConnectionPointImplMP (1 May 2010)

• Initial public release of GPSCom2.
• IConnectionPointImplMP has been updated to work when "using namespace ATL" is now explicitly set in client code.
• IConnectionPointImplMP::GetInterfaceAt method has been reworked to surface a HRESULT as a return value. In addition the IDispatch pointer is now returned already wrapped in a CComPtr<IDispatch> smart pointer reference parameter. The instructions of how you recode the Fire_* methods have also been reworked.

V1.01 GPSCom2 (1 May 2010)

• Updated the CSentence::Time method to correctly handle centiseconds values
• Updated the CSentence::Angle method to correctly handle empty fields
• Fixed logic errors in CVTGSentence::Parse
• CSentence::Tokenize now removes all fields from the array before it starts parsing
• All places which parse a floating point number now handle empty fields