BUG GPS Planning Meeting 1/27/99 | |||||||||||||||||
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System DesignApplicationsThe GPS system will consist of a control panel for the GPS hardware, a background application (server) to comunicate with the GPS hardware, and several viewer applications to visualize and process the data. The connections between these applications are diagrammed below. ![]() CommunicationViewers communicate with the GPS server using BMessages. A viewer application must register itself with the GPS server to receive data. Each packet of data must be requested from the server using a BMessage. If the viewer receives an error message, it must stop requesting data. When a viewer exits, it must also unregister itself with the server. The server will send an error message to the viewers that have registered themselves if it is exiting or if it has lost the connection to the GPS hardware. Saving Trip DataThe server does not record old data. Data can be saved to disk using the logger utility. The datafile format should be standardized so that other applications can read files in for trip data. The Blind Guide ApplicationOne possible use for the GPS system is a mobile guide for the blind. this application would provide audio-based cues about location or current status on a preprogrammed trip. Text-to-speech technologiy could also be incorporated. A laptop computer running the BeOS would be necessary to test the system. |