39 lines
1.3 KiB
ReStructuredText
39 lines
1.3 KiB
ReStructuredText
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.. _how_it_works:
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How it works
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============
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LwGPS parses raw data formatted as NMEA 0183 statements from GPS receivers. It supports up to ``4`` different statements:
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* ``GPGGA`` or ``GNGGA``: GPS fix data
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* ``GPGSA`` or ``GNGSA``: GPS active satellites and dillusion of position
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* ``GPGSV`` or ``GNGSV``: List of satellites in view zone
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* ``GPRMC`` or ``GNRMC``: Recommended minimum specific GPS/Transit data
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.. tip::
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By changing different configuration options, it is possible to disable some statements.
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Check :ref:`api_lwgps_opt` for more information.
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Application must assure to properly receive data from GPS receiver.
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Usually GPS receivers communicate with host embedded system with UART protocol and output directly formatted NMEA 0183 statements.
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.. note::
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Application must take care of properly receive data from GPS.
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Application must use :cpp:func:`lwgps_process` function for data processing. Function will:
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* Detect statement type, such as *GPGGA* or *GPGSV*
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* Parse all the terms of specific statement
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* Check valid CRC after each statement
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Programmer's model is as following:
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* Application receives data from GPS receiver
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* Application sends data to :cpp:func:`lwgps_process` function
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* Application uses processed data to display altitude, latitude, longitude, and other parameters
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Check :ref:`examples` for typical example
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.. toctree::
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:maxdepth: 2
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