For example, you may want to know exactly how many satellites are used in the location fix, by reading the 8th term in a GPGGA type sentence. Different GPS receivers will output different types of sentences. If you want to access other than GPRMC sentences only, you can use some additional routines. Returns direction to a given position on Earth Advanced Use Returns distance to a given position on Earth They are great for many projects! Given the last GPRMC sentence received, they simply tell you how far a geographic point is, and in what direction you should travel to get there. I included easy-to-use routines for geographic distance and course calculation. Returns direction of movement Distance and Direction Calculations For most projects, or if you are new to dealing with GPS data, these routines are all you need. For example, they contain your exact position, speed, and direction of movement. GPRMC type sentences are available from every GPS receiver, and for most applications they provide all the data you need. These routines provide easy access to 'GPRMC' type sentences. Just look into the example code provided with them to see how to use them.ĭecodes data from GPS receiver GPRMC Routines Basically, you set up a data connection of type NMEA and then use the routine decode() to interpret data from the GPS. These two constructs together form the heart of the library. It does not contain the "distance_to" and "course_to" functions, however. It runs fine on Wiring boards.īased on my NMEA library, Mikal Hart created TinyGPS for Arduino. I do not have an Arduino board, so I could not test it, but I heard reports that Arduino's do not have enough memory. This library was developed for Wiring boards, the more powerful predecessor of Arduino. All routines come with example code of how to use them. The NMEA:: library contains two basic constructs for connecting to a GPS's data stream, some routines for decoding sentences of type GPRMC specifically, some routines for calculating directions and distances, and several routines decoding for more advanced sentence types. Output from a GPS receiver will typically appear every second and contain different types of sentences. The library searches for 'sentences' in the output of a GPS receiver, and does checksum verification. This library makes it possible to write GPS applications for your Wiring i/o board, without knowing exactly how the NMEA protocol works. NMEA 0183 is the standard output protocol of GPS devices. NMEA:: Library for easy decoding of GPS data on the Wiring i/o boardīy Maarten Lamers, The Netherlands (2008/2009) IT DOES NOT REFLECT MY CURRENT INTERESTS OR KNOWLEDGE! Log.writeToLog("Exception error message: " + exc.// NOTE: THIS IS A LEGACY PAGE FROM 2008/2009, AVAILABLE ONLY FOR ARCHIVING REASONS. Log.writeToLog("Exception caused by sentence:" + sentence) Return String.Equals(checksum.ToString("X2"), CheckToCompare, StringComparison.OrdinalIgnoreCase) Log.writeToLog("Obtained CheckSum: " + CheckToCompare) Log.writeToLog("Checksum: " + checksum.ToString("X2")) String CheckToCompare = Words įor (int i = 1 i < (Words.Length - 2) i++) Private static bool IsValid(string sentence) Calculates the checksum for a sentence Returns True if a sentence's checksum matches the I'm using the idea from Codepedia - Calculating and Validating nmea sentences. The problem that i have is that my nmea message validator gives me an wrong checksum. I'm trying to write my own nmea parser,since i only need some info from the gps, and don't need to interpret all messages.
0 Comments
Leave a Reply. |