nmea

问题 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. The problem that i have is that my nmea message validator gives me an wrong checksum. Can someone see what i'm droing wrong? I'm using the idea from Codepedia - Calculating and Validating nmea sentences. // Returns True if a sentence's checksum matches the // calculated checksum // Calculates the checksum for a sentence private static bool IsValid(string sentence) { if

问题 I have a GPS receptor, which send me NMEA frames. My code retrieve these ones, but in a really strange form : I am using PuTTY to see the NMEA frames received by my receptor, and there is no problem. EDIT - Here is the code I am using : public class GPSFrame extends Observable implements Runnable { static Thread myThread=null; static BufferedReader br; static BufferedWriter wr; static PrintWriter out; static InputStreamReader isr; static OutputStreamWriter osw; static java.io.RandomAccessFile

问题 Hy everybody! I wrote a small gps application in simple C++, what switch the protocoll, send command to the gps chip...etc. The write to the GPS port is working good. But when I try to read the port (for check the accepted commands) I receive a lot of stupid characters. Normally an NMEA output message is something like this: $GPGLL,4916.45,N,12311.12,W,225444,A And I received similar: 1C0CFC14 I dont know whats wrong... This part of my code is the next: LPCVOID buffer[100]; ReadFile(hSerial,

问题 i am trying to parse the incoming GPGGA NMEA GPS string using Arduino uno and below code. What i am trying to do is that i am using only GPGGA NMEA string to get the values of Latitude, longitude and altitude.In my below code, i had put certain checks to check if incoming string is GPGGA or not, and then store the further string in a array which can be further parsed suing strtok function and all the 3 GPS coordinates can be easily find out. But i am unable to figure out how to store only

问题 I do a lot of location aware computing, often incorporating GPS. I have my own little simple NMEA parser that doesn't do anything special - just transforms the GPS specific sentences into usable numbers, flags, and so forth. However, there is a lot of active development done on projects such as GPSD and Gypsy. If GPS were a simple matter, the projects would have finished long ago and simply gone into maintenance mode. What do they know/do that I don't know about, and therefore my code doesn't

问题 I've asked a similar question about it : Can't affect values to a simple Double[] table which is always null I have a TXT file containing NMEA frames. I retrieve the latitude and the longitude of $GPGGA and $GPRMC frames. Then I convert the latitude and longitude into Decimal Degrees. The first version of my code is working great. Then I made a second one, more structured, but which doesn't work. Here is the second version of my code which doesn't work : /** * Updating position on Google Maps

问题 I am working on a program that reads gps data. A NMEA string returns time like this: 34658.00. My parser treats that as a double InputLine = "\\$GPGGA,34658.00,5106.9792434234,N,11402.3003,W,2,09,1.0,1048.47,M,-16.27,M,08,AAAA*60"; //NMEA string //inputLine=input.readLine(); if(inputLine.contains("$GPGGA")) { String gpsgga = inputLine.replace("\\", ""); String[] gga = gpsgga.split(","); String utc_time = gga[1]; if (!gga[1].isEmpty()) { Double satTime = Double.parseDouble(utc_time); gpsData

问题 I am working with an external GPS, since they are far more accurate. I already have the bluetooth connection worked out, but now I'm stuck in a flood of NMEA formatted messages. It seems like, since you can get NMEA out of the built in GPS stack, that there must be a way to get a Location given a NMEA message. How do I go about converting my NMEA messages into useful Location objects? 回答1: NMEA is quite easy to parse. There are various types of sentences for different things. For location

问题 I need to create a c gps nmea parser for a board I'm working on (Cubietruck with armbian debian jessie 8.0) . Based on several examples I found on the internet I concluded in the following: #include <stdio.h> #include <stdint.h> #include <stdlib.h> #include <signal.h> #include <sys/types.h> #include <sys/stat.h> #include <sys/ioctl.h> #include <sys/fcntl.h> #include <termios.h> #include <unistd.h> #include <string.h> int fd = -1; int end_of_loop= 0; void sig_handler(int sig) { if(sig ==

问题 I was posting similar post already. And I did get an answer in theory but I really need somone to help me. So I am using this EXAMPLE for testing my GPS. What I want to do is how to get standard decimal values like 56,322415 for latitude and longitude. Because now I am getting 5304,254 value. I need it in this form because I will use this for Google maps. Can you check code and tell me what should I left out or how to convert it to WGS84 format. Thank you. EDIT: Here is the picture that is