gps

Dependencies:   mbed

getGPS.cpp

Committer:
naruu
Date:
2020-10-15
Revision:
3:c64909f39383
Parent:
0:77bff687ff05

File content as of revision 3:c64909f39383:

#include "mbed.h"
#include "getGPS.h"
 
GPS::GPS(PinName gpstx,PinName gpsrx): _gps(gpstx,gpsrx)
{
    latitude = 0;
    longitude = 0;
    _gps.baud(GPSBAUD);
    _gps.printf("$PMTK314,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0*29");
}
 
bool GPS::getgps()
{
    char gps_data[256];
    int i;
    
    do {
        while(_gps.getc() != '$'); //$マークまで読み飛ばす
        
        i = 0;
        
         /*gpsデータを初期化*/
        for(int j = 0; j < 256; j++){
            gps_data[j] = '\0';
             }
             
        /* NMEAから一行読み込み */
        while((gps_data[i] = _gps.getc()) != '\r')//受信データを格納、\rが出てくるまでループ
         {
            i++;
            if(i == 256) {
                i = 255;
                break;
            }
        }
    } while(strstr(gps_data, "GPGGA") == NULL); //GGAセンテンスまで一行ずつ読み込み続ける
    
    int rlock;
    char ns,ew;
    double w_time, raw_longitude, raw_latitude;
    int satnum;
    double hdop;
 
    if(sscanf(gps_data, "GPGGA, %lf, %lf, %c, %lf, %c, %d, %d, %lf", &w_time, &raw_latitude, &ns, &raw_longitude, &ew, &rlock, &satnum, &hdop) > 1) {
       /*座標1(度成分)*/
        double latitude_dd = (double)(raw_latitude / 100);
        double longitude_dd = (double)(raw_longitude / 100);
 
        /* 座標2(分成分 → 度)*/
        double latitude_md = (raw_latitude - latitude_dd * 100) / 60;
        double longitude_md = (raw_longitude - longitude_dd * 100) / 60;
 
        /* 座標1+座標2 */
        latitude = latitude_dd + latitude_md;
        longitude = longitude_dd + longitude_md;
 
        return true;
    } else
        return false; //GGAセンテンスの情報が欠けている時
}