Diff: getGPS.cpp

Revision:

1:c142b1682312

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/getGPS.cpp	Wed Oct 30 01:42:40 2019 +0000
@@ -0,0 +1,58 @@
+#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し
+        i = 0;
+ 
+        /* gpa_data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') {
+            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（度部分） */
+        double latitude_dd = (double)(raw_latitude / 100);
+        double longitude_dd = (double)(raw_longitude / 100);
+ 
+        /* 座標2（分部分 → 度） */
+        double latitude_md = (raw_latitude - latitude_dd * 100) / 60;
+        double longitude_md = (raw_longitude - longitude_dd * 100) / 60;
+ 
+        /* 座標1 + 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
+}
+ 
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