ubus: display only available information

GPS receivers may not provide all possible data, some take more time
and some are irrelevant for some applications and are never sent by
some GPS receivers (eg. equipment found in maritime context doesn't
report elevation). Only populate attributes for which data is actually
available.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

diff --git a/main.c b/main.c
index 7696cbc9c26282e1a55f68e2abdeebbb6517f862..2ab0f8cf388099cf8e033d234ee07a77daf3509c 100644 (file)
--- a/main.c
+++ b/main.c
@@ -52,15 +52,20 @@ gps_info(struct ubus_context *ctx, struct ubus_object *obj,
 
        blob_buf_init(&b, 0);
 
-       if (!stamp.tv_sec) {
+       if (!stamp.tv_sec || !gps_fields) {
                blobmsg_add_u8(&b, "signal", 0);
        } else {
                blobmsg_add_u32(&b, "age", now.tv_sec - stamp.tv_sec);
-               blobmsg_add_string(&b, "latitude", latitude);
-               blobmsg_add_string(&b, "longitude", longitude);
-               blobmsg_add_string(&b, "elevation", elevation);
-               blobmsg_add_string(&b, "course", course);
-               blobmsg_add_string(&b, "speed", speed);
+               if (gps_fields & GPS_FIELD_LAT)
+                       blobmsg_add_string(&b, "latitude", latitude);
+               if (gps_fields & GPS_FIELD_LON)
+                       blobmsg_add_string(&b, "longitude", longitude);
+               if (gps_fields & GPS_FIELD_ALT)
+                       blobmsg_add_string(&b, "elevation", elevation);
+               if (gps_fields & GPS_FIELD_COG)
+                       blobmsg_add_string(&b, "course", course);
+               if (gps_fields & GPS_FIELD_SPD)
+                       blobmsg_add_string(&b, "speed", speed);
        }
        ubus_send_reply(ctx, req, b.head);
 

diff --git a/nmea.c b/nmea.c
index d51d936d2e69bcae34804a93d23d7f8df165c230..8e6160632f59b91f18be298d4192b24699258e63 100644 (file)
--- a/nmea.c
+++ b/nmea.c
@@ -54,6 +54,7 @@ struct nmea_param {
 static int nmea_bad_time;
 char longitude[33] = { 0 }, latitude[33] = { 0 }, course[17] = { 0 }, speed[17] = { 0 }, elevation[17] = { 0 };
 int gps_valid = 0;
+char gps_fields = 0;
 
 static void
 nmea_txt_cb(void)
@@ -119,6 +120,8 @@ parse_gps_coords(char *latstr, char *vhem, char *lonstr, char *hhem)
        snprintf(longitude, sizeof(longitude), "%f", lon);
 
        DEBUG(3, "position: %s %s\n", latitude, longitude);
+       gps_fields |= GPS_FIELD_LAT | GPS_FIELD_LON;
+
        gps_timestamp();
 }
 
@@ -220,6 +223,7 @@ nmea_gga_cb(void)
        if (!gps_valid)
                return;
        strncpy(elevation, nmea_params[9].str, sizeof(elevation));
+       gps_fields |= GPS_FIELD_ALT;
        DEBUG(4, "height: %s\n", elevation);
 }
 
@@ -230,6 +234,7 @@ nmea_vtg_cb(void)
                return;
        strncpy(course, nmea_params[1].str, sizeof(course));
        strncpy(speed, nmea_params[7].str, sizeof(speed));
+       gps_fields |= GPS_FIELD_COG | GPS_FIELD_SPD;
        DEBUG(4, "course: %s\n", course);
        DEBUG(4, "speed: %s\n", speed);
 }

diff --git a/nmea.h b/nmea.h
index 9f46d299983ef600d982ba798a4c86f6b1d92d11..2de06dce482b849c45318a6ee761741c4f7b725c 100644 (file)
--- a/nmea.h
+++ b/nmea.h
@@ -27,5 +27,11 @@ extern char longitude[33], latitude[33], course[17], speed[17], elevation[17];
 extern int nmea_open(char *dev, struct ustream_fd *s, speed_t speed);
 extern void gps_timestamp(void);
 extern unsigned int adjust_clock;
+extern char gps_fields;
+#define GPS_FIELD_LAT (1<<0)
+#define GPS_FIELD_LON (1<<1)
+#define GPS_FIELD_COG (1<<2)
+#define GPS_FIELD_SPD (1<<3)
+#define GPS_FIELD_ALT (1<<4)
 
 #endif