altos: Allow sparse GPS data logging for TeleGPS

[fw/altos] / src / kernel / ao_gps_report_mega.c

diff --git a/src/kernel/ao_gps_report_mega.c b/src/kernel/ao_gps_report_mega.c
index 5e3c71bfa309e1ecb6f3fecb954dde596ff12283..cb0c0fd99722eb38efc3d949f79306970e501d42 100644 (file)
--- a/src/kernel/ao_gps_report_mega.c
+++ b/src/kernel/ao_gps_report_mega.c
@@ -18,6 +18,43 @@
 #include "ao.h"
 #include "ao_log.h"
 
+#ifndef GPS_SPARSE_LOG
+#define GPS_SPARSE_LOG 0
+#endif
+
+#if GPS_SPARSE_LOG
+static int32_t prev_lat, prev_lon, int16_t prev_alt;
+static uint8_t has_prev, unmoving;
+
+#define GPS_SPARSE_UNMOVING_REPORTS    10
+#define GPS_SPARSE_UNMOVING_GROUND     10
+#define GPS_SPARSE_UNMOVING_AIR                10
+
+static uint8_t
+ao_gps_sparse_should_log(int32_t lat, int32_t lon, int16_t alt)
+{
+       uint8_t ret = 1;
+
+       if (has_prev && ao_log_running) {
+               uint32_t        h = ao_distance(prev_lat, prev_lon, lat, lon);
+               uint16_t        v = alt > prev_alt ? (alt - prev_alt) : (prev_alt - alt);
+
+               if (h < GPS_SPARSE_UNMOVING_GROUND && v < GPS_SPARSE_UNMOVING_AIR) {
+                       if (unmoving < GPS_SPARSE_UNMOVING_REPORTS)
+                               ++unmoving;
+               } else
+                       unmoving = 0;
+       } else
+               unmoving = 0;
+
+       prev_lat = lat;
+       prev_lon = lon;
+       prev_alt = alt;
+       has_prev = 1;
+       return unmoving >= GPS_SPARSE_UNMOVING_REPORTS;
+}
+#endif
+
 void
 ao_gps_report_mega(void)
 {
@@ -38,7 +75,14 @@ ao_gps_report_mega(void)
                ao_gps_new = 0;
                ao_mutex_put(&ao_gps_mutex);
 
+#if GPS_SPARSE_LOG
+               /* Don't log data if GPS has a fix and hasn't moved for a while */
+               if ((gps_data.flags & AO_GPS_VALID) &&
+                   !ao_gps_sparse_should_log(gps_data.latitude, gps_data.longitude, gps_data.altitude))
+                       continue;
+#endif
                if ((new & AO_GPS_NEW_DATA) && (gps_data.flags & AO_GPS_VALID)) {
+
                        gps_log.tick = ao_gps_tick;
                        gps_log.type = AO_LOG_GPS_TIME;
                        gps_log.u.gps.latitude = gps_data.latitude;