1 files changed, 68 insertions, 0 deletions
diff --git a/mavlink/share/pyshared/pymavlink/examples/gpslock.py b/mavlink/share/pyshared/pymavlink/examples/gpslock.py
new file mode 100644
index 000000000..f15b29072
--- /dev/null
+++ b/mavlink/share/pyshared/pymavlink/examples/gpslock.py
@@ -0,0 +1,68 @@
+#!/usr/bin/env python
+
+'''
+show GPS lock events in a MAVLink log
+'''
+
+import sys, time, os
+
+# allow import from the parent directory, where mavlink.py is
+sys.path.insert(0, os.path.join(os.path.dirname(os.path.realpath(__file__)), '..'))
+
+from optparse import OptionParser
+parser = OptionParser("gpslock.py [options]")
+parser.add_option("--mav10", action='store_true', default=False, help="Use MAVLink protocol 1.0")
+
+(opts, args) = parser.parse_args()
+
+if opts.mav10:
+    os.environ['MAVLINK10'] = '1'
+import mavutil
+
+if len(args) < 1:
+    print("Usage: gpslock.py [options] <LOGFILE...>")
+    sys.exit(1)
+
+def lock_time(logfile):
+    '''work out gps lock times for a log file'''
+    print("Processing log %s" % filename)
+    mlog = mavutil.mavlink_connection(filename)
+
+    locked = False
+    start_time = 0.0
+    total_time = 0.0
+    t = None
+    m = mlog.recv_match(type='GPS_RAW')
+    unlock_time = time.mktime(time.localtime(m._timestamp))
+
+    while True:
+        m = mlog.recv_match(type='GPS_RAW')
+        if m is None:
+            if locked:
+                total_time += time.mktime(t) - start_time
+            if total_time > 0:
+                print("Lock time : %u:%02u" % (int(total_time)/60, int(total_time)%60))
+            return total_time
+        t = time.localtime(m._timestamp)
+        if m.fix_type == 2 and not locked:
+            print("Locked at %s after %u seconds" % (time.asctime(t),
+                                                     time.mktime(t) - unlock_time))
+            locked = True
+            start_time = time.mktime(t)
+        elif m.fix_type == 1 and locked:
+            print("Lost GPS lock at %s" % time.asctime(t))
+            locked = False
+            total_time += time.mktime(t) - start_time
+            unlock_time = time.mktime(t)
+        elif m.fix_type == 0 and locked:
+            print("Lost protocol lock at %s" % time.asctime(t))
+            locked = False
+            total_time += time.mktime(t) - start_time
+            unlock_time = time.mktime(t)
+    return total_time
+
+total = 0.0
+for filename in args:
+    total += lock_time(filename)
+
+print("Total time locked: %u:%02u" % (int(total)/60, int(total)%60))