add: Trimble EVT message (TNLEVT) (#165)

* add: Trimble EVT message (TNLEVT)

* fix: during first leap seconds of the day UTC date can be wrong

* fix: remove presumptious fix and datestamp derivative

pynmea2/types/proprietary/tnl.py

@@ -181,3 +181,32 @@ class TNLPJT(TNL):
         ('Coordinate System', 'coord_name'),
         ('Project Name', 'project_name'),
     )
+
+class TNLEVT(TNL, DatetimeFix):
+    """
+        Trimble EVT message (used for events like hardware triggers)
+
+        0 	Talker ID $PTNL
+        1 	Message ID EVT
+        2 	Event time. UTC time of event in format hhmmss.ssssss
+        3 	Port number. Port event markers receiver: "1" or "2" (optional),
+                if two ports are available.
+        4 	NNNNNN. Incremental number of events on each independent port.
+        5 	WWWW. Week number of event (since 06 January 1980).
+        6 	Day of week. Days denoted 0 = Sunday…6 = Saturday.
+        7 	Leap second. UTC Leap Second offset from GPS time,
+        8 	The checksum data, always begins with *
+
+        Example message:
+        $PTNL,EVT,131007.999785,2,460,2181,5,18*72
+    """
+    fields = (
+        ('Empty', '_'),
+        ('Sentence Type', 'type'),
+        ('Timestamp', 'timestamp', timestamp),
+        ('Port Number', 'port_num', int),
+        ('Event Number', 'event_num', int),
+        ('GPS Week Number', 'gps_week_num', int),
+        ('GPS Day of the Week', 'gps_day_num', int),
+        ('Leap Seconds', 'leap_secs', int)
+    )

test/test_tnl.py

@@ -107,3 +107,16 @@ def test_tnlvhd():
     assert msg.gps_quality == '3'
     assert msg.num_sats == 7
     assert msg.pdop == 2.4
+
+def test_tnlevt():
+    data = '$PTNL,EVT,131007.999785,2,460,2181,5,18*72'
+    msg = pynmea2.parse(data)
+    assert type(msg) == pynmea2.tnl.TNLEVT
+    assert msg.manufacturer == 'TNL'
+    assert msg.type == 'EVT'
+    assert msg.timestamp == datetime.time(13, 10, 7, 999785, tzinfo=datetime.timezone.utc)
+    assert msg.port_num == 2
+    assert msg.event_num == 460
+    assert msg.gps_week_num == 2181
+    assert msg.gps_day_num == 5
+    assert msg.leap_secs == 18