Fixed discord invite link

stability improvements

README.rst

@@ -7,7 +7,7 @@ Introduction
     :alt: Documentation Status
 
 .. image :: https://img.shields.io/discord/327254708534116352.svg
-    :target: https://discord.gg/nBQh6qu
+    :target: https://adafru.it/discord
     :alt: Discord
 
 .. image:: https://github.com/adafruit/Adafruit_CircuitPython_GPS/workflows/Build%20CI/badge.svg

adafruit_gps.py

@@ -141,7 +141,7 @@ class GPS:
         # return sentence
         if data_type in (
             b"GPGLL",
-            b"GNGGL",
+            b"GNGLL",
         ):  # GLL, Geographic Position – Latitude/Longitude
             self._parse_gpgll(args)
         elif data_type in (b"GPRMC", b"GNRMC"):  # RMC, minimum location info
@@ -260,7 +260,7 @@ class GPS:
 
     def _parse_gpgll(self, args):
         data = args.split(",")
-        if data is None or data[0] is None:
+        if data is None or data[0] is None or (data[0] == ""):
             return  # Unexpected number of params.
 
         # Parse latitude and longitude.
@@ -295,7 +295,7 @@ class GPS:
         # Parse the arguments (everything after data type) for NMEA GPRMC
         # minimum location fix sentence.
         data = args.split(",")
-        if data is None or len(data) < 11 or data[0] is None:
+        if data is None or len(data) < 11 or data[0] is None or (data[0] == ""):
             return  # Unexpected number of params.
         # Parse fix time.
         time_utc = int(_parse_float(data[0]))
@@ -374,7 +374,7 @@ class GPS:
         # Parse the arguments (everything after data type) for NMEA GPGGA
         # 3D location fix sentence.
         data = args.split(",")
-        if data is None or len(data) != 14:
+        if data is None or len(data) != 14 or (data[0] == ""):
             return  # Unexpected number of params.
         # Parse fix time.
         time_utc = int(_parse_float(data[0]))
@@ -421,7 +421,7 @@ class GPS:
 
     def _parse_gpgsa(self, args):
         data = args.split(",")
-        if data is None:
+        if data is None or (data[0] == ""):
             return  # Unexpected number of params
 
         # Parse selection mode
@@ -444,7 +444,7 @@ class GPS:
         # Parse the arguments (everything after data type) for NMEA GPGGA
         # 3D location fix sentence.
         data = args.split(",")
-        if data is None:
+        if data is None or (data[0] == ""):
             return  # Unexpected number of params.
 
         # Parse number of messages