nmea: add GGA, RMC

pkgs/maps/nmea.fnl

@@ -58,6 +58,56 @@
 (local
  msg-types
  {
+  :GGA
+  (fn [fields]
+    (let [[utc lat latsign lon lonsign
+           fix-quality
+           total-space-vehicles
+           hdop
+           altitude _
+           geoidal-separation _
+           _ _ ] fields
+          latf (if (= lat "")
+                   nil
+                   (* (tonumber lat) 0.01 (case latsign :N 1 :S -1)))
+          lonf (if (= lon "")
+                   nil
+                   (* (tonumber lon) 0.01 (case lonsign :E 1 :W -1)))]
+      { :lat latf
+        :lon lonf
+        : fix-quality
+        :total-space-vehicles (try-number total-space-vehicles)
+        :hdop (try-number hdop)
+        :altitude (try-number altitude)
+        :geoidal-separation (try-number geoidal-separation)
+        }))
+
+  :RMC
+  (fn [[utc valid lat latsign lon lonsign
+        knots bearing-true date
+        magn-var magn-var-sign
+        mode nav-status &as fields]]
+    (let [latf (if (= lat "")
+                   nil
+                   (* (tonumber lat) 0.01 (case latsign :N 1 :S -1)))
+          lonf (if (= lon "")
+                   nil
+                   (* (tonumber lon) 0.01 (case lonsign :E 1 :W -1)))
+          magnetic-variation (if (= magn-var "")
+                                 nil
+                                 (* (tonumber magn-var)
+                                    (case magn-var-sign :E 1 :W -1)))]
+      { : utc
+        : valid
+        :lat latf
+        :lon lonf
+        :speed-knots (try-number knots)
+        :bearing-true (try-number bearing-true)
+        : date
+        : magnetic-variation
+        : mode
+        }))
+
   :GNS
   (fn [fields]
     (let [[utc lat latsign lon lonsign mode total-space-vehicles