updated gps.dart

lib/src/serial/gps.dart

@@ -0,0 +1,61 @@
+import "dart:convert";
+import "dart:io";
+
+const testInput = r"$GNGGA,000957.00,4205.21462,N,07558.04134,W,1,10,1.00,298.7,M,-34.4,M,,*7C";
+const serialPort = "/dev/cu.usbmodem14201";
+
+class Coordinates {
+    final double latitude;
+    final double longitude;
+    final double altitude;
+    const Coordinates(this.latitude, this.longitude, this.altitude);
+
+    @override
+    String toString() => "Latitude: $latitude, Longitude: $longitude, Altitude: $altitude";
+}
+
+class GpsReader {
+    Coordinates? coordinates;
+    Coordinates? parseNmeaToDecimal(String nmeaSentence) {
+        final parts = nmeaSentence.split(",");
+        final tag = parts.first;
+        if (tag.endsWith("GGA")) {
+            return Coordinates(
+                nmeaToDecimal(double.tryParse(parts[2]) ?? 0.0), 
+                nmeaToDecimal(double.tryParse(parts[4]) ?? 0.0),
+                double.tryParse(parts[9]) ?? 0.0,
+            );
+        } else if (tag.endsWith("RMC")) {
+            return Coordinates(
+                nmeaToDecimal(double.tryParse(parts[3]) ?? 0.0), 
+                nmeaToDecimal(double.tryParse(parts[5]) ?? 0.0),
+                double.tryParse(parts[9]) ?? 0.0,
+            );
+        } else {
+            return null;
+        }
+    }
+    double nmeaToDecimal(double nmeaValue) {
+        final degrees = nmeaValue ~/ 100;
+        final minutes = nmeaValue % 100;
+        return degrees + minutes / 60.0;
+    }
+
+    Future <void> init(List<String> args) async {
+        if (args.contains("-t") || args.contains("--test")) {
+            this.coordinates = parseNmeaToDecimal(testInput);
+            print(coordinates); 
+        } else {
+            final process = await Process.start("cat", [serialPort]);
+            process.stdout.transform(utf8.decoder).transform(const LineSplitter()).listen((line) {
+            this.coordinates = parseNmeaToDecimal(line);
+            if (coordinates != null) print(coordinates);  
+            });
+        }
+    }
+}
+
+void main(List<String> args) {
+  final reader = GpsReader();
+  reader.init(args);
+}