feat: implementation of the Compass page

android/app/src/main/AndroidManifest.xml

@@ -36,6 +36,7 @@
         <meta-data
             android:name="flutterEmbedding"
             android:value="2" />
+
     </application>
     <!-- Required to query activities that can process text, see:
          https://developer.android.com/training/package-visibility and

lib/constants.dart

@@ -133,3 +133,7 @@ List<String> connectWithUs = [
   'Developers'
 ];
 String softwareLicenses = 'Software Licenses';
+String magnetometerError = 'Magnetometer error:';
+String accelerometerError = 'Accelerometer error:';
+String compassTitle = 'Compass';
+String parallelToGround = 'Select axes parallel to ground';

lib/main.dart

@@ -9,7 +9,7 @@ import 'package:pslab/view/oscilloscope_screen.dart';
 import 'package:pslab/view/settings_screen.dart';
 import 'package:pslab/view/about_us_screen.dart';
 import 'package:pslab/view/software_licenses_screen.dart';
-
+import 'package:pslab/view/compass_screen.dart';
 import 'constants.dart';
 
 void main() {
@@ -44,6 +44,7 @@ class MyApp extends StatelessWidget {
       routes: {
         '/': (context) => const InstrumentsScreen(),
         '/oscilloscope': (context) => const OscilloscopeScreen(),
+        '/compass': (context) => const CompassScreen(),
         '/connectDevice': (context) => const ConnectDeviceScreen(),
         '/faq': (context) => const FAQScreen(),
         '/settings': (context) => const SettingsScreen(),

lib/providers/compass_provider.dart

@@ -0,0 +1,169 @@
+import 'dart:async';
+import 'dart:math';
+import 'package:flutter/material.dart';
+import 'package:sensors_plus/sensors_plus.dart';
+import 'package:flutter/foundation.dart';
+import 'package:pslab/others/logger_service.dart';
+
+import '../constants.dart';
+
+class CompassProvider extends ChangeNotifier {
+  MagnetometerEvent _magnetometerEvent =
+      MagnetometerEvent(0, 0, 0, DateTime.now());
+  AccelerometerEvent _accelerometerEvent =
+      AccelerometerEvent(0, 0, 0, DateTime.now());
+  StreamSubscription? _magnetometerSubscription;
+  StreamSubscription? _accelerometerSubscription;
+  String _selectedAxis = 'X';
+  double _currentDegree = 0.0;
+  int _direction = 0;
+  double _smoothedHeading = 0.0;
+
+  MagnetometerEvent get magnetometerEvent => _magnetometerEvent;
+  AccelerometerEvent get accelerometerEvent => _accelerometerEvent;
+  String get selectedAxis => _selectedAxis;
+  double get currentDegree => _currentDegree;
+  int get direction => _direction;
+  double get smoothedHeading => _smoothedHeading;
+
+  void initializeSensors() {
+    _magnetometerSubscription = magnetometerEventStream().listen(
+      (event) {
+        _magnetometerEvent = event;
+        _updateCompassDirection();
+        notifyListeners();
+      },
+      onError: (error) {
+        logger.e("$magnetometerError: $error");
+      },
+      cancelOnError: true,
+    );
+
+    _accelerometerSubscription = accelerometerEventStream().listen(
+      (event) {
+        _accelerometerEvent = event;
+        _updateCompassDirection();
+        notifyListeners();
+      },
+      onError: (error) {
+        logger.e("$accelerometerError: $error");
+      },
+      cancelOnError: true,
+    );
+  }
+
+  void disposeSensors() {
+    _magnetometerSubscription?.cancel();
+    _accelerometerSubscription?.cancel();
+  }
+
+  @override
+  void dispose() {
+    disposeSensors();
+    super.dispose();
+  }
+
+  void _updateCompassDirection() {
+    double radians = _getRadiansForAxis(_selectedAxis);
+    double degrees = radians * (180 / pi);
+    if (degrees < 0) {
+      degrees += 360;
+    }
+
+    degrees = (degrees - 90) % 360;
+    if (degrees < 0) {
+      degrees += 360;
+    }
+
+    const double alpha = 0.45;
+    double angleDiff = degrees - _smoothedHeading;
+    if (angleDiff > 180) {
+      angleDiff -= 360;
+    } else if (angleDiff < -180) {
+      angleDiff += 360;
+    }
+    _smoothedHeading = _smoothedHeading + alpha * angleDiff;
+    if (_smoothedHeading >= 360) {
+      _smoothedHeading -= 360;
+    } else if (_smoothedHeading < 0) {
+      _smoothedHeading += 360;
+    }
+    switch (_selectedAxis) {
+      case 'X':
+        _currentDegree = -(_smoothedHeading * pi / 180);
+        break;
+      case 'Y':
+        _currentDegree = ((_smoothedHeading - 10) * pi / 180);
+        break;
+      case 'Z':
+        _currentDegree = -((_smoothedHeading + 90) * pi / 180);
+        break;
+    }
+  }
+
+  double _getRadiansForAxis(String axis) {
+    double ax = _accelerometerEvent.x;
+    double ay = _accelerometerEvent.y;
+    double az = _accelerometerEvent.z;
+    double mx = _magnetometerEvent.x;
+    double my = _magnetometerEvent.y;
+    double mz = _magnetometerEvent.z;
+
+    double pitch = atan2(ay, sqrt(ax * ax + az * az));
+    double roll = atan2(-ax, az);
+
+    double xH = mx * cos(pitch) + mz * sin(pitch);
+    double yH = mx * sin(roll) * sin(pitch) +
+        my * cos(roll) -
+        mz * sin(roll) * cos(pitch);
+    double zH = -mx * cos(roll) * sin(pitch) +
+        my * sin(roll) +
+        mz * cos(roll) * cos(pitch);
+
+    switch (axis) {
+      case 'X':
+        return atan2(yH, xH);
+      case 'Y':
+        return atan2(-xH, zH);
+      case 'Z':
+        return atan2(yH, -zH);
+      default:
+        return atan2(yH, xH);
+    }
+  }
+
+  double getDegreeForAxis(String axis) {
+    double radians = _getRadiansForAxis(axis);
+    double degree = radians * (180 / pi);
+
+    switch (axis) {
+      case 'X':
+        degree = (degree - 90) % 360;
+        break;
+      case 'Y':
+        degree = (-degree + 100) % 360;
+        break;
+      case 'Z':
+        degree = (degree + 90) % 360;
+        break;
+    }
+
+    return degree < 0 ? degree + 360 : degree;
+  }
+
+  void onAxisSelected(String axis) {
+    _selectedAxis = axis;
+    switch (axis) {
+      case 'X':
+        _direction = 0;
+        break;
+      case 'Y':
+        _direction = 1;
+        break;
+      case 'Z':
+        _direction = 2;
+        break;
+    }
+    notifyListeners();
+  }
+}