Added Heart rate monitor basic functionality

lib/I_GUIDER/i_guider.dart

+import 'package:covidefender/pages/heart_rate/heart_rate_screen.dart';
 import 'package:covidefender/pages/mask_detect/invoker.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
@@ -18,13 +19,10 @@ class I_guider extends StatelessWidget {
               Expanded(
                 child: Container(
                   decoration: BoxDecoration(
-                    image: DecorationImage(
-                      image: AssetImage('lib/assets/images/hero.gif'),
-                      fit: BoxFit.cover
-                    )
-                  ),
+                      image: DecorationImage(
+                          image: AssetImage('lib/assets/images/hero.gif'),
+                          fit: BoxFit.cover)),
                   height: 300,
-
                 ),
               ),
             ],
@@ -66,7 +64,7 @@ class I_guider extends StatelessWidget {
                     minWidth: 100.0,
                     height: 150.0,
                     child: RaisedButton.icon(
-                      color: Colors.red[200],
+                      color: Colors.greenAccent,
                       icon: Icon(
                         Icons.face_unlock_sharp,
                         size: 60,
@@ -78,7 +76,12 @@ class I_guider extends StatelessWidget {
                       ),
                       onPressed: () {
                         print('face mask detection');
-                        Navigator.pushNamed(context, '/invoker');
+                        Navigator.push(
+                            context,
+                            MaterialPageRoute(
+                                builder: (context) => invoker())
+                        );
+                        // Navigator.pushNamed(context, '/invoker');
                       },
                       shape: RoundedRectangleBorder(
                           borderRadius: BorderRadius.circular(10)),
@@ -98,18 +101,20 @@ class I_guider extends StatelessWidget {
                     minWidth: 100.0,
                     height: 150.0,
                     child: RaisedButton.icon(
-
                       icon: Icon(
-                        Icons.notifications_active,
+                        Icons.view_stream_outlined,
                         size: 40,
                         color: Colors.white,
                       ),
                       label: Text('',
                           style: TextStyle(fontWeight: FontWeight.bold)),
-                      onPressed: () {},
+                      onPressed: () {
+                      //  action when button is pressed route to heart rate measurer
+                        Navigator.push(context, MaterialPageRoute(builder: (context) => HeartRateScreen() ));
+                      },
                       shape: RoundedRectangleBorder(
                           borderRadius: BorderRadius.circular(10)),
-                      color: Colors.greenAccent,
+                      color: Colors.redAccent,
                     ),
                   ),
                 ),
@@ -140,12 +145,6 @@ class I_guider extends StatelessWidget {
               )
             ],
           ),
-
-
-
-
-
-
         ],
       ),
     );

lib/main.dart

@@ -9,8 +9,8 @@ void main() => runApp(MaterialApp(
   // initialRoute: '/guider',
   routes: {
     '/':(context) => HomeScreen(),
-    '/guider':(context) => I_guider(),
-    '/invoker':(context) => invoker(),
+    // '/guider':(context) => I_guider(),
+    // '/invoker':(context) => invoker(),
 
 
   },

lib/pages/heart_rate/chart.dart

+import 'package:charts_flutter/flutter.dart' as charts;
+import 'package:flutter/material.dart';
+
+class Chart extends StatelessWidget {
+  final List<SensorValue> _data;
+
+  Chart(this._data);
+
+  @override
+  Widget build(BuildContext context) {
+    return new charts.TimeSeriesChart([
+      charts.Series<SensorValue, DateTime>(
+        id: 'Values',
+        colorFn: (_, __) => charts.MaterialPalette.green.shadeDefault,
+        domainFn: (SensorValue values, _) => values.time,
+        measureFn: (SensorValue values, _) => values.value,
+        data: _data,
+      )
+    ],
+        animate: false,
+        primaryMeasureAxis: charts.NumericAxisSpec(
+          tickProviderSpec:
+              charts.BasicNumericTickProviderSpec(zeroBound: false),
+          renderSpec: charts.NoneRenderSpec(),
+        ),
+        domainAxis: new charts.DateTimeAxisSpec(
+            renderSpec: new charts.NoneRenderSpec()));
+  }
+}
+
+class SensorValue {
+  final DateTime time;
+  final double value;
+
+  SensorValue(this.time, this.value);
+}

lib/pages/heart_rate/heart_rate_screen.dart

+import 'package:covidefender/pages/heart_rate/homePage.dart';
+import 'package:flutter/cupertino.dart';
+import 'package:flutter/material.dart';
+
+class HeartRateScreen extends StatelessWidget {
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(
+        title: Text('Heart Rate Detector'),
+      ),
+      body: Column(
+        children: [
+          Padding(
+            padding: const EdgeInsets.all(8.0),
+            child: Image.asset('lib/assets/images/pulse.gif'),
+          ),
+          SizedBox(height: 20),
+          Column(
+            crossAxisAlignment: CrossAxisAlignment.start,
+            children: [
+              ElevatedButton(
+                onPressed: () => Navigator.push(context, MaterialPageRoute(builder: (context) => HomePage(),)),
+                child: Text('Measure Heart Rate'),
+              ),
+            ],
+          ),
+        ],
+      ),
+    );
+  }
+}

lib/pages/heart_rate/homePage.dart

+import 'dart:async';
+
+import 'package:camera/camera.dart';
+import 'package:flutter/material.dart';
+import 'package:wakelock/wakelock.dart';
+import 'chart.dart';
+
+class HomePage extends StatefulWidget {
+  @override
+  HomePageView createState() {
+    return HomePageView();
+  }
+}
+
+class HomePageView extends State<HomePage> with SingleTickerProviderStateMixin {
+  bool _toggled = false; // toggle button value
+  List<SensorValue> _data = List<SensorValue>(); // array to store the values
+  CameraController _controller;
+  double _alpha = 0.3; // factor for the mean value
+  AnimationController _animationController;
+  double _iconScale = 1;
+  int _bpm = 0; // beats per minute
+  int _fs = 30; // sampling frequency (fps)
+  int _windowLen = 30 * 6; // window length to display - 6 seconds
+  CameraImage _image; // store the last camera image
+  double _avg; // store the average value during calculation
+  DateTime _now; // store the now Datetime
+  Timer _timer; // timer for image processing
+
+  @override
+  void initState() {
+    super.initState();
+    _animationController =
+        AnimationController(duration: Duration(milliseconds: 500), vsync: this);
+    _animationController
+      ..addListener(() {
+        setState(() {
+          _iconScale = 1.0 + _animationController.value * 0.4;
+        });
+      });
+  }
+
+  @override
+  void dispose() {
+    _timer?.cancel();
+    _toggled = false;
+    _disposeController();
+    Wakelock.disable();
+    _animationController?.stop();
+    _animationController?.dispose();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      backgroundColor: Colors.white,
+      body: SafeArea(
+        child: Column(
+          children: <Widget>[
+            Expanded(
+                flex: 1,
+                child: Row(
+                  mainAxisAlignment: MainAxisAlignment.spaceBetween,
+                  children: <Widget>[
+                    Expanded(
+                      flex: 1,
+                      child: Padding(
+                        padding: EdgeInsets.all(12),
+                        child: ClipRRect(
+                          borderRadius: BorderRadius.all(
+                            Radius.circular(18),
+                          ),
+                          child: Stack(
+                            fit: StackFit.expand,
+                            alignment: Alignment.center,
+                            children: <Widget>[
+                              _controller != null && _toggled
+                                  ? AspectRatio(
+                                      aspectRatio:
+                                          _controller.value.aspectRatio,
+                                      child: CameraPreview(_controller),
+                                    )
+                                  : Container(
+                                      padding: EdgeInsets.all(12),
+                                      alignment: Alignment.center,
+                                      color: Colors.grey,
+                                    ),
+                              Container(
+                                alignment: Alignment.center,
+                                padding: EdgeInsets.all(4),
+                                child: Text(
+                                  _toggled
+                                      ? "Cover both the camera and the flash with your finger"
+                                      : "Camera feed will display here",
+                                  style: TextStyle(
+                                      backgroundColor: _toggled
+                                          ? Colors.white
+                                          : Colors.transparent),
+                                  textAlign: TextAlign.center,
+                                ),
+                              )
+                            ],
+                          ),
+                        ),
+                      ),
+                    ),
+                    Expanded(
+                      flex: 1,
+                      child: Center(
+                          child: Column(
+                        mainAxisSize: MainAxisSize.min,
+                        crossAxisAlignment: CrossAxisAlignment.center,
+                        children: <Widget>[
+                          Text(
+                            "Estimated BPM",
+                            style: TextStyle(fontSize: 18, color: Colors.grey),
+                          ),
+                          Text(
+                            (_bpm > 30 && _bpm < 150 ? _bpm.toString() : "--"),
+                            style: TextStyle(
+                                fontSize: 32, fontWeight: FontWeight.bold),
+                          ),
+                        ],
+                      )),
+                    ),
+                  ],
+                )),
+            Expanded(
+              flex: 1,
+              child: Center(
+                child: Transform.scale(
+                  scale: _iconScale,
+                  child: IconButton(
+                    icon:
+                        Icon(_toggled ? Icons.favorite : Icons.favorite_border),
+                    color: Colors.red,
+                    iconSize: 128,
+                    onPressed: () {
+                      if (_toggled) {
+                        _untoggle();
+                      } else {
+                        _toggle();
+                      }
+                    },
+                  ),
+                ),
+              ),
+            ),
+            Expanded(
+              flex: 1,
+              child: Container(
+                margin: EdgeInsets.all(12),
+                decoration: BoxDecoration(
+                    borderRadius: BorderRadius.all(
+                      Radius.circular(18),
+                    ),
+                    color: Colors.black),
+                child: Chart(_data),
+              ),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+
+  void _clearData() {
+    // create array of 128 ~= 255/2
+    _data.clear();
+    int now = DateTime.now().millisecondsSinceEpoch;
+    for (int i = 0; i < _windowLen; i++)
+      _data.insert(
+          0,
+          SensorValue(
+              DateTime.fromMillisecondsSinceEpoch(now - i * 1000 ~/ _fs), 128));
+  }
+
+  void _toggle() {
+    _clearData();
+    _initController().then((onValue) {
+      Wakelock.enable();
+      _animationController?.repeat(reverse: true);
+      setState(() {
+        _toggled = true;
+      });
+      // after is toggled
+      _initTimer();
+      _updateBPM();
+    });
+  }
+
+  void _untoggle() {
+    _disposeController();
+    Wakelock.disable();
+    _animationController?.stop();
+    _animationController?.value = 0.0;
+    setState(() {
+      _toggled = false;
+    });
+  }
+
+  void _disposeController() {
+    _controller?.dispose();
+    _controller = null;
+  }
+
+  Future<void> _initController() async {
+    try {
+      List _cameras = await availableCameras();
+      _controller = CameraController(_cameras.first, ResolutionPreset.low);
+      await _controller.initialize();
+      Future.delayed(Duration(milliseconds: 100)).then((onValue) {
+        // _controller.flash(true);
+      });
+      _controller.startImageStream((CameraImage image) {
+        _image = image;
+      });
+    } catch (Exception) {
+      debugPrint(Exception);
+    }
+  }
+
+  void _initTimer() {
+    _timer = Timer.periodic(Duration(milliseconds: 1000 ~/ _fs), (timer) {
+      if (_toggled) {
+        if (_image != null) _scanImage(_image);
+      } else {
+        timer.cancel();
+      }
+    });
+  }
+
+  void _scanImage(CameraImage image) {
+    _now = DateTime.now();
+    _avg =
+        image.planes.first.bytes.reduce((value, element) => value + element) /
+            image.planes.first.bytes.length;
+    if (_data.length >= _windowLen) {
+      _data.removeAt(0);
+    }
+    setState(() {
+      _data.add(SensorValue(_now, _avg));
+    });
+  }
+
+  void _updateBPM() async {
+    // Bear in mind that the method used to calculate the BPM is very rudimentar
+    // feel free to improve it :)
+
+    // Since this function doesn't need to be so "exact" regarding the time it executes,
+    // I only used the a Future.delay to repeat it from time to time.
+    // Ofc you can also use a Timer object to time the callback of this function
+    List<SensorValue> _values;
+    double _avg;
+    int _n;
+    double _m;
+    double _threshold;
+    double _bpm;
+    int _counter;
+    int _previous;
+    while (_toggled) {
+      _values = List.from(_data); // create a copy of the current data array
+      _avg = 0;
+      _n = _values.length;
+      _m = 0;
+      _values.forEach((SensorValue value) {
+        _avg += value.value / _n;
+        if (value.value > _m) _m = value.value;
+      });
+      _threshold = (_m + _avg) / 2;
+      _bpm = 0;
+      _counter = 0;
+      _previous = 0;
+      for (int i = 1; i < _n; i++) {
+        if (_values[i - 1].value < _threshold &&
+            _values[i].value > _threshold) {
+          if (_previous != 0) {
+            _counter++;
+            _bpm += 60 *
+                1000 /
+                (_values[i].time.millisecondsSinceEpoch - _previous);
+          }
+          _previous = _values[i].time.millisecondsSinceEpoch;
+        }
+      }
+      if (_counter > 0) {
+        _bpm = _bpm / _counter;
+        print(_bpm);
+        setState(() {
+          this._bpm = ((1 - _alpha) * this._bpm + _alpha * _bpm).toInt();
+        });
+      }
+      await Future.delayed(Duration(
+          milliseconds:
+              1000 * _windowLen ~/ _fs)); // wait for a new set of _data values
+    }
+  }
+}

lib/pages/mask_detect/invoker.dart

@@ -7,44 +7,37 @@ import 'cameara_service.dart';
 class invoker extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
-return  Scaffold(
-  appBar: AppBar(
-title: Text('Face Mask Detector'),
-
-  ),
-  body: Column(
-    children: [
-      Padding(
-        padding: const EdgeInsets.all(8.0),
-        child: Image.asset('lib/assets/images/wear.gif'),
+    return Scaffold(
+      appBar: AppBar(
+        title: Text('Face Mask Detector'),
       ),
-        SizedBox(height: 20),
-        Column(
-          crossAxisAlignment: CrossAxisAlignment.start,
-          children: [
-            ElevatedButton(
-              onPressed: ()=> invokeCamera(),
-      child: Text('Detect Mask'),
-            ),
-          ],
-        ),
-
-
-
-    ],
-  ),
-
-);
+      body: Column(
+        children: [
+          Padding(
+            padding: const EdgeInsets.all(8.0),
+            child: Image.asset('lib/assets/images/wear.gif'),
+          ),
+          SizedBox(height: 20),
+          Column(
+            crossAxisAlignment: CrossAxisAlignment.start,
+            children: [
+              ElevatedButton(
+                onPressed: () => invokeCamera(),
+                child: Text('Detect Mask'),
+              ),
+            ],
+          ),
+        ],
+      ),
+    );
   }
 
   Future<void> invokeCamera() async {
-      WidgetsFlutterBinding.ensureInitialized();
-  print(await Tflite.loadModel(
-      model: 'lib/assets/model.tflite', labels: "lib/assets/labels.txt"));
-  runApp(MaskDetectingApp(
-    cameras: await availableCameras(),
-  ));
+    WidgetsFlutterBinding.ensureInitialized();
+    print(await Tflite.loadModel(
+        model: 'lib/assets/model.tflite', labels: "lib/assets/labels.txt"));
+    runApp(MaskDetectingApp(
+      cameras: await availableCameras(),
+    ));
   }
-
-
 }

pubspec.yaml

@@ -24,7 +24,7 @@ dependencies:
   flutter:
     sdk: flutter
   flutter_svg: ^0.22.0
-  camera: ^0.5.8+8
+#  camera: ^0.5.8+8
   tflite: ^1.1.1
   oktoast: ^2.3.2
 
@@ -34,6 +34,14 @@ dependencies:
   # Use with the CupertinoIcons class for iOS style icons.
   cupertino_icons: ^1.0.2
 
+  #add dependencies for heart rate module
+  charts_flutter: ^0.9.0
+  wakelock: ^0.1.4+1
+  camera:
+    git:
+      url: http://github.com/indikaNK/plugins.git
+      path: packages/camera/camera
+
 dev_dependencies:
   flutter_test:
     sdk: flutter
@@ -51,6 +59,7 @@ flutter:
 
   assets:
     - lib/assets/images/top_header.jpg
+    - lib/assets/images/hero.gif
     - lib/assets/images/mino.jpg
     - lib/assets/images/boralu.jpg
     - lib/assets/images/map80.png
@@ -59,7 +68,7 @@ flutter:
     - lib/assets/images/coach80.png
     - lib/assets/images/time80.png
     - lib/assets/images/event80.png
-    - lib/assets/images/
+    - lib/assets/images/pulse.gif
     - lib/assets/model.tflite
     - lib/assets/labels.txt
     - assets/