Блог

Я использую BLE esp32 для получения данных с датчиков, но когда я хочу выполнить калибровку, получив данные с устройства BLE, это выдает мне эту ошибку в построителе потоков, который я использовал на экране настройки устройства. A Как только я нажимаю «Конфигурация», он переходит на страницу настройки устройства. Я хочу, чтобы до тех пор, пока я не получу значение 1 от BLE, он продолжал показывать этот экран

and once 1 comes it should go to the other screen to show a message and picture done like this and then automatically moves to Homepage after 2 seconds.

But it shows the bottom overflowed with the error msg «Bluetooth is not active», how can I avoid that? and jump for the next page? BLE is active as well since I checked the values were coming on another screen, but it is not happening on this screen for the connected device. Also the device done page it is not even going to Homescreen
I am new to FLutter that’s why i have no idea what i should do with it.

Code for Device Set up Screen:

 import 'dart:typed_data';

import 'package:epicare/ConfDeviceDone.dart';
import 'package:epicare/ConfigurationScreen.dart';
import 'package:flutter/material.dart';
import 'package:flutter_blue/flutter_blue.dart';
import 'package:flutter_spinkit/flutter_spinkit.dart';
import 'package:fluttertoast/fluttertoast.dart';

import 'Homepage.dart';

class ConfDeviceSet extends StatefulWidget {
  const ConfDeviceSet({Key key, this.device}) : super(key: key);
  final BluetoothDevice device;
  @override
  _ConfDeviceSetState createState() => _ConfDeviceSetState();
}

class _ConfDeviceSetState extends State<ConfDeviceSet> {
  // BLE
  final String SERVICE_UUID = "4fafc201-1fb5-459e-8fcc-c5c9c331914b";
  //final String SERVICE_UUID = "0365a300-8d69-4066-80c7-554298a6ec5e";
  //final String CHARACTERISTIC_UUID = "cf01c075-cb75-4dea-819e-2a79dd466bcb";
  final String CHARACTERISTIC_UUID = "beb5483e-36e1-4688-b7f5-ea07361b26a8";
  bool isReady;
  Stream<List<int>> stream;
  List<int> lastValue;
  List<double> traceDust = List();
  @override
  void initState() {
    isReady = false;
    discoverServices();
  }

  discoverServices() async {
    List<BluetoothService> services = await widget.device.discoverServices();
    services.forEach((service) {
      if (service.uuid.toString() == SERVICE_UUID) {
        service.characteristics.forEach((characteristic) {
          if (characteristic.uuid.toString() == CHARACTERISTIC_UUID) {
            characteristic.setNotifyValue(!characteristic.isNotifying);
            stream = characteristic.value;
            //print(stream);
            lastValue = characteristic.lastValue;
            //print(lastValue);

            setState(() {
              isReady = true;
            });
          }
        });
      }
    });
  }

  _dataParser(List<int> data) {
    var value = Uint8List.fromList(data);
    print("stream.value: $value"); // stream.value: [33]
    var hr = ByteData.sublistView(value, 0, 1);
    print("Heart rate: ${hr.getUint8(0)}");
    return hr.getUint8(0); // Heart rate: 33
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: Colors.white,
      appBar: AppBar(
        backgroundColor: const Color(0xffE5E0A1),
        elevation: 0,
        centerTitle: true,
        title: Text(
          "Configuration",
          style: TextStyle(
            fontSize: 15.0,
            color: Colors.black,
            fontFamily: 'Montserrat',
            fontWeight: FontWeight.normal,
          ),
        ),
        leading: IconButton(
          icon: Icon(
            Icons.arrow_back,
            color: Colors.black,
          ),
          onPressed: () {
            Navigator.push(
              context,
              MaterialPageRoute(
                builder: (context) {
                  return ConfigurationScreen();
                },
              ),
            );
          },
        ),
      ),
      body: Column(
        children: [
          Container(
            padding: EdgeInsets.only(top: 65),
            alignment: Alignment.center,
            child: Text(
              'Device setting up...',
              style: TextStyle(
                fontFamily: 'Montserrat',
                fontWeight: FontWeight.w600,
                fontSize: 17,
                color: const Color(0xa8000000),
                height: 1.3333333333333333,
              ),
              textHeightBehavior:
                  TextHeightBehavior(applyHeightToFirstAscent: false),
              textAlign: TextAlign.center,
            ),
          ),
          Container(
            padding: EdgeInsets.symmetric(vertical: 120),
            child: const SpinKitFadingCircle(
              color: const Color(0xffF1C40E),
              size: 200,
            ),
          ),
          StreamBuilder<List<int>>(
            stream: stream,
            initialData: lastValue,
            builder: (BuildContext context, AsyncSnapshot<List<int>> snapshot) {
              var currentValue = _dataParser(snapshot.data);
              if (currentValue == 1) {
                print("Test Conf 1");
                Navigator.push(
                  context,
                  MaterialPageRoute(
                    builder: (context) {
                      return ConfDeviceDone(
                        device: widget.device,
                      );
                    },
                  ),
                );
              }
            },
          ),
        ],
      ),
    );
  }
}
 

Код для экрана «Готово» устройства

 import 'package:epicare/Homepage.dart';
import 'package:flutter/material.dart';
import 'package:flutter_blue/flutter_blue.dart';

import 'ConfigurationScreen.dart';

class ConfDeviceDone extends StatefulWidget {
  const ConfDeviceDone({Key key, this.device}) : super(key: key);
  final BluetoothDevice device;
  @override
  _ConfDeviceDoneState createState() => _ConfDeviceDoneState();
}

class _ConfDeviceDoneState extends State<ConfDeviceDone> {
  @override
  void initState() {
    // isReady = false;
    // discoverServices();
    var d = Duration(seconds: 2);
    // delayed 5 seconds to next page
    Future.delayed(d, () {
      // to next page and close this page
      Navigator.pushAndRemoveUntil(
        context,
        MaterialPageRoute(
          builder: (context) {
            return Homepage(device: widget.device);
          },
        ),
            (route) => false,
      );
    });

    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: Colors.white,
      appBar: AppBar(
        backgroundColor: const Color(0xffE5E0A1),
        elevation: 0,
        centerTitle: true,
        title: Text(
          "Configuration",
          style: TextStyle(
            fontSize: 15.0,
            color: Colors.black,
            fontFamily: 'Montserrat',
            fontWeight: FontWeight.normal,
          ),
        ),
      ),
      body: Column(
        children: [
          Container(
            padding: EdgeInsets.only(top: 65),
            alignment: Alignment.center,
            child: Text(
              'Device Configured Successfully!',
              style: TextStyle(
                fontFamily: 'Montserrat',
                fontWeight: FontWeight.w600,
                fontSize: 15,
                color: const Color(0xa8000000),
                height: 1.3333333333333333,
              ),
              textHeightBehavior:
                  TextHeightBehavior(applyHeightToFirstAscent: false),
              textAlign: TextAlign.center,
            ),
          ),
          Container(
            padding: EdgeInsets.symmetric(vertical: 120),
            child: Image.asset('assets/images/green-tick.gif'),
          ),
        ],
      ),
    );
  }
}