Arduino Nano 33 BLE 不接收通过 flutter 应用程序发送的数据

Question

import 'package:control_pad/control_pad.dart';
import 'package:flutter_reactive_ble/flutter_reactive_ble.dart';

final flutterReactiveBle = FlutterReactiveBle();
late QualifiedCharacteristic c;

Future<void> main() async {
  runApp(const MaterialApp(
    title: 'Control Pad Example',
    home: FirstRoute(),
  ));
}

class FirstRoute extends StatelessWidget {
  const FirstRoute({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('car'),
        actions: [
          IconButton(
            constraints: BoxConstraints.expand(width: 80),
            onPressed: () async {
              print("pressed");
              var serviceUuid =
                  Uuid.parse("0000180a-0000-1000-8000-00805f9b34fb");
              var characteristicUuid =
                  Uuid.parse("00002a57-0000-1000-8000-00805f9b34fb");
              var foundDeviceId = 'FB:DF:BF:CD:83:26';
              flutterReactiveBle.connectToDevice(id: foundDeviceId,
                connectionTimeout: const Duration(seconds: 5),
              ).listen((state) async {
                if (state.connectionState == DeviceConnectionState.connected) {
                  print("connected");
                  await flutterReactiveBle.requestConnectionPriority(deviceId: foundDeviceId, priority:  ConnectionPriority.highPerformance);
                  c = QualifiedCharacteristic(
                      serviceId: serviceUuid,
                      characteristicId: characteristicUuid,
                      deviceId: foundDeviceId);
                }
              });
            },
            icon: const Text("BLE", textAlign: TextAlign.center),
          ),
        ],
      ),
      body: JoystickView(
        onDirectionChanged: (double x, double y) async {
          print('$x, $y');

          flutterReactiveBle.writeCharacteristicWithoutResponse(c, value: [0x01]);
        },
      ),
    );
  }
}

我从 Arduino 收到了连接确认，但是当尝试使用 writeCharacteristicWithoutResponse 时，Arduino 似乎没有收到任何东西。使用像 LightBlue 这样的应用程序，我可以轻松地编写十六进制输入，而 Arduino 会接收它们。我对蓝牙没有太多先验知识，想了解我在这里缺少的是什么。 Arduino 代码似乎运行良好，所以问题出在 flutter 应用程序方面。

Answer 1

我无法让代码与我正在使用的包一起工作。改成Flutter Blue并使用这段代码后，我在flutter应用程序中写入和接收数据成功。

async {
  flutterBlue.startScan(timeout: Duration(seconds: 4));
  var subscription =
      flutterBlue.scanResults.listen((results) async {
    for (int k = 0; k < results.length; k++) {
      ScanResult r = results[k];
      if (r.device.id.toString() == <YOUR_DEVICE_ID>) {
        print("found device");
        device = r.device;
        await device.connect();
        List<BluetoothService> services =
            await device.discoverServices();
        for (int j = 0; j < services.length; j++) {
          var service = services[j];
          if (service.uuid.toString() ==
              <YOUR_SERVICE_UUID>) {
            print("found serial");
            var characteristics = service.characteristics;
            for (int i = 0; i < characteristics.length; i++) {
              BluetoothCharacteristic c = characteristics[i];
              if (c.uuid.toString() ==
                  <YOUR_CHARACTERISTIC_UUID>) {
                print("found chars");
                chars = c;
              }
            }
          }
        }
      }
    }
  });
}

这是一个可用但有问题的特征查找器。在此之后，您可以使用简单的 await chars.write([<hex-value>]); 发送数据。如果没有打开响应（它们是自动的），这是行不通的。如果有人能解释一下，那就太好了。

Arduino Nano 33 BLE 不接收通过 flutter 应用程序发送的数据

Arduino Nano 33 BLE doesn't receive data sent via flutter app

flutter

arduino

bluetooth

bluetooth-lowenergy

arduino-nano