做淘客的网站名称南京广告宣传公司seo
要使用 Dart 实现与蓝牙设备的通信,需要按照以下步骤进行。以下是详细的实现思路和代码示例:
1. 理解蓝牙协议
从提供的表格中可以看到,该蓝牙协议包含以下关键部分:
- 包头:
0x59 0x59
- 包长:
0x06
(表示数据包长度) - 功能项:
0x0a
(标识功能类别) - 功能参数:具体的功能指令(如
01
、02
等) - 校验和:
ADD8
校验和(通常是对数据包内容的累加校验)
协议要点
-
包结构:
- 固定包头:
0x59 0x59
- 包长:
0x06
(固定值) - 功能项:
0x0a
- 功能参数:根据功能需求动态变化
- 校验和:对包头、包长、功能项和功能参数的累加校验
- 固定包头:
-
校验和计算规则:
- 将包头、包长、功能项和功能参数的所有字节相加,取低 8 位作为校验和。
2. Dart 中的蓝牙通信
Dart 提供了 flutter_blue
插件,用于实现蓝牙通信。以下是实现步骤:
步骤 1:添加依赖
在 pubspec.yaml
文件中添加 flutter_blue
依赖:
dependencies:flutter_blue: ^latest_version
步骤 2:初始化蓝牙模块
在应用中初始化蓝牙模块,并扫描设备:
import 'package:flutter_blue/flutter_blue.dart';FlutterBlue flutterBlue = FlutterBlue.instance;// 扫描蓝牙设备
Future<void> scanDevices() async {await flutterBlue.startScan(timeout: Duration(seconds: 4));List<BluetoothDevice> devices = [];flutterBlue.scanResults.listen((results) {for (var r in results) {if (!devices.contains(r.device)) {devices.add(r.device);print('Found device: ${r.device.name} - ${r.device.id}');}}});
}
步骤 3:连接蓝牙设备
找到目标设备后,连接到设备并获取服务和特征:
Future<void> connectToDevice(BluetoothDevice device) async {try {await device.connect();print('Connected to device: ${device.name}');// 获取服务List<BluetoothService> services = await device.discoverServices();for (var service in services) {print('Service UUID: ${service.uuid.toString()}');for (var characteristic in service.characteristics) {print('Characteristic UUID: ${characteristic.uuid.toString()}');}}} catch (e) {print('Failed to connect: $e');}
}
步骤 4:发送数据
根据协议构造数据包,并通过特征写入数据:
void sendData(BluetoothCharacteristic characteristic, int functionCode, int parameter) {// 构造数据包List<int> packet = [0x59, 0x59, // 包头0x06, // 包长0x0a, // 功能项functionCode, // 功能码parameter, // 参数calculateChecksum([0x59, 0x59, 0x06, 0x0a, functionCode, parameter]) // 校验和];// 发送数据characteristic.write(packet).then((_) {print('Data sent successfully: $packet');}).catchError((error) {print('Failed to send data: $error');});
}int calculateChecksum(List<int> data) {int checksum = 0;for (var byte in data) {checksum += byte;}return checksum & 0xFF; // 取低 8 位
}
步骤 5:接收数据
如果设备有反馈,可以通过监听特征值的变化来接收数据:
void listenForData(BluetoothCharacteristic characteristic) {characteristic.value.listen((data) {print('Received data: $data');// 解析接收到的数据});
}
3. 示例代码
以下是完整的示例代码,展示如何连接蓝牙设备并发送指令:
import 'package:flutter/material.dart';
import 'package:flutter_blue/flutter_blue.dart';void main() {runApp(MyApp());
}class MyApp extends StatelessWidget { Widget build(BuildContext context) {return MaterialApp(home: BluetoothApp(),);}
}class BluetoothApp extends StatefulWidget { _BluetoothAppState createState() => _BluetoothAppState();
}class _BluetoothAppState extends State<BluetoothApp> {FlutterBlue flutterBlue = FlutterBlue.instance;BluetoothDevice? connectedDevice;BluetoothCharacteristic? writeCharacteristic;void initState() {super.initState();initBluetooth();}Future<void> initBluetooth() async {await flutterBlue.initialize();scanDevices();}Future<void> scanDevices() async {await flutterBlue.startScan(timeout: Duration(seconds: 4));flutterBlue.scanResults.listen((results) {for (var r in results) {print('Found device: ${r.device.name} - ${r.device.id}');connectToDevice(r.device);}});}Future<void> connectToDevice(BluetoothDevice device) async {try {await device.connect();setState(() {connectedDevice = device;});// 获取服务和特征List<BluetoothService> services = await device.discoverServices();for (var service in services) {for (var characteristic in service.characteristics) {if (characteristic.properties.write) {writeCharacteristic = characteristic;break;}}}if (writeCharacteristic != null) {print('Found writable characteristic: ${writeCharacteristic!.uuid}');}} catch (e) {print('Failed to connect: $e');}}void sendData(int functionCode, int parameter) {if (writeCharacteristic == null) return;List<int> packet = [0x59, 0x59, // 包头0x06, // 包长0x0a, // 功能项functionCode, // 功能码parameter, // 参数calculateChecksum([0x59, 0x59, 0x06, 0x0a, functionCode, parameter]) // 校验和];writeCharacteristic!.write(packet).then((_) {print('Sent data: $packet');}).catchError((error) {print('Failed to send data: $error');});}int calculateChecksum(List<int> data) {int checksum = 0;for (var byte in data) {checksum += byte;}return checksum & 0xFF; // 取低 8 位} Widget build(BuildContext context) {return Scaffold(appBar: AppBar(title: Text('Bluetooth App')),body: Center(child: Column(mainAxisAlignment: MainAxisAlignment.center,children: [ElevatedButton(onPressed: () => sendData(0x01, 0x00), // 按摩椅开机child: Text('开机'),),ElevatedButton(onPressed: () => sendData(0x02, 0x00), // 开关机child: Text('开关机'),),ElevatedButton(onPressed: () => sendData(0x00, 0x00), // 按摩开始child: Text('按摩开始'),),],),),);}
}
4. 注意事项
-
权限管理:
- 在 Android 和 iOS 上,确保申请了蓝牙相关的权限。
- Android 需要在
AndroidManifest.xml
中声明蓝牙权限:<uses-permission android:name="android.permission.BLUETOOTH" /> <uses-permission android:name="android.permission.BLUETOOTH_ADMIN" /> <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
-
设备兼容性:
- 不同设备的蓝牙服务和特征可能不同,需要根据实际设备调整服务和特征的 UUID。
-
错误处理:
- 蓝牙通信可能会出现超时或连接失败的情况,需要做好异常捕获和重试机制。
-
校验和验证:
- 确保校验和的计算逻辑与设备端一致,避免因校验和错误导致通信失败。
5. 总结
通过上述步骤,您可以使用 Dart 和 flutter_blue
插件实现与蓝牙设备的通信,并根据提供的协议发送和接收数据。关键在于正确解析协议格式,并确保数据包的完整性(包括校验和)。