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BLE中心模式流程

BLE中心模式流程

作者: Z了个L | 来源:发表于2016-08-21 19:46 被阅读368次

    BLE中心模式流程

    • 1.建立中心角色
    • 2.扫描外设(Discover Peripheral)
    • 3.连接外设(Connect Peripheral)
    • 4.扫描外设中的服务和特征(Discover Services And Characteristics)
      • 4.1 获取外设的services
      • 4.2 获取外设的Characteristics,获取characteristics的值,,获取Characteristics的Descriptor和Descriptor的值
    • 5.利用特征与外设做数据交互(Explore And Interact)
    • 6.订阅Characteristic的通知
    • 7.断开连接(Disconnect)

    准备环境

    • 1.Xcode7.0
    • 2.手机
    • 3.外设(手机+LightBlue)

    实现步骤

    1.导入CB头文件,建立主设备管理类,设置主设备代理

    #import <CoreBluetooth/CoreBluetooth.h>
    @interface XMGBLEController () <CBCentralManagerDelegate>
    @property (nonatomic, strong) CBCentralManager *cMgr; /**< 中心管理设备 */
    @end
    @implementation XMGBLEController
    #pragma mark - 懒加载
    // 1.建立中心管理者
    - (CBCentralManager *)cMgr
    {
        if (!_cMgr) {
            NSLog(@"%s, line = %d", __FUNCTION__, __LINE__);
            /*
             设置主设备的代理,CBCentralManagerDelegate
             必须实现的:
             - (void)centralManagerDidUpdateState:(CBCentralManager *)central;//主设备状态改变调用,在初始化CBCentralManager的适合会打开设备,只有当设备正确打开后才能使用
             其他选择实现的委托中比较重要的:
             - (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI; //找到外设
             - (void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral;//连接外设成功
             - (void)centralManager:(CBCentralManager *)central didFailToConnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error;//外设连接失败
             - (void)centralManager:(CBCentralManager *)central didDisconnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error;//断开外设
             */
            _cMgr = [[CBCentralManager alloc] initWithDelegate:self queue:dispatch_get_main_queue()]; // 线程不传默认是主线程
        }
        return _cMgr;
    }
    - (void)viewDidLoad {
        [super viewDidLoad];
        self.title = @"BLE";
        self.view.backgroundColor = [UIColor orangeColor];
        // 初始化
        [self cMgr];
        // 不能在此处扫描,因为状态还没变为打开
        //[self.cMgr scanForPeripheralsWithServices:nil options:nil];
    }
    

    2.扫描外设

    • 扫描的方法防治cMgr成功打开的代理方法中
    • 只有设备成功打开,才能开始扫描,否则会报错
    #pragma mark - CBCentralManagerDelegate
    // 中心管理者状态改变, 在初始化CBCentralManager的时候会打开设备,只有当设备正确打开后才能使用
    - (void)centralManagerDidUpdateState:(CBCentralManager *)central
    {
        NSLog(@"%s, line = %d", __FUNCTION__, __LINE__);
        switch (central.state) {
            case CBCentralManagerStateUnknown:
                NSLog(@">>>CBCentralManagerStateUnknown");
                break;
            case CBCentralManagerStateResetting:
                NSLog(@">>>CBCentralManagerStateResetting");
                break;
            case CBCentralManagerStateUnsupported:
                NSLog(@">>>CBCentralManagerStateUnsupported");
                break;
            case CBCentralManagerStateUnauthorized:
                NSLog(@">>>CBCentralManagerStateUnauthorized");
                break;
            case CBCentralManagerStatePoweredOff:
                NSLog(@">>>CBCentralManagerStatePoweredOff");
                break;
            case CBCentralManagerStatePoweredOn:
                NSLog(@">>>CBCentralManagerStatePoweredOn");
                // 2.开始扫描周围的外设
                /*
                 第一个参数nil就是扫描周围所有的外设,扫描到外设后会进入
                 - (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI;
                 */
                [self.cMgr scanForPeripheralsWithServices:nil options:nil];
    
                break;
            default:
            break;
        }
    }
    // 扫描到设备会进入到此代理方法
    - (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary<NSString *,id> *)advertisementData RSSI:(NSNumber *)RSSI
    {
        NSLog(@"%s, line = %d, per = %@, data = %@, rssi = %@", __FUNCTION__, __LINE__, peripheral, advertisementData, RSSI);
        // 接下来连接设备
    }
    
    

    3.连接外设

    • 扫描手环,打印结果
    • 根据打印结果
    // 扫描到设备会进入到此代理方法
    - (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary<NSString *,id> *)advertisementData RSSI:(NSNumber *)RSSI
    {
        NSLog(@"%s, line = %d, per = %@, data = %@, rssi = %@", __FUNCTION__, __LINE__, peripheral, advertisementData, RSSI);
    
        // 3.接下来可以连接设备
        //如果你没有设备,可以下载一个app叫lightbule的app去模拟一个设备
        //这里自己去设置下连接规则,我设置的是二维码扫描到的运动手环的设备号
        // 判断设备号是否扫描到
        if ([peripheral.name isEqualToString:@"OBand-75"]) {
            /*
             一个主设备最多能连7个外设,每个外设最多只能给一个主设备连接,连接成功,失败,断开会进入各自的委托
             - (void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral;//连接外设成功的委托
             - (void)centralManager:(CBCentralManager *)central didFailToConnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error;//外设连接失败的委托
             - (void)centralManager:(CBCentralManager *)central didDisconnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error;//断开外设的委托
             */
            // 保存外设,否则方法结束就销毁
            self.per = peripheral;
            [self.cMgr connectPeripheral:self.per options:nil];
        }else
        {
            // 此处Alert提示未扫描到设备,重新扫描
    #warning noCode
            NSLog(@"没扫描到 >>>>>>>>  %s, line = %d", __FUNCTION__, __LINE__);
        }
    }
    // 外设连接成功
    - (void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral
    {
        NSLog(@"%s, line = %d", __FUNCTION__, __LINE__);
        NSLog(@">>>连接到名称为(%@)的设备-成功",peripheral.name);
    }
    // 外设连接失败
    - (void)centralManager:(CBCentralManager *)central didFailToConnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error
    {
        NSLog(@"%s, line = %d", __FUNCTION__, __LINE__);
    }
    // 断开连接(丢失连接)
    - (void)centralManager:(CBCentralManager *)central didDisconnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error
    {
        NSLog(@"%s, line = %d", __FUNCTION__, __LINE__);
    }
    

    4.扫描外设中的服务和特征

      设备链接成功后,就可以扫描设备的服务(services)了,同样是通过代理,扫描到结果后会触发某代理方法.
      注意:此时CBCentralManagerDelegate已经不能满足需求,需要新的CBPeripheralDelegate来搞定.
      该协议中包含了central与peripheral的许多回调方法
      (eg.:获取services,获取characteristics,获取characteristics的值,获取characteristics的Descriptor以及Descriptor的值,写数据,读RSSI,用通知的方式订阅数据等等).
    
    
    • 4.1 获取外设的services
      • 首先设置外设的代理,并搜寻services
      • 然后在代理方法peripheral:didDiscoverServices:中遍历services
    // 外设连接成功
    - (void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral
    {
        NSLog(@"%s, line = %d", __FUNCTION__, __LINE__);
        NSLog(@">>>连接到名称为(%@)的设备-成功",peripheral.name);
        //设置的peripheral代理CBPeripheralDelegate
        //@interface ViewController : UIViewController<CBCentralManagerDelegate,CBPeripheralDelegate>
        [peripheral setDelegate:self];
    
        //扫描外设Services,成功后会进入方法:-(void)peripheral:(CBPeripheral *)peripheral didDiscoverServices:(NSError *)error{
        [peripheral discoverServices:nil];
        /*
         Discovers the specified services of the peripheral.
         An array of CBUUID objects that you are interested in. Here, each CBUUID object represents a UUID that identifies the type of service you want to discover.
         */
    }
    
    #pragma mark - CBPeripheralDelegate
    // 发现外设的service
    - (void)peripheral:(CBPeripheral *)peripheral didDiscoverServices:(NSError *)error
    {
        if (error)
        {
            NSLog(@">>>Discovered services for %@ with error: %@", peripheral.name, [error localizedDescription]);
            return;
        }
    
        for (CBService *service in peripheral.services) {
            NSLog(@"service.UUID = %@", service.UUID);
            //扫描每个service的Characteristics,扫描到后会进入方法: -(void)peripheral:(CBPeripheral *)peripheral didDiscoverCharacteristicsForService:(CBService *)service error:(NSError *)error
            [peripheral discoverCharacteristics:nil forService:service];
        }
    }
    
    • 4.2 获取外设的characteris,获取Characteristics的值,获取Characteristics的Descriptor以及Descriptor的值
    // 外设发现service的特征
    - (void)peripheral:(CBPeripheral *)peripheral didDiscoverCharacteristicsForService:(CBService *)service error:(NSError *)error
    {
        if (error)
        {
            NSLog(@"error Discovered characteristics for %@ with error: %@", service.UUID, [error localizedDescription]);
            return;
        }
        for (CBCharacteristic *characteristic in service.characteristics)
        {
            NSLog(@"service:%@ 的 Characteristic: %@",service.UUID,characteristic.UUID);
        }
    
    #warning noCodeFor 优化,分开写是为了让大家看注释清晰,并不符合编码规范
        //获取Characteristic的值,读到数据会进入方法:-(void)peripheral:(CBPeripheral *)peripheral didUpdateValueForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error
        for (CBCharacteristic *characteristic in service.characteristics){
            [peripheral readValueForCharacteristic:characteristic]; // 外设读取特征的值
        }
    
        //搜索Characteristic的Descriptors,读到数据会进入方法:-(void)peripheral:(CBPeripheral *)peripheral didDiscoverDescriptorsForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error
        for (CBCharacteristic *characteristic in service.characteristics){
            [peripheral discoverDescriptorsForCharacteristic:characteristic]; // 外设发现特征的描述
        }
    }
    
    // 获取characteristic的值
    - (void)peripheral:(CBPeripheral *)peripheral didUpdateValueForCharacteristic:(nonnull CBCharacteristic *)characteristic error:(nullable NSError *)error
    {
        //打印出characteristic的UUID和值
        //!注意,value的类型是NSData,具体开发时,会根据外设协议制定的方式去解析数据
        NSLog(@"%s, line = %d, characteristic.UUID:%@  value:%@", __FUNCTION__, __LINE__, characteristic.UUID, characteristic.value);
    }
    // 获取Characteristics的 descriptor的值
    - (void)peripheral:(CBPeripheral *)peripheral didUpdateValueForDescriptor:(nonnull CBDescriptor *)descriptor error:(nullable NSError *)error
    {
        //打印出DescriptorsUUID 和value
        //这个descriptor都是对于characteristic的描述,一般都是字符串,所以这里我们转换成字符串去解析
        NSLog(@"%s, line = %d, descriptor.UUID:%@ value:%@", __FUNCTION__, __LINE__, descriptor.UUID, descriptor.value);
    }
    // 发现特征Characteristics的描述Descriptor
    - (void)peripheral:(CBPeripheral *)peripheral didDiscoverDescriptorsForCharacteristic:(nonnull CBCharacteristic *)characteristic error:(nullable NSError *)error
    {
        NSLog(@"%s, line = %d", __FUNCTION__, __LINE__);
        for (CBDescriptor *descriptor in characteristic.descriptors) {
            NSLog(@"descriptor.UUID:%@",descriptor.UUID);
        }
    }
    

    5.写数据到特征中

    // 5.将数据写入特征(自定义方法,为了看的更清楚,没别的意思)
    - (void)yf_peripheral:(CBPeripheral *)peripheral writeData:(NSData *)data forCharacteristic:(CBCharacteristic *)characteristic
    {
        /*
        typedef NS_OPTIONS(NSUInteger, CBCharacteristicProperties) {
            CBCharacteristicPropertyBroadcast                                               = 0x01,
            CBCharacteristicPropertyRead                                                    = 0x02,
            CBCharacteristicPropertyWriteWithoutResponse                                    = 0x04,
            CBCharacteristicPropertyWrite                                                   = 0x08,
            CBCharacteristicPropertyNotify                                                  = 0x10,
            CBCharacteristicPropertyIndicate                                                = 0x20,
            CBCharacteristicPropertyAuthenticatedSignedWrites                               = 0x40,
            CBCharacteristicPropertyExtendedProperties                                      = 0x80,
            CBCharacteristicPropertyNotifyEncryptionRequired NS_ENUM_AVAILABLE(NA, 6_0)     = 0x100,
            CBCharacteristicPropertyIndicateEncryptionRequired NS_ENUM_AVAILABLE(NA, 6_0)   = 0x200
        };
         打印出特征的权限(characteristic.properties),可以看到有很多种,这是一个NS_OPTIONS的枚举,可以是多个值
         常见的又read,write,noitfy,indicate.知道这几个基本够用了,前俩是读写权限,后俩都是通知,俩不同的通知方式
         */
        NSLog(@"%s, line = %d, characteristic.properties:%d", __FUNCTION__, __LINE__, characteristic.properties);
    
        // 只有特征的properties中有写的属性时候,才写
        if (characteristic.properties & CBCharacteristicPropertyWrite) {
            // 这句才是正宗的核心代码
            [peripheral writeValue:data forCharacteristic:characteristic type:CBCharacteristicWriteWithResponse];
        }
    }
    

    6.订阅特征的通知

    // 设置通知
    - (void)yf_peripheral:(CBPeripheral *)peripheral setNotifyForCharacteristic:(CBCharacteristic *)characteristic
    {
        // 设置通知, 数据会进入 peripheral:didUpdateValueForCharacteristic:error:方法
        [peripheral setNotifyValue:YES forCharacteristic:characteristic];
    }
    // 取消通知
    - (void)yf_peripheral:(CBPeripheral *)peripheral cancelNotifyForCharacteristic:(CBCharacteristic *)characteristic
    {
        [peripheral setNotifyValue:NO forCharacteristic:characteristic];
    }
    

    7.断开连接

    // 7.断开连接
    - (void)yf_cMgr:(CBCentralManager *)cMgr stopScanAndDisConnectWithPeripheral:(CBPeripheral *)peripheral
    {
        // 停止扫描
        [cMgr stopScan];
        // 断开连接
        [cMgr cancelPeripheralConnection:peripheral];
    }
    

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