蓝牙(一)iOS关于蓝牙的使用

简介

开发使用的框架是CoreBluetooth框架,CoreBluetooth是基于BLE4.0的标准的。什么是BLE呢?全称是 buletouch low energy,就是蓝牙低能耗技术。在没有开发蓝牙4.0技术的时候,iOS设备要想开发一个根硬件通讯功能的话,必须通过苹果的mfi认证,否则是不被允许与其他硬件进行连接的,mfi全称是 make for ipad ,iphone, itouch ,是专门为苹果设备制作的设备。注意,iOS设备支持BLE4.0是从iPhone4s开始的(不包括iPhone4s)。

业务逻辑、角色、内容

业务角色

主要分为两个部分
(1)central:中央设备,又叫做中央角色,搜索可以连接的外设,然后请求连接,请求通过后就可以交换数据了。使用的是外围设备的数据,可以写入数据到外围设备
(2)peripheral:外围设备,(下边我都称为外设)又叫做周边设备,用来广播数据的设备,告诉外部这有数据,并且说明了能提供的服务,外围设备可以发送数据到中央设备


蓝牙(一)iOS关于蓝牙的使用_第1张图片
Paste_Image.png

数据结构:外围设备会发送服务(Service),一个服务里面又包含多个特征,特征就是具体键值对,提供数据的地方。每个特征属性分为这么几种:读,写,通知这么几种方式。同时,一个外围设备在广播服务的时候,可以同时发送多个服务。

蓝牙(一)iOS关于蓝牙的使用_第2张图片
Paste_Image.png

工作流程

(1)外设发布服务
(2)中央搜索外设
(3)连接外设
(4)获得服务以及每个服务的特征
(5)获得特征中的值

方法属性介绍

CBCentralManager是中央设备的管理者,一个项目中最好只有一个中央设备管理者,因此在项目中尽量用单例去初始化。

@interface ViewController : UIViewController
 @interface ViewController ()
{ 
 CBCentralManager *manager; //系统蓝牙设备管理对象,可以把他理解为主设备,通过他,可以去扫描和链接外设
NSMutableArray *peripherals; //用于保存被发现设备
 }

具体实现步骤代码:
1 导入CoreBluetooth头文件,建立主设备管理类,设置主设备委托

 #import  
@interface ViewController : UIViewController 
@interface ViewController (){
  CBCentralManager *manager; //系统蓝牙设备管理对象,可以把他理解为主设备,通过他,可以去扫描和链接外设
NSMutableArray *peripherals; //用于保存被发现设备
 } - (void)viewDidLoad { [super viewDidLoad];
 /* 设置主设备的委托,CBCentralManagerDelegate 必须实现的:
 
//主设备状态改变的委托,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)centralManagerDidUpdateState:(CBCentralManager *)central;

//找到外设的委托 
 - (void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI;

 //连接外设成功的委托
- (void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral;

//外设连接失败的委托
 - (void)centralManager:(CBCentralManager *)central didFailToConnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error;

//断开外设的委托
 - (void)centralManager:(CBCentralManager *)central didDisconnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error;
 */ 
//初始化并设置委托和线程队列,最好一个线程的参数可以为nil,默认会就main线程 manager = [[CBCentralManager alloc]initWithDelegate:self queue:dispatch_get_main_queue()];

2 扫描外设(discover),扫描外设的方法我们放在centralManager成功打开的委托中,因为只有设备成功打开,才能开始扫描,否则会报错

 -(void)centralManagerDidUpdateState:(CBCentralManager *)central{ 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"); //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;
 */
 [manager scanForPeripheralsWithServices:nil options:nil]; 
break; 
default: break;
 } } 
//扫描到设备会进入方法
 -(void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI{ 

NSLog(@"当扫描到设备:%@",peripheral.name); //接下来可以连接设备

 }

3 连接外设(connect)

 //扫描到设备会进入方法
 -(void)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI{
 //接下连接我们的测试设备,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P开头的设备
 if ([peripheral.name hasPrefix:@"P"])
{ 
/*
 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 
//连接外设成功的委托
- (void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral;

//外设连接失败的委托 
- (void)centralManager:(CBCentralManager *)central didFailToConnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error;

//断开外设的委托
 - (void)centralManager:(CBCentralManager *)central didDisconnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error;
 */
 //找到的设备必须持有它,否则CBCentralManager中也不会保存peripheral,那么CBPeripheralDelegate中的方法也不会被调用!! [peripherals addObject:peripheral];

 //连接设备
 [manager connectPeripheral:peripheral options:nil];
 }
 } 

//连接到Peripherals-成功
 - (void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral {
 NSLog(@">>>连接到名称为(%@)的设备-成功",peripheral.name); 
}

 //连接到Peripherals-失败
 -(void)centralManager:(CBCentralManager *)central didFailToConnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error { 
NSLog(@">>>连接到名称为(%@)的设备-失败,原因:%@",[peripheral name],[error localizedDescription]);
 } 

//Peripherals断开连接
 - (void)centralManager:(CBCentralManager *)central didDisconnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error{
 NSLog(@">>>外设连接断开连接 %@: %@\n", [peripheral name], [error localizedDescription]); 
}

4扫描外设中的服务和特征(discover)
设备连接成功后,就可以扫描设备的服务了,同样是通过委托形式,扫描到结果后会进入委托方法。但是这个委托已经不再是主设备的委托(CBCentralManagerDelegate),而是外设的委托(CBPeripheralDelegate),这个委托包含了主设备与外设交互的许多 回叫方法,包括获取services,获取characteristics,获取characteristics的值,获取characteristics的Descriptor,和Descriptor的值,写数据,读rssi,用通知的方式订阅数据等等。
获取外设的services

 //连接到Peripherals-成功
 - (void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral {
 NSLog(@">>>连接到名称为(%@)的设备-成功",peripheral.name);
 //设置的peripheral委托CBPeripheralDelegate 
//@interface ViewController : UIViewController [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];
 } 

//扫描到Services
 -(void)peripheral:(CBPeripheral *)peripheral didDiscoverServices:(NSError *)error{
 // NSLog(@">>>扫描到服务:%@",peripheral.services);
 if (error) { 
NSLog(@">>>Discovered services for %@ with error: %@", peripheral.name, [error localizedDescription]); 
return;
 } 
for (CBService *service in peripheral.services) { NSLog(@"%@",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];
 }
 }

获取外设的Characteristics,获取Characteristics的值,获取Characteristics的Descriptor和Descriptor的值

     //扫描到Characteristics
     -(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);
         }

         //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];
             }
         }

         //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];
         }


     }

    //获取的charateristic的值
    -(void)peripheral:(CBPeripheral *)peripheral didUpdateValueForCharacteristic:(CBCharacteristic *)characteristic error:(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(@"characteristic uuid:%@  value:%@",characteristic.UUID,characteristic.value);

    }

    //搜索到Characteristic的Descriptors
    -(void)peripheral:(CBPeripheral *)peripheral didDiscoverDescriptorsForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error{

        //打印出Characteristic和他的Descriptors
         NSLog(@"characteristic uuid:%@",characteristic.UUID);
        for (CBDescriptor *d in characteristic.descriptors) {
            NSLog(@"Descriptor uuid:%@",d.UUID);
        }

    }
    //获取到Descriptors的值
    -(void)peripheral:(CBPeripheral *)peripheral didUpdateValueForDescriptor:(CBDescriptor *)descriptor error:(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(@"characteristic uuid:%@  value:%@",[NSString stringWithFormat:@"%@",descriptor.UUID],descriptor.value);
    }


5、把数据写到Characteristic中

//写数据 
-(void)writeCharacteristic:(CBPeripheral *)peripheral characteristic:(CBCharacteristic *)characteristic value:(NSData *)value{ 
//打印出 characteristic 的权限,可以看到有很多种,这是一个NS_OPTIONS,就是可以同时用于好几个值,常见的有read,write,notify,indicate,知知道这几个基本就够用了,前连个是读写权限,后两个都是通知,两种不同的通知方式。
 /* 
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 }; 
*/
 NSLog(@"%lu", (unsigned long)characteristic.properties);
 //只有 characteristic.properties 有write的权限才可以写 if(characteristic.properties & CBCharacteristicPropertyWrite){ 
/*
 最好一个type参数可以为CBCharacteristicWriteWithResponse或type:CBCharacteristicWriteWithResponse,区别是是否会有反馈
 */
 [peripheral writeValue:value forCharacteristic:characteristic type:CBCharacteristicWriteWithResponse]; 
}else{
 NSLog(@"该字段不可写!");
 }
 }

6 订阅Characteristic的通知

 //设置通知
 -(void)notifyCharacteristic:(CBPeripheral *)peripheral characteristic:(CBCharacteristic *)characteristic{ 
//设置通知,数据通知会进入:didUpdateValueForCharacteristic方法 [peripheral setNotifyValue:YES forCharacteristic:characteristic];
 }
 //取消通知
 -(void)cancelNotifyCharacteristic:(CBPeripheral *)peripheral characteristic:(CBCharacteristic *)characteristic{ [peripheral setNotifyValue:NO forCharacteristic:characteristic];
 }

7 断开连接(disconnect)

 //停止扫描并断开连接
 -(void)disconnectPeripheral:(CBCentralManager *)centralManager peripheral:(CBPeripheral *)peripheral{ 
//停止扫描
 [centralManager stopScan];
 //断开连接
 [centralManager cancelPeripheralConnection:peripheral]; }

8 模拟器蓝牙调试,慎用,最好还是用真机去调试。

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