IOS 蓝牙相关-连接外设的代码实现(2)
我们具体说明一下中心模式的应用场景。主设备(手机去扫描连接外设,发现外设服务和属性,操作服务和属性的应用。一般来说,外设(蓝牙设备,比如智能手环之类的东西), 会由硬件工程师开发好,并定义好设备提供的服务,每个服务对于的特征,每个特征的属性(只读,只写,通知等等),本文例子的业务场景,就是用一手机app去读写蓝牙设备。
ios连接外设的代码实现流程
1. 建立中心角色
2. 扫描外设(discover)
3. 连接外设(connect)
4. 扫描外设中的服务和特征(discover)
- 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. 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 xcode
2 开发证书和手机(蓝牙程序需要使用使用真机调试,使用模拟器也可以调试,但是方法很蛋疼,我会放在最后说)
3 蓝牙外设
实现步骤
1 导入CoreBluetooth头文件,建立主设备管理类,设置主设备委托
#import <CoreBluetooth/CoreBluetooth.h>
@interface ViewController : UIViewController<CBCentralManagerDelegate>
@interface ViewController (){
//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
CBCentralManager *manager;
}
- (void)viewDidLoad {
[super viewDidLoad];
/*
设置主设备的委托,CBCentralManagerDelegate
必须实现的:
- (void)centralManagerDidUpdateState:(CBCentralManager *)central;//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)centralManager:(CBCentralManager *)central didDiscoverPeripheral:(CBPeripheral *)peripheral advertisementData:(NSDictionary *)advertisementData RSSI:(NSNumber *)RSSI; //找到外设的委托
- (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
*/
//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
- (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
*/
//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。
4.1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<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];
}
//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];
}
}
4.2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);