基础知识了解
- peripheral 外设,被连接的设备为perilheral
- central 发起连接的时central
- service and characteristic 服务和特征 每个设备都会提供服务和特征，类似于服务端的api，但是由于结构不同,每个外设会有很多的服务，每个服务中又包含很多字段，这些字段的权限一般分为 读read，写write，通知notiy几种，就是我们连接设备后具体需要操作的内容。
- Description 每个characteristic可以对应一个或多个Description用户描述characteristic的信息或属性
- Characteristic 一个characteristic包括一个单一变量和0-n个用来描述characteristic变量的descriptor，characteristic可以被认为是一个类型，类 似于类。
- Descriptor Descriptor用来描述characteristic变量的属性。例如，一个descriptor可以规定一个可读的描述，或者一个characteristic变量可接受的 范围，或者一个characteristic变量特定的测量单位。
- Service service是characteristic的集合
BLE中的开发要使用CoreBluetooth框架 CoreBluetooth框架的核心其实是两个东西，peripheral和central, 可以理解成外设和中心。对应他们分别有一组相关的API和类蓝牙设备的几种状态:
- 准备（standby）
- 广播（advertising）
- 监听扫描（Scanning
- 发起连接（Initiating）
- 已连接（Connected）
作为中心模式流程:
-
建立中心角色
-
扫描外设（discover）
-
连接外设(connect)
-
扫描外设中的服务和特征(discover)
- 获取外设的services
- 获取外设的Characteristics,获取Characteristics的值，获取Characteristics的Descriptor和Descriptor的值
-
与外设做数据交互(explore and interact)
-
订阅Characteristic的通知
-
断开连接(disconnect)
作为外设模式流程:
- 启动一个Peripheral管理对象
- 本地Peripheral设置服务,特性,描述，权限等等
- Peripheral发送广告
- 设置处理订阅、取消订阅、读characteristic、写characteristic的委托方法
具体实施如下
- 首先导入工具类, 设置代理
[BLEManager.shareInstance setDelegate:self];
- 搜索设备
#pragma mark- 开始搜索
- (void)beginScan{
[self.cbCM scanForPeripheralsWithServices:nil options:nil];
}
- 连接设备
#pragma mark- 连接设备
- (void)connect:(CBPeripheral *)peripheral{
[self.cbCM stopScan];
[self.cbCM connectPeripheral:peripheral options:nil];
}
- 判断是否连接成功
#pragma mark- 连接成功
- (void)centralManager:(CBCentralManager *)central didConnectPeripheral:(CBPeripheral *)peripheral{
connectPeripheral = peripheral;
peripheral.delegate = self;
[peripheral discoverServices:nil];
if ([self.delegate respondsToSelector:@selector(didConnectPeripheral:)]) {
[self.delegate didConnectPeripheral:peripheral];
}
}
#pragma mark- 连接失败
- (void)centralManager:(CBCentralManager *)central didFailToConnectPeripheral:(CBPeripheral *)peripheral error:(NSError *)error{
if ([self.delegate respondsToSelector:@selector(didFailToConnectPeripheral:error:)]) {
[self.delegate didFailToConnectPeripheral:peripheral error:error];
}
}
- 设置服务和特征
//发现服务
- (void)peripheral:(CBPeripheral *)peripheral didDiscoverServices:(NSError *)error{
for (CBService *s in peripheral.services) {
if ([s.UUID.UUIDString isEqualToString:self->serviceUUIDString]) {
//这里可以通过service的UUID属性来辨识你要的服务
[peripheral discoverCharacteristics:nil forService:s];
}
}
}
//设置特征属性值
- (void)peripheral:(CBPeripheral *)peripheral didDiscoverCharacteristicsForService:(CBService *)service error:(NSError *)error{
for (CBCharacteristic *characteristic in service.characteristics) {
if ([characteristic.UUID isEqual:[CBUUID UUIDWithString:self->notify]]){
// 订阅, 实时接收
[peripheral setNotifyValue:YES forCharacteristic:characteristic];
}
}
for (CBCharacteristic *characteristic in service.characteristics) {
if ([characteristic.UUID isEqual:[CBUUID UUIDWithString:self->write]]){
self.writeCharacteristic = characteristic;
}
}
}
- 发送数据
#pragma mark- 发送数据
- (void)write:(NSData *)data withResponse:(BOOL)withResponse{
if(!_writeCharacteristic){
NSLog(@"writeCharacteristic is nil!");
return;
}
[connectPeripheral writeValue:data forCharacteristic:self.writeCharacteristic type:withResponse ? CBCharacteristicWriteWithResponse : CBCharacteristicWriteWithoutResponse];
}
- 接收回调数据
#pragma mark- 蓝牙数据接收
- (void)peripheral:(CBPeripheral *)peripheral didUpdateValueForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error{
if ([characteristic.UUID isEqual:[CBUUID UUIDWithString:self->serviceUUIDString]]) {
NSData *data = characteristic.value;
if (data) {
if ([self.delegate respondsToSelector:@selector(bleGattServiceDataReceived:)]) {
[self.delegate bleGattServiceDataReceived:data];
}
}
}
}
- 实时监测蓝牙状态
#pragma mark- 蓝牙状态的改变
- (void)centralManagerDidUpdateState:(nonnull CBCentralManager *)central {
switch (central.state) {
case CBManagerStateUnknown:
//未知状态
break;
case CBManagerStateResetting:
//蓝牙重置中
break;
case CBManagerStateUnsupported:
//蓝牙不支持
break;
case CBManagerStateUnauthorized:
//没有权限
break;
case CBManagerStatePoweredOff:
//蓝牙为开启
break;
case CBManagerStatePoweredOn:
//蓝牙已开启
break;
default:
break;
}
}
