Bluetooth headset connection detection - iOS

1. Bluetooth audio protocols are commonly divided into two types:

1. One-way high-fidelity audio protocol (ie: output), its common type is BluetoothA2DPOutput, mainly for listening to music and watching videos;

2. Bidirectional low-fidelity audio protocol (ie: output, input), the common types are BluetoothHFP (ie: Hands-Free Profile) and BluetoothHSP (HeadSet Profile), both listening and speaking;

2. Get status

1. Bluetooth is turned on and the headset is not connected - Speaker

2. One-way high-definition audio protocol (output) - BluetoothA2DPOutput

3. Bidirectional low-fidelity audio protocol (output, input) - BluetoothHFP, BluetoothHSP

3. Method implementation

1. Get connection status

#pragma mark - ****************************** 蓝牙耳机是否链接 - 状态
+ (BOOL)isBluetoothHeadsetConnectedState {
    AVAudioSession *session = [AVAudioSession sharedInstance];
    AVAudioSessionRouteDescription *routeDescription = [session currentRoute];
    if (routeDescription) {
        NSArray *outputs = [routeDescription outputs];
        if (outputs && 0 < [outputs count]) {
            AVAudioSessionPortDescription *portDescription = [outputs objectAtIndex:0];
            NSString *portType = [portDescription portType];
            if (portType && [portType isEqualToString:@"BluetoothA2DPOutput"] && [portType isEqualToString:@"BluetoothHFP"] && [portType isEqualToString:@"BluetoothHSP"]) {
                return YES;
            }
        }
    }
    return NO;
}

2. Get the connection entity

#pragma mark - ****************************** 蓝牙耳机是否链接 - 实体
+ (AVAudioSessionPortDescription *)isBluetoothHeadsetConnectedEntity {
    /*
     蓝牙开启未链接耳机:
     Speaker
     
     单向保真音频协议(输出):
     BluetoothA2DPOutput
     ...
     
     双向保真音频协议(输入 & 输入):
     BluetoothHFP - HFP(Hands-Free Profile)
     BluetoothHSP - HSP(HeadSet Profile)
     
     其它:
     Receiver
     */
    AVAudioSession *session = [AVAudioSession sharedInstance];
    AVAudioSessionRouteDescription *routeDescription = [session currentRoute];
//    NSLog(@"%@", routeDescription);
    if (routeDescription) {
        NSArray *outputs = [routeDescription outputs]; // 输入源
        if (outputs && 0 < [outputs count]) {
            AVAudioSessionPortDescription *portDescription = [outputs objectAtIndex:0];
            NSString *portType = [portDescription portType];
            NSLog(@"PortType: %@", portType); // 蓝牙开启未链接: Speaker && 链接耳机: BluetoothA2DPOutput BluetoothHFP BluetoothHSP
            if (portType && [portType isEqualToString:@"BluetoothA2DPOutput"]) {
                NSLog(@"[蓝牙检测] - 状态 - 输出 - %@", [portDescription portName]);
                return  portDescription;
            } else if (portType && [portType isEqualToString:@"BluetoothHFP"] && [portType isEqualToString:@"BluetoothHSP"]) {
                NSLog(@"[蓝牙检测] - 状态 - 输出 & 输入 - %@", [portDescription portName]);
                return portDescription;
            }
        }
    }
    return nil;
}

CoreBluetooth Bluetooth switching status real-time detection

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