iOS从BLE设备读取数据

Question

我正在尝试从BLE设备读取数据，但始终出现权限错误。演示项目可以在这里找到：https : //github.com/sergiomtzlosa/CoreBluetooth-Demo（请记住-我的代码与此代码有些不同）。

一般而言，连接和读取值没有问题，但是有一些特征（必不可少）会导致权限错误。

控制台日志：更新错误！！！特征：“未知（<fff4>）”，错误：“不允许读取”。

因此，当我从该特性订阅或读取数据时，它每次都会向我发送NULL（可能的原因：没有读取权限）。

控制台日志：特征：“未知（<fff4>）”->值：（null）

这是一个代码段：

//Action on discovering services
- (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(@"Discovereddddddddddd service %@", service.UUID);
    [testPeripheral discoverCharacteristics:nil  forService:service];
}
 NSLog(@"didDiscoverServicesEnd");
}

//Action on discovered characteristics
- (void)peripheral:(CBPeripheral *)peripheral
didDiscoverCharacteristicsForService:(CBService *)service error:(NSError *)error {
NSLog(@"didDiscoverCharacteristicsForService!");
for (CBCharacteristic *characteristic in service.characteristics) {
    NSLog(@"Discovered characteristic %@", characteristic.UUID);
    NSLog(@"---------------------------------------------------");
    NSLog(@"Reading value for characteristic %@", characteristic.UUID);
    [peripheral readValueForCharacteristic:characteristic];
    NSLog(@"+++++++++++++++++++++++++++++++++++++++++++++++++++");
    [peripheral setNotifyValue:YES forCharacteristic:characteristic];
    }
}

//Action on reading value
- (void)peripheral:(CBPeripheral *)peripheral 
didUpdateValueForCharacteristic:(CBCharacteristic *)characteristic error:(NSError *)error{
if (error){
    NSLog(@"Update error!!! Characteristic: %@ with error: %@", characteristic.UUID, [error localizedDescription]);
    return;
}else{
    NSData *data = characteristic.value;
    NSString *str = [NSString stringWithUTF8String:[data bytes]];
    NSLog(@"Characteristic: %@ -> with value: %@", characteristic.UUID, str);
}
}

怎么了？无论如何，有没有克服这个问题？

Answer 1

外围设备是嵌入式设备还是其他 iOS 设备。我已经看到外围设备的特性必须显式配置为具有读取权限。仅仅因为你发现了一个特征并不意味着你可以阅读它。