iOS: Writing is not permitted for write descriptor

I am building simple for Central and Peripheral sample,

Central code works fine as I am able to write both characteristics and descriptor when Android acts as Peripheral,

But when iOS acts as Peripheral,I am unable to write descriptor,

I getting as Error Domain=CBATTErrorDomain Code=3 "Writing is not permitted." UserInfo={NSLocalizedDescription=Writing is not permitted.}

I believe,I had missed something,Any idea what am I doing wrong?

//Peripheral Code            transferCharacteristic = CBMutableCharacteristic(                 type: transferCharacteristicUUID,                 properties: [.indicate,.writeWithoutResponse,.read],                 value: nil,                 permissions: [.writeable,.readable]             )              let userDesc = CBMutableDescriptor(type: userCharacteristicUUID, value: "Used to send commands")              transferCharacteristic?.descriptors = [userDesc]              // Then the service             transferService = CBMutableService(                 type: transferServiceUUID,                 primary: true             )              // Add the characteristic to the service             transferService?.characteristics = [transferCharacteristic!]             peripheralManager!.add(transferService!)             peripheralManager!.startAdvertising([CBAdvertisementDataServiceUUIDsKey : [transferServiceUUID],CBAdvertisementDataLocalNameKey : "Broadcaster"])   //Central Code where it throw error  /** This callback lets us know more data has arrived via notification on the characteristic      */     func peripheral(_ peripheral: CBPeripheral, didUpdateValueFor characteristic: CBCharacteristic, error: Error?) {     var clientDes : CBDescriptor?      for desc in characteristic.descriptors!{         if desc.uuid.uuidString  == CBUUIDCharacteristicUserDescriptionString {             clientDes = desc         }     }  let sendValue:[UInt8] = [0x02, 0x00]         let data = NSData(bytes: sentValue, length: 2)         peripheral.writeValue(data as Data, for: clientDes!) }  //Here I am getting the log     func peripheral(_ peripheral: CBPeripheral, didWriteValueFor descriptor: CBDescriptor, error: Error?) {         print("wrote to \(String(describing: error))")     } 

1 Answers

Answers 1

Although CBPeripheral provides the writeValue(data:Data, descriptor: CBDescriptor) method and the documentation only states that you cannot write to descriptors of type CBUUIDClientCharacteristicConfigurationString, the CBPeripheralManagerDelegate does not offer any way of being notified about a write to a descriptor.

As a result you cannot write to any descriptor from a peripheral provided by CBPeripheralManager.

You should simply create another characteristic to write to.

If You Enjoyed This, Take 5 Seconds To Share It

• Facebook
• Twitter
• Google+
• StumbleUpon
• Digg
• Delicious
• LinkedIn
• Reddit
• Technorati