Swift 3: unable to connect to peripherals via BLE

Question

I am new to BLE, currently trying to create a simple program that will connect to my BLE user device. I can detect a BLE device, but for some reason I cannot connect to it. I tried to test it using Blue, it shows my device as plug-in and seems to work fine. But in my application, after I discovered the device, does the CB manager try to connect to it and it seems to “freeze”? The didConnect peripheral function never fires, and the peripheral state is forever connected.

How can I identify the problem? Are there any options that I can include in the connection method or somehow track the connection process?

I would appreciate any advice on where to look for problems.

Work in Xcode 8.2.1 using Swift 3. iOS 10.2.1 installed on the test phone

Here is my code:

import UIKit import CoreBluetooth class InfoPageViewController: UIViewController, CBCentralManagerDelegate, CBPeripheralDelegate { var manager:CBCentralManager! var peripheral:CBPeripheral! let BEAN_NAME = "MyDevice" override func viewDidLoad() { super.viewDidLoad() manager = CBCentralManager(delegate: self, queue: nil) } func centralManager(_ central: CBCentralManager, didDiscover peripheral: CBPeripheral, advertisementData: [String : Any], rssi RSSI: NSNumber) { let device = (advertisementData as NSDictionary) .object(forKey: CBAdvertisementDataLocalNameKey) as? NSString if device?.contains(BEAN_NAME) == true { self.manager.stopScan() self.peripheral = peripheral self.peripheral.delegate = self manager.connect(peripheral, options: nil) print("discovered \(BEAN_NAME)") } } func centralManager( central: CBCentralManager, didConnect peripheral: CBPeripheral) { print("connected to \(BEAN_NAME)") peripheral.discoverServices(nil) } 

Answer 1

 func centralManager(central: CBCentralManager, didConnect peripheral: CBPeripheral) {} --------------------^ 

Versus:

 func centralManager(_ central: CBCentralManager, didConnect peripheral: CBPeripheral) --------------------^ 

The method signature is incorrect, you are missing _ .

Method signatures are important. We can assume that since delegate delegation methods are optional, internally, Apple code asks itself: Does my delegate have a func centralManager(_ central: CBCentralManager, didConnect peripheral: CBPeripheral) ( respondsToSelector: method? In your case, no, because it is not the same, and then yours is not called.

You copy / paste the document from the document or delete it and allow Xcode to perform its autocompletion function.