Great question! Let’s break this down clearly with practical details:

1. Is there a UUID wildcard/placeholder for CLBeaconRegion? #

Short answer: No, CoreLocation’s CLBeaconRegion does not support wildcard or placeholder values for the proximity UUID. You must provide a specific, valid UUID string when initializing a CLBeaconRegion if you want to use CoreLocation’s beacon scanning APIs.

Your current getBeaconRegion() function uses a hardcoded UUID, which will only detect beacons broadcasting that exact UUID. There’s no way to pass a "catch-all" value here to scan for every possible iBeacon.

2. How to detect any iBeacon (all UUIDs) #

If you need to scan for all iBeacons regardless of their UUID, you’ll need to switch to CoreBluetooth instead of CoreLocation. CoreBluetooth lets you scan for all BLE advertisements, and you can filter those that match the iBeacon advertisement format.

Here’s a step-by-step implementation:

Step 1: Set up required permissions #

Add these entries to your Info.plist to request necessary access:

• NSBluetoothWhenInUseUsageDescription (or NSBluetoothAlwaysUsageDescription for background scanning)
• NSLocationWhenInUseUsageDescription (add NSLocationAlwaysAndWhenInUseUsageDescription if background detection is needed)

Step 2: Implement the CoreBluetooth scanner #

import CoreBluetooth

class UniversalBeaconScanner: NSObject, CBCentralManagerDelegate {
    private var centralManager: CBCentralManager!
    
    override init() {
        super.init()
        centralManager = CBCentralManager(delegate: self, queue: DispatchQueue.main)
    }
    
    func centralManagerDidUpdateState(_ central: CBCentralManager) {
        switch central.state {
        case .poweredOn:
            // Start scanning for all BLE devices (allow duplicates to track RSSI changes)
            centralManager.scanForPeripherals(
                withServices: nil,
                options: [CBCentralManagerScanOptionAllowDuplicatesKey: true]
            )
        case .poweredOff:
            print("Bluetooth is turned off")
        default:
            print("Bluetooth unavailable: \(central.state.rawValue)")
        }
    }
    
    func centralManager(_ central: CBCentralManager, didDiscover peripheral: CBPeripheral, advertisementData: [String : Any], rssi RSSI: NSNumber) {
        // Check if the advertisement data is from an iBeacon
        guard let manufacturerData = advertisementData[CBAdvertisementDataManufacturerDataKey] as? Data else {
            return
        }
        
        // iBeacons use Apple's manufacturer ID (0x004C)
        guard manufacturerData.count >= 25, 
              manufacturerData[0] == 0x4C, 
              manufacturerData[1] == 0x00 else {
            return
        }
        
        // Parse iBeacon details
        let uuid = UUID(data: manufacturerData.subdata(in: 4..<20))!
        let major = UInt16(manufacturerData[20]) << 8 | UInt16(manufacturerData[21])
        let minor = UInt16(manufacturerData[22]) << 8 | UInt16(manufacturerData[23])
        let calibratedPower = Int8(bitPattern: manufacturerData[24])
        
        print("Detected iBeacon:")
        print("UUID: \(uuid.uuidString)")
        print("Major: \(major), Minor: \(minor)")
        print("RSSI: \(RSSI), Calibrated Power: \(calibratedPower)")
        print("---")
    }
}

Step 3: Integrate the scanner into your view controller #

Update your viewDidLoad() to use this universal scanner:

override func viewDidLoad() {
    super.viewDidLoad()
    
    // Request location permission (required for some BLE scanning scenarios)
    let locationManager = CLLocationManager()
    locationManager.requestWhenInUseAuthorization()
    
    // Initialize the universal beacon scanner
    let beaconScanner = UniversalBeaconScanner()
}

Key Notes & Limitations #

• Background Scanning: CoreBluetooth background scanning requires specifying explicit service UUIDs, which isn’t feasible for detecting all iBeacons. For background detection, you’ll need to use CoreLocation with predefined UUIDs (if you know the beacons you care about).
• Battery Impact: Scanning for all BLE devices uses more battery than targeted CoreLocation scans, so use this approach only when necessary.
• iOS Compatibility: This method works on iOS 7 and above, matching CoreLocation’s beacon scanning support.

Content of the question originates from Stack Exchange, question author Andres Gomez