Swift Implementation of Bluetooth Message Protocols. Encode and Decode BLE Characteristics
This is not a BLE Manager for your phone. There are plenty of those out there. BluetoothMessageProtocol provides functions for encoding and decoding Bluetooth Characteristic data.
BluetoothMessageProtocol is available through CocoaPods. To install it, simply add the following line to your Podfile:
pod 'BluetoothMessageProtocol'
Swift Package Manager:
dependencies: [
.package(url: "https://github.com/FitnessKit/BluetoothMessageProtocol", from: "2.0.1")
]
The Service class helps to describe a BLE Service. There is no assumption to which Characteristics the Service contains.
Example Using CoreBluetooth:
centralManager.scanForPeripherals(withServices: [CBUUID(string: ServiceHeartRate.uuidString),],
options: [CBCentralManagerScanOptionAllowDuplicatesKey : true])
Each Bluetooth Characteristic has an encode and decode method. When you receive the data from a sensor you call the static decode method to turn the data into a Characteristic Object as seen below in the example:
func peripheral(_ peripheral: CBPeripheral, didUpdateValueFor characteristic: CBCharacteristic, error: Error?) {
if let sensorData = characteristic.value {
if characteristic.uuid.uuidString == CharacteristicHeartRateMeasurement.uuidString {
doDecodeHRMess(sensorData: sensorData)
}
if characteristic.uuid.uuidString == CharacteristicBodySensorLocation.uuidString {
doDecodeBody(sensorData: sensorData)
}
}
}
func doDecodeHRMess(sensorData: Data) {
let hrData: Result<CharacteristicHeartRateMeasurement, BluetoothDecodeError> = CharacteristicHeartRateMeasurement.decode(with: sensorData)
switch hrData {
case .success(let char):
print("HR: \(char.heartRate)")
case .failure(let error):
print(error)
}
/// Or you can stil use the doCatch
do {
let hrData = try CharacteristicHeartRateMeasurement.decode(with: sensorData).get()
print("HR: \(hrData.heartRate)")
} catch {
print(error)
}
}
func doDecodeBody(sensorData: Data) {
let sensor: Result<CharacteristicBodySensorLocation, BluetoothDecodeError> = CharacteristicBodySensorLocation.decode(with: sensorData)
switch sensor {
case .success(let char):
print("Location: \(char.sensorLocation.stringValue)")
case .failure(let error):
print(error)
}
/// Or you can stil use the doCatch
do {
let sensor = try CharacteristicBodySensorLocation.decode(with: sensorData).get()
print("Location: \(sensor.sensorLocation.stringValue)")
} catch {
print(error)
}
}
Manufacturer Specific data contains a Company Assigned Number and specific data defined by the Manufacturer.
Example using Apple iBeacon:
func centralManager(_ central: CBCentralManager, didDiscover peripheral: CBPeripheral, advertisementData: [String : Any], rssi RSSI: NSNumber) {
if let advertData = advertisementData[CBAdvertisementDataManufacturerDataKey] as? Data {
switch ManufacturerDataAppleiBeacon.decode(with: advertData) {
case .success(let beacon):
print(beacon.proximityUUID.uuidString)
case .failure(let error):
print(error)
}
/// Or you can stil use the doCatch
if let beacon = try? ManufacturerDataAppleiBeacon.decode(with: advertData).get() {
print(beacon.proximityUUID.uuidString)
}
}
}
This package is developed and maintained by Kevin A. Hoogheem
BluetoothMessageProtocol is available under the MIT license