How do I search device using core Bluetooth? - ios

Question

In my iOS app, I want to search device using swift 3. How do I implement this functionality in my app using core Bluetooth?

Answer 1

this below code i what i wrote from rearching in internet and help of my friends to list bluetooth devices and connect to heart rate measure service
class HRMViewController: UIViewController {
#IBOutlet weak var tableView: UITableView!
var cbCentralManager: CBCentralManager?
var cbPeripheral: CBPeripheral?
var discoveredPeripherals = [CBPeripheral]()
var connected = ""
var bodyData = ""
var manufacturer = ""
var deviceData = ""
var heartRate: UInt16 = 0
var localNameArray = [String]()
var pulseTimer: Timer?
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
// Do any additional setup after loading the view.
tableView.register(UITableViewCell.self, forCellReuseIdentifier: "cell")
tableView.backgroundColor = UIColor.lightGray
tableView.layer.borderColor = UIColor.lightGray.cgColor
tableView.layer.borderWidth = 1.0
tableView.layer.cornerRadius = 2.0
tableView.layer.masksToBounds = true
let centralManager = CBCentralManager(delegate: self, queue: nil)
self.cbCentralManager = centralManager
}
}
extension HRMViewController : CBCentralManagerDelegate, CBPeripheralDelegate {
func centralManager(_ central: CBCentralManager, didDiscover peripheral: CBPeripheral, advertisementData: [String : Any], rssi RSSI: NSNumber) {
let localName = advertisementData[CBAdvertisementDataLocalNameKey] as? String ?? ""
if localName.count > 0 {
if RSSI.intValue > signalStrengthMax {
if let index = self.discoveredPeripherals.index(of: peripheral) {
self.discoveredPeripherals.remove(at: index)
self.localNameArray.remove(at: index)
self.tableView.reloadData()
}
return
}
if RSSI.intValue < signalStrengthMin {
if let index = self.discoveredPeripherals.index(of: peripheral) {
self.discoveredPeripherals.remove(at: index)
self.localNameArray.remove(at: index)
self.tableView.reloadData()
}
return
}
print("Discovered: \(peripheral.name ?? "a device") with udid: \(peripheral.identifier) at \(RSSI)")
if !(self.discoveredPeripherals.contains(peripheral)) {
self.discoveredPeripherals.append(peripheral)
self.localNameArray.append(localName)
self.tableView.reloadData()
}
}
}
func centralManager(_ central: CBCentralManager, didConnect peripheral: CBPeripheral) {
peripheral.delegate = self
peripheral.discoverServices(nil)
self.connected = "Connected: \((peripheral.state == .connected) ? "Yes" : "No")"
}
func centralManagerDidUpdateState(_ central: CBCentralManager) {
if central.state != .poweredOn {
return
}
if central.state == .poweredOn {
let deviceService = CBUUID(string: HRMConstants.Services.deviceInfoUUID)
let heartRateService = CBUUID(string: HRMConstants.Services.heartRateUUID)
let services = [deviceService,heartRateService]
cbCentralManager?.scanForPeripherals(withServices: services, options: nil)
}
}
func peripheral(_ peripheral: CBPeripheral, didDiscoverServices error: Error?) {
for service in peripheral.services ?? [CBService]() {
peripheral.discoverCharacteristics(nil, for: service)
}
}
func peripheral(_ peripheral: CBPeripheral, didDiscoverCharacteristicsFor service: CBService, error: Error?) {
if service.uuid == CBUUID(string: HRMConstants.Services.heartRateUUID) {
for character in service.characteristics ?? [CBCharacteristic]() {
if character.uuid == CBUUID(string: HRMConstants.Characteristics.measurementUUID) {
self.cbPeripheral?.setNotifyValue(true, for: character)
}
else if character.uuid == CBUUID(string: HRMConstants.Characteristics.bodyLocationUUID) {
self.cbPeripheral?.readValue(for: character)
}
}
}
if service.uuid == CBUUID(string: HRMConstants.Services.deviceInfoUUID) {
for character in service.characteristics ?? [CBCharacteristic]() {
if character.uuid == CBUUID(string: HRMConstants.Characteristics.manufacturerNameUUID) {
self.cbPeripheral?.readValue(for: character)
}
}
}
}
func peripheral(_ peripheral: CBPeripheral, didUpdateValueFor characteristic: CBCharacteristic, error: Error?) {
if characteristic.uuid == CBUUID(string: HRMConstants.Characteristics.measurementUUID) {
self.getHeartRateData(for: characteristic, error: error)
}
if characteristic.uuid == CBUUID(string: HRMConstants.Characteristics.manufacturerNameUUID) {
self.getManufacturerName(for: characteristic)
}
else if characteristic.uuid == CBUUID(string: HRMConstants.Characteristics.bodyLocationUUID) {
self.getBodyLocation(for: characteristic)
}
}
}
extension HRMViewController {
func getHeartRateData(for characteristic: CBCharacteristic, error: Error?) {
if let _ = error {
print("Error: \(error?.localizedDescription ?? "Unknown")")
return
}
guard let value = characteristic.value else { return }
let bpm : UInt16
if (value[0] & 0x01) == 0 {
bpm = UInt16(value[1])
} else {
bpm = UInt16(littleEndian: value.subdata(in: 1..<3).withUnsafeBytes { $0.pointee } )
}
heartRate = bpm
doHeartBeat()
pulseTimer = Timer.scheduledTimer(timeInterval: 60.0 / Double(heartRate), target: self, selector: #selector(self.doHeartBeat), userInfo: nil, repeats: false)
/*
var reportData = [UInt8](value)
var bpm: UInt16 = 0
if (reportData[0] & 0x01) == 0 {
bpm = UInt16(reportData[1])
}
else {
bpm = CFSwapInt16LittleToHost(UInt16(reportData[1]))
}
heartRate = bpm
doHeartBeat()
pulseTimer = Timer.scheduledTimer(timeInterval: 60.0 / Double(heartRate), target: self, selector: #selector(self.doHeartBeat), userInfo: nil, repeats: false)
*/
}
func getManufacturerName(for characteristic: CBCharacteristic) {
guard let value = characteristic.value else { return }
let manufacturerName = String(data: value, encoding: .utf8)
}
func getBodyLocation(for characteristic: CBCharacteristic) {
guard let value = characteristic.value else { return }
var location = ""
// 1
var bodyData = [UInt8](value)
if !bodyData.isEmpty {
let bodyLocation: UInt8 = bodyData[0]
// 2
location = "Body Location: \(bodyLocation == 1 ? "Chest" : "Undefined")"
// 3
}
else {
// 4
location = "Body Location: N/A"
}
print(location)
}
#objc func doHeartBeat() {
}
}
extension HRMViewController : UITableViewDelegate, UITableViewDataSource {
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell")
cell?.textLabel?.text = "\(localNameArray[indexPath.row]) \(discoveredPeripherals[indexPath.row].identifier )"
return cell!
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
let newPeripheral = discoveredPeripherals[indexPath.row]
if let _ = cbPeripheral { // had a device selected already
if newPeripheral != cbPeripheral! { // clean up old peripheral
self.cleanUp()
}
}
cbPeripheral = newPeripheral
self.cbCentralManager?.stopScan()
cbPeripheral?.delegate = self
self.cbCentralManager?.connect(cbPeripheral!, options: nil)
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return discoveredPeripherals.count
}
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return 45.0
}
func cleanUp() {
if !(cbPeripheral!.state == .connected) { // Don't do anything if we're not connected
return
}
if let services = self.cbPeripheral!.services {
for eachService in services {
if let characteristics = eachService.characteristics {
for eachCharacteristic in characteristics {
if eachCharacteristic.uuid.isEqual(CBUUID(string: HRMConstants.Characteristics.bodyLocationUUID)) {
if eachCharacteristic.isNotifying {
self.cbPeripheral?.setNotifyValue(false, for: eachCharacteristic)
}
}
if eachCharacteristic.uuid.isEqual(CBUUID(string: HRMConstants.Characteristics.manufacturerNameUUID)) {
if eachCharacteristic.isNotifying {
self.cbPeripheral?.setNotifyValue(false, for: eachCharacteristic)
}
}
if eachCharacteristic.uuid.isEqual(CBUUID(string: HRMConstants.Characteristics.measurementUUID)) {
if eachCharacteristic.isNotifying {
self.cbPeripheral?.setNotifyValue(false, for: eachCharacteristic)
}
}
}
}
}
}
self.cbCentralManager?.cancelPeripheralConnection(self.cbPeripheral!)
self.cbPeripheral = nil
}
}
and for constants
struct HRMConstants {
struct Services {
static let deviceInfoUUID = "180A"
static let heartRateUUID = "180D"
}
struct Characteristics {
static let measurementUUID = "2A37"
static let bodyLocationUUID = "2A38"
static let manufacturerNameUUID = "2A29"
}
}
with this you will get the basic idea and then you can try it for yourself
see for ble doc for different bluetooth services