How to retrieve data from BLE device in iOS? - swift

Question

I would like to get data from BLE device which is offering two services and among them, one is offering 3 characteristics and another one is offering 2 characteristics.
Could you please explain how to retrieve data from device in Swift.
Please have a look give proper code
extension PeripheralConnectedViewController: CBPeripheralDelegate {
func centralManager(_ central: CBCentralManager, didFailToConnectPeripheral peripheral: CBPeripheral, error: NSError?) {
if let error = error {
print("Error connecting peripheral: \(error.localizedDescription)")
}
}func peripheral(_ peripheral: CBPeripheral, didDiscoverServices error: Error?) {
if let error = error {
print("Error discovering services: \(error.localizedDescription)")
}
peripheral.services?.forEach({ (service) in
services.append(service)
tableView.reloadData()
peripheral.discoverCharacteristics(nil, for: service)
})
}func peripheral(_ peripheral: CBPeripheral, didDiscoverCharacteristicsFor service: CBService, error: Error?) {
if let error = error {
print("Error discovering service characteristics: \(error.localizedDescription)")
}
service.characteristics?.forEach({ characteristic in
if let descriptors = characteristic.descriptors {
print(descriptors)
}
print(characteristic.properties)
})
for newChar: CBCharacteristic in service.characteristics!{
peripheral.readValue(for: newChar)
peripheral.setNotifyValue(true, for: newChar)
}
}
func peripheral(_ peripheral: CBPeripheral, didReadRSSI RSSI: NSNumber, error: Error?) {
switch RSSI.intValue {
case -90 ... -60:
rssiLabel.textColor = .btOrange
break
case -200 ... -90:
rssiLabel.textColor = .btRed
break
default:
rssiLabel.textColor = .btGreen
}
rssiLabel.text = "\(RSSI)dB"
}func peripheral(_ peripheral: CBPeripheral, didUpdateValueFor characteristic: CBCharacteristic, error: Error?) {
if var enableValue = Character("?").asciiValue{
let enablyBytes = NSData(bytes: &enableValue, length: MemoryLayout<UInt8>.size)
self.peripheral.writeValue(enablyBytes as Data, for: characteristic, type: CBCharacteristicWriteType.withResponse)
}
print(characteristic)
}
func peripheral(_ peripheral: CBPeripheral, didUpdateNotificationStateFor characteristic: CBCharacteristic, error: Error?) {
}