var manager: CBCentralManager!
var device: CBPeripheral?
var characteristics: [CBCharacteristic]?
var serviceUUID = "1234"
var char1 = "FFE1"
let deviceName = "HMSoft"

func peripheral(_ peripheral: CBPeripheral, didDiscoverCharacteristicsFor service: CBService, error: Error?) {
    DidDiscoverChar.text = "Characteristic found!"

    device = peripheral
    characteristics = service.characteristics

    var value: UInt8 = 1

    let data = NSData(bytes: &value, length: MemoryLayout<UInt8>.size)

    for characteristic in service.characteristics as [CBCharacteristic]!
    {
        if(characteristic.uuid.uuidString == "FFE1")
        {
            device?.writeValue(data as Data, for: characteristic,type: CBCharacteristicWriteType.withoutResponse)

        }
    }
}

@IBAction func ledOn(_ sender: AnyObject) {
    var value: UInt8 = 1
    let data = NSData(bytes: &value, length: MemoryLayout<UInt8>.size)

    device?.writeValue(data as Data, for: characteristics,type: CBCharacteristicWriteType.withoutResponse)
}

device?.writeValue(data as Data, for: characteristics,type: CBCharacteristicWriteType.withoutResponse)