sending data to bluetooth module to be read by arduino rom iOS swift 3

If i want to send data to a bluetooth module, which is connected to the Arduino, what code lines are specifically the ones I need to take notice of.

I want to send something like, the number '75' to the bluetooth module and the Arduino will read it

thanks

Bluetooth LE is very long and cumbersome with many delegates in between. The minimum path to write your data is:

1. Make sure you have bluetooth permission: CBCentralManagerDelegate.centralManagerDidUpdateStateand if so start scanning with scanForPeripherals
2. CBCentralManagerDelegate.didDiscover If this is the peripheral you want then set yourself as its delegate
3. CBPeripheralDelegate.peripheral:didDiscoverServices: If this is the service you want then stop scanning and discoverCharacteristics:for: service

4. CBPeripheralDelegate.peripheral:didDiscoverCharacteristicsFor: service If a characteristic in the array of characteristics is the one you want then:

   func peripheral(_ peripheral: CBPeripheral, didDiscoverCharacteristicsFor service: CBService, error: Error?) {
       guard let characteristics = service.characteristics else {
           return
       }
       for characteristic in characteristics {
           if characteristic.uuid == CBUUID(string: characteristicIdentifier) {
               let value: UInt8 = 75
               let data = Data(bytes: [value])
               peripheral.writeValue(data, for: characteristic, type: .withResponse)
           }
       }
   }