Bluetooth module

Using Bluetooth

There are different ways of using Bluetooth devices in Windows. Using a virtual COM port or using a dedicated Driver.

COM Ports work on virtually all versions of the different software parts, but have a lot of disadvantages. The handling is difficult, you have to use a lot of windows dialogs to set up a connection, and manage the state. Using multiple modules or at least one module on different Vbars is not very straightforward.

The better solution is using a dedicated driver, that is able to control the connection very closely. So it is able to handle errors and reconnects much better.

Virtual COM port

The Bluetooth software package, that comes with your Bluetooth stick contains software, that enables your PC using the VBars BT Extender as a virtual serial port. The Software defines which COM Port is assigned to the connection you have to create by hand.

In case you are not requested to install special Software to use BT, Windows has taken over the control to your BT Radio. So you have to use the BT icon in the Windows Control Panel to create a virtual serial connection.

The connection must be set up manually and repaired manually to in case of a connection loss. In our PC software you have to select the serial port just assigned in Windows to the connection to start communication.

Using a non-Mikado BT module it is needed to work with this connection. But it is a risk because we don't have any control about the data and transfers here.

How to set up the PC software - see here: <<click>>

Bluetooth driver

The new Software uses a special Option "-b" to use the built in Bluetooth driver. This driver itself communicates with windows Bluetooth to manage connections and device searching. This gives tight control over the connection states and enables automatic reconnect i.e. in case of leaving the range of the radios.


The built in driver works with the following Bluetooth stacks.

  • WIDCOMM (Broadcom) BTW Stack software ab version SP5
  • Microsoft Bluetooth stack (Windows XP SP2 or newer)
  • PowerPC- oder Intel-baierte Mac OS X 10.4 (ab Bluetooth v1.2)
  • Linux with BlueZ Bluetooth stack

Since the Windows own stack supports most of the current Bluetooth devices, there is no additional software needed, and the software will run out of the box immediately. 


The Software is to be installed in the normal way, only the option on the command line has to be changed from "-u" to "-b", because we want to use Bluetooth driver instead of USB. You can copy the Symbol on the desktop, so you can use both versions in a row, or even in parallel.

If the software is called first, the very first action is checking, if the Bluetooth stack exists and is supported. If there is encountered a problem, the following message box appears:

Search devices

At startup of the software the bluetooth environment is searched automatically. If you want to show the available devices, you can use the device selection dialog. 

Open connection

If an valid VBar device is found, it is presented in the list. You can open a connection by double clicking the entry or use the connect button. If another connection is currently running, the old connection is closed automatically before opening the new one. With this it's very easy to handle multiple devices. The original Windows Bluetooth stack works very well on quick connecting, so its a matter of seconds switching from one device to another.

Unfortunately it is not always possible to use devices with no pass-code. The Windows built in stack always requires a passkey even if the device itself is configured not to use one. So you have to set a passkey first, before using the bluetooth module.

This is done by entering a 4 digit pass-code in the pc software, while the VBar device is connected through the USB cable. This is for security reasons, it's not very useful if you can change passkeys via Bluetooth. The Passkey shall not contain leading zeros. Example for passkeys: "1234" or "1111" Not valid is: "0123". Note that the Passkey is transmitted to the Bluetooth module only at startup. So you need to power cycle the VBar unit before the first connection attempt. On power cycle, wait 20 secs in off state, so the device really gets a coldstart (Coll Glitch).

On the next start-up, try to open the connection to the Bluetooth module, you will be asked by Windows to enter the passkey. If you once have bound the module to windows, you do not need any passkeys anymore on subsequent connection attempts.

Since Windows stores the Address of the Bluetooth module, and not the name, a Module which is bound once can be exchanged between VBar Controllers with no more pass-code issues.

Close Connection

A Connection can be closed manually. This is not needed normally, since the software now tries to reconnect every time it gets disconnected for some reason. Power off of the Device, or leaving the Bluetooth range. If the Heli comes in Range again, the connection is restored automatically.

Since on reconnect the VBar device is queried for the actual parameters, the displayed data is always current after a delay of a few seconds.


If you have once managed the passkey issue, the use of Bluetooth equipped VBars is really simple. Very similar to USB but without wires.