This article illustrates how to install a Bluetooth USB adapter on the CORE9G25 boards and how to use it to comunicate with other Bluetooth devices using the Linux standard utilities

The default Linux Debian distribution has the Bluetooth driver already installed so plugging a Bluetooth USB adapter and typing dmesg you will obtain the following messages:

debarm:~# dmesg
...
usb 1-1: new full speed USB device using at91_ohci and address 2                
Bluetooth: Core ver 2.15                                                        
NET: Registered protocol family 31                                              
Bluetooth: HCI device and connection manager initialized                        
Bluetooth: HCI socket layer initialized                                         
Bluetooth: Generic Bluetooth USB driver ver 0.6                                 
usbcore: registered new interface driver btusb
 
debarm:~# lsusb
Bus 002 Device 002: ID 1131:1004 Integrated System Solution Corp. Bluetooth Device
Bus 001 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
debarm:~#

Install Bluez

Bluez is the Official Linux Bluetooth protocol stack (http://www.bluez.org/) and you need to install it to do any further action with Bluetooth. This stack is available as standard Debian package with the name bluez-utils so to install it simply type:

debarm:~# apt-get update
...
debarm:~# apt-get install bluez
...

then type again:

debarm:~# dmesg
...
Bluetooth: L2CAP ver 2.15
Bluetooth: L2CAP socket layer initialized
Bluetooth: RFCOMM TTY layer initialized
Bluetooth: RFCOMM socket layer initialized
Bluetooth: RFCOMM ver 1.11
Bluetooth: BNEP (Ethernet Emulation) ver 1.3
Bridge firewalling registered
Bluetooth: SCO (Voice Link) ver 0.6
Bluetooth: SCO socket layer initialized

Discover the Bluetooth devices in range

Turn on you mobile phone and enable on it the Bluetooth features.

On the FOX command line type hcitool scan to discover the Bluetooth devices visible from your board:

debarm:~# hcitool scan
Scanning ...
        00:25:48:FC:98:6D       Sergio

On this list Sergio is my own mobile phone name and 00:25:48:FC:98:6D is its Bluetooth unique address (learn more about hcitool...).

Let's try to check which services are available on my mobile phone typing:

debarm:~# sdptool search OPUSH 00:25:48:FC:98:6D                                
Inquiring ...                                                                   
Searching for OPUSH on 00:25:48:FC:98:6D ...                                    
Service Name: OBEX Object Push                                                  
Service RecHandle: 0x1000a                                                      
Service Class ID List:                                                          
  "OBEX Object Push" (0x1105)                                                   
Protocol Descriptor List:                                                       
  "L2CAP" (0x0100)                                                              
  "RFCOMM" (0x0003)                                                             
    Channel: 6                                                                  
  "OBEX" (0x0008)                                                               
Language Base Attr List:                                                        
  code_ISO639: 0x454e                                                           
  encoding:    0x6a                                                             
  base_offset: 0x100                                                            
Profile Descriptor List:                                                        
  "OBEX Object Push" (0x1105)                                                   
    Version: 0x0100

OBEX is the first service we'll use to do the first experiment and it is on the Channel 6.

OBEX (abbreviation of OBject EXchange) is a communications protocol that facilitates the exchange of binary objects between devices. OpenOBEX, an open source implementation of the OBEX protocol, is used on the Debian Linux distribution.

Send an image to your mobile phone

Let's try to use OBEX to send an image to our Bluetooth mobile phone.

Download on your FOX this image:

typing:

wget http://www.CORE9G25systems.it/download/examples/tuxcase.jpg          
--2010-08-20 13:55:19--  http://www.CORE9G25systems.it/download/examples/tuxcase.jpg
Resolving www.CORE9G25systems.it... 78.47.10.198                                    
Connecting to www.CORE9G25systems.it|78.47.10.198|:80... connected.                 
HTTP request sent, awaiting response... 200 OK                                  
Length: 4710 (4.6K) [image/jpeg]                                                
Saving to: `tuxcase.jpg'                                                        
                                                                                
100%[======================================>] 4,710       --.-K/s   in 0.07s    
                                                                                
2010-08-20 13:55:20 (69.0 KB/s) - `tuxcase.jpg' saved [4710/4710]               
                                                                                
debarm:~# 

Now install ObexFtp an utility to transfer files using the OBEX protocol (learn mode about ObexFtp...).

debarm:~# apt-get install obexftp
...

then send the Tux to your mobile phone typing:

debarm:~# obexftp --nopath --noconn --uuid none --bluetooth 00:25:48:FC:98:6D --channel 6 -p tuxcase.jpg 
Suppressing FBS.
Connecting..\done
Tried to connect for 628ms
Sending "tuxcase.jpg"...|done
Disconnecting../done

Enable the Linux Kernel Bluetooth support on CORE9G25

$ make ARCH=arm menuconfig
[*] Networking support  --->
  <*>   Bluetooth subsystem support  ---> 
     --- Bluetooth subsystem support
       [*]   L2CAP protocol support
       [ ]   SCO links support (NEW)
       <*>   RFCOMM protocol support
       [ ]     RFCOMM TTY support (NEW)
       < >   BNEP protocol support (NEW)
       < >   HIDP protocol support (NEW)
       Bluetooth device drivers  --->
            <*> HCI USB driver
            < > HCI SDIO driver
            <*> HCI UART driver
            [ ]   UART (H4) protocol support (NEW)
            [ ]   BCSP protocol support (NEW)
            [ ]   Atheros AR300x serial support (NEW)
            [ ]   HCILL protocol support (NEW)
            < > HCI BCM203x USB driver (NEW)
            < > HCI BPA10x USB driver (NEW)
            < > HCI BlueFRITZ! USB driver (NEW)
            < > HCI VHCI (Virtual HCI device) driver (NEW)
            < > Marvell Bluetooth driver support (NEW)
            < > Atheros firmware download driver (NEW)