Manually using Bluetooth

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Bluetooth is one of the core functions of the Neo1973, however it is basically unimplemented on the software side at the moment. Hardware problems in the P1 phone mean that the CPU has to be active in order to wake on external bluetooth events, which will reduce the battery life to some 2 days at best in standby.

This page details how to use bluetooth from the command line. We have quite a lot of plans about what exactly Bluetooth should be used for.

Power it up

Bluetooth may not be powered up.

Power up the adapter:

root@fic-gta01:~$ echo "1" > /sys/bus/platform/devices/gta01-pm-bt.0/power_on

If that doesn't do it, power up and reset the adapter one after the other:

root@fic-gta01:~$ echo "1" > /sys/bus/platform/devices/gta01-pm-bt.0/power_on ; 
echo "1" > /sys/bus/platform/devices/gta01-pm-bt.0/reset ;
echo "0" > /sys/bus/platform/devices/gta01-pm-bt.0/reset

hciconfig should print information about the adapter if it powered up properly:

hciconfig

(If you have an older rootfs, you may need to modprobe gta01-pm-bt or even hci_usb but these are built in/loaded automatically currently.) The devices should show as UP. If not you can use

hciconfig <device> up

Bluetooth Functions

Scanning for bluetooth devices

hcitool scan

This will list the addresses of any discoverable bluetooth devices in the vicinity

passkey agent example

There should be a passkey agent built into openmoko, but for now you can start up the example passkey agent and set the pin code there. This will allow for new pairings to be made when you attempt a connection.

passkey-agent --default 0000 &

HID (Human Input Device)

Being able to use HID devices

We want to be able to use a bluetooth keyboard to type into the various applications of our Neo1973. To use a Bluetooth Keyboard type: (11:22:33:44:55:66 is the Address of your BT-Keyboard)

hidd --connect 11:22:33:44:55:66

and press "Connect" on your BT-KB

Tested on:

• Logitech Dinovo Edge
• Nokia SU-8W. Switched on the BT keyboard, scanned for BT address and ran the connect statement above. Works fine.

Acting as HID device

We want to be able to use the Neo1973 as a HID device, being able to use it as controller for presentations.

RFCOMM

Here's how to connect to an external Bluetooth GPS and read NMEA data (Tested with a Holux GPSSlim236).

First, switch on the GPS and identify the BT address:

 hcitool scan

Then, edit /etc/bluetooth/rfcomm, which by default has all settings commented out, to something like this:

 rfcomm0 {
       # Automatically bind the device at startup
       bind no;
       # Bluetooth address of the device
       device 00:11:22:33:44:55;
       # RFCOMM channel for the connection (check your GPS docs for details)
       channel 1;
       # Description of the connection
       comment "Bluetooth GPS";
 }

Restart the BT services:

 root@neo:~$ /etc/init.d/bluetooth stop
 root@neo:~$ /etc/init.d/bluetooth start

You should now be able to bind the GPS to /dev/rfcomm0, like this:

 root@neo:~$ rfcomm bind 0

Confirm the connect:

 root@neo:~$ rfcomm
 rfcomm0: 00:11:22:33:44:55 channel 1 clean 

... and watch the NMEA strings coming from your GPS:

 root@neo:~$ cat /dev/rfcomm0 
 $GPGGA,111748.000,5907.6964,N,01121.1787,E,1,06,1.2,57.7,M,40.1,M,,0000*6F
 $GPRMC,111748.000,A,5907.6964,N,01121.1787,E,0.00,94.94,160807,,,A*50
 $GPVTG,94.94,T,,M,0.00,N,0.0,K,A*3D

If you have nothing better to do, you can now pinpoint my office :-).

OBEX

Networking

Bluetooth should behave just like our usbnet and provide full TCP/IP access to the phone. BNEP has to be used.

On the laptop:

• Start bluetooth

elara /home/alphaone # /etc/init.d/bluetooth start

• Start pand as server

elara /home/alphaone # pand -s

• As soon as pand is started on the phone configure your IP address

elara /home/alphaone # ip a add 10.0.0.1/24 dev bnep0
elara /home/alphaone # ip l set bnep0 up

• Configure IP forwarding and masquerading to your liking

On the phone:

• Power on bluetooth (see above)

• Scan for the laptop

root@fic-gta01:~$ hcitool scan
Scanning ...
        00:0E:6D:C0:0l:6A       Sho
        00:20:E0:5A:FE:C8       BlueZ (0)

• Connect to the laptop pand

root@fic-gta01:~$ pand -c 00:20:E0:5A:FE:C8

• Configure your IP address

ip a add 10.0.0.2/24 dev bnep0
ip r add default via 10.0.0.1

• Enjoy

root@fic-gta01:~$ wget http://www-public.tu-bs.de:8080/~y0019680/tmp/thereisnophone.mp3 
Connecting to www-public.tu-bs.de[134.169.9.108]:8080
thereisnophone.mp3   100****************************************************|   266 KB 00:00:00 ETA
root@fic-gta01:~$ madplay thereisnophone.mp3 
MPEG Audio Decoder 0.15.2 (beta) - Copyright (C) 2000-2004 Robert Leslie et al.
630 frames decoded (0:00:22.6), -0.9 dB peak amplitude, 0 clipped samples

PPP Networking

If you are unable to use the 'BNEP' method described above, you may be able to use a dialup-networking emulation mode. On the Neo:

• Edit the /etc/default/bluetooth file and set the following options:

RFCOMM_ENABLE=true
DUND_ENABLE=true
DUND_OPTIONS="--listen --persist call dun"

• Create an /etc/ppp/peers/dun file with options like the following:

115200
192.168.2.202:192.168.2.200
passive
local
noipdefault
noauth
nodefaultroute

• Restart bluetooth (/etc/init.d/bluetooth stop ; /etc/init.d/bluetooth start)

To connect from a MacOS 10.3 client:

• Open "Applications/Utilities/Bluetooth Serial Utility"

• Click on "New"

• Choose a name, then click "Choose Device"

• Locate your Neo, then select the "LAN Access Point" service. If your device is not found, or if this service does not show up, then you will need to troubleshoot and fix that before continuing. Bluetooth is designed for short-range communication, so make sure that the devices are physically close to each other.

• Select "Port type: RS-232" and "Show in Network Preferences". Click OK.

• Open the Network Preferences page then "Show: Network Port Configurations". Enable the new device that you defined in the previous step and drag it to the bottom of the device list (so that it will not interfere with your other network connections)

• Choose "Show: <your-device-name>", then click "Modem"

• Select "Null Modem 115200" from the list of available devices. Uncheck "Wait for dial tone" and "Enable error correction and compression in modem". Optionally check "Show modem status in menu bar".

• Click "Connect". If everything worked, you will end up with a 'ppp0' device on your Mac with a local address of 192.168.2.200 and you will be able to access your Neo at 192.168.2.202.

A2DP

The A2DP codec, SBC, runs pretty well now in 32-bit fixed-point math. It's been successfully tested on a faster ARM but not yet on neo. There is test code in the bluetooth-alsa.sf.net plugz module for using alsa plugins to send A2DP audio out and it's starting to be reimplemented "properly" in the bluez core.

Headset Audio

Bluez has an audio daemon for headset audio that should work to set up the control connection to the headset. It will need hooks in the openmoko gui.

Neo1973_Audio_Subsystem has more detail about what magic needs to happen with the Wolfson codec so system audio can be switched to use the bluetooth audio channel and later back to the speaker/earpiece/wired headset. There seems to be a proposal for audio scenario management there but no detail about whether that is how things are done currently. How should audio management work when eg plugging in/unplugging the wired headset?

If the codec audio management is worked out, then all we need are hooks to make the kind of dbus api calls that are in the python examples at http://wiki.bluez.org/wiki/HOWTO/AudioDevices (unfortunately python-dbus is not available yet on neo to try these directly). The connect method *does* need to be called; it's automatic only when using an alsa plugin which is not how it works on neo.

Further reading

http://www.holtmann.org/papers/bluetooth/ols2006_slides.pdf http://wiki.bluez.org/wiki/Audio#org.bluez.AudioBluetooth

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