PiBox

I tested Buildroot 2015.02. It builds fine with the attached minor patch (to PiBox configs, not to Buildroot). I then created a bluez-tools metabuild. I'm not sure if that works yet, however. I got distracted by having to migrate from Gitorious to GitLab. Now that the migration is complete I can get back to continue testing the bluez-tools build.

Cross compile seems to be failing. I'm getting errors that the compiler won't build an executable.

Here is some info on cross compiling bluez: http://wiki.beyondlogic.org/index.php?title=Cross_Compiling_BlueZ_Bluetooth_tools_for_ARM

Created upstream repo @ GitLab.com and pushed.

Package now just needs to be tested to see if it works.

hciconfig shows the device if I inserted it after starting bluetoothd:

hci0:   Type: BR/EDR  Bus: USB
        BD Address: 00:1A:7D:DA:71:13  ACL MTU: 310:10  SCO MTU: 64:8
        UP RUNNING PSCAN 
        RX bytes:606 acl:0 sco:0 events:36 errors:0
        TX bytes:939 acl:0 sco:0 commands:36 errors:0

I haven't had time to try anything else yet. I need to review some of the links in this issue first.

General probing¶

• load the bt modules: modprobe btusb
• Run hciconfig to see if the device is working:
• Verify local bt is working: hciconfig
  

  hci0:   Type: BR/EDR  Bus: USB
          BD Address: 00:1A:7D:DA:71:13  ACL MTU: 310:10  SCO MTU: 64:8
          UP RUNNING PSCAN 
          RX bytes:1158 acl:0 sco:0 events:63 errors:0
          TX bytes:1050 acl:0 sco:0 commands:63 errors:0
  

• Look for other devices: hcitool scan
  • Make bluetooth device visible to world (on phone, see bluetooth settings)
  • Run this command, get back something like this:
    

    # hcitool scan
    Scanning ...
            64:89:9A:F2:4B:58       LG Volt
    

• Ping the device: l2ping 64:89:9A:F2:4B:58
  

  # l2ping 64:89:9A:F2:4B:58
  Ping: 64:89:9A:F2:4B:58 from 00:1A:7D:DA:71:13 (data size 44) ...
  0 bytes from 64:89:9A:F2:4B:58 id 0 time 12.57ms
  ...
  

• Browse services: sdptool browse 64:89:9A:F2:4B:58
  • Returns lots of info

This can be used with bt-obex for file transfer. Now I need to find out how to setup audio.

Pairing for Audio¶

• bt-audio -c 64:89:9A:F2:4B:58
  I haven't tried this yet, however. Bluetooth on Raspberry has some additional info though it appears to use older versions of the bluez tools (bluetoot-agent instead of bt-agent).

Links¶

1. How to run BlueZ
2. Archlinux Bluetooth
3. BluetoothUser/a2dp
4. Bluetooth on Raspberry - Audio Streaming
5. How to connect to Bluetooth headset/soundbar/speaker
   1. Looks like a definitive example using bluez-tools
6. bt-audio man page
7. Bluetooth for Programmers
   1. This discusses programming using libbluetooth, which is installed in PiBox.
8. Bluetooth Headset
   1. This says that BlueZ5 is not supported by Alsa, only PulseAudio. So I'll have to work with BlueZ 4.x to skip PulseAudio. # PiBox does not currently have an /etc/bluetooth/audio.conf file. There is an example of one on kepler. Question: why isn't there a default audio.conf? It came from bluez-utils package on kepler. The buildroot build of bluez-utils has a sample audio/audio.conf. But it doesn't appear to get copied into the output/target tree. However, see RM #435. This file may need to be generated by the UI/cli tool.
   2. ALSA on Gentoo Wiki
9. PiBox also needs to configure an asoundrc file. See also the lightofdawn discussion, which is the best discussion of using BlueZ without pulseaudio (he's already "been down this rabbit hole"). He has additional discussion related to this and a2dp. Also, from RM #435, it seems we can use both the audio.conf and the asoundrc file with the latter generated by the UI/cli but the former static.

Notes¶

• GATT support is not enabled in Buildroot currently
• bluez-utils in Buildroot is BlueZ 4.101. BlueZ5 was added as a new package in Auguest 2014. However, since I already had bluez-utils enabled (for 4.x) I didn't see the new BlueZ5 package. So now I need to try that. Note that there are no patches against it that I would want since the Buildroot 2015.02 release.

Talked with Will (who did a lot of bluetooth stuff at his last job) and found that the dongle I'm using (from ModMyPi) is a Bluetooth 4.0 model. That means it supports both Bluetooth Classic and Bluetooth Low Energy. So it should work in my case. The fact that the JBL speaker beeps when I try to connect seems to verify that connection works. So this doesn't look like a Bluetooth problem.

• http://www.linuxfromscratch.org/blfs/view/svn/multimedia/alsa-lib.html
• http://www.linuxfromscratch.org/blfs/view/svn/multimedia/alsa-utils.html
• http://www.alsa-project.org/main/index.php/Asoundrc
• There is an alsa bootscript in the LFS bootscripts package.
• Here is an alternate setup for alsa over bluetooth.
• Instructable for setting it up on Raspbian (some alsa commands that might be useful)
• Some helpful tips on the Archlinux forums

Ugh. omxplayer doesn't support Alsa.

I'm hoping this is old info. If not, I'll have to find a hardware analog-to-bluetooth converter board to stuff into the player box.

Update: It's not old info. To use omxplayer, I'd have to add an external bluetooth transmitter.

"VLC"http://intensecode.blogspot.com/2013/10/tutorial-vlc-with-hardware-acceleration.html might work as an alternative but it may require a lot of updates to the base platform.

This issue will no longer track audio playback over bluetooth. I've proven the bluetooth config will work for that. It's just omxplayer that doesn't support it.

So this issue will track getting bluetooth configured properly irrespective of whether the audio output from the video player is working. This is to support other bluetooth devices, such as input and IoT devices.

1. Integrate LFS bluetooth init script to base platform.
2. Integrate LFS ALSA init script to base platform.

That's it for now. A front end GUI will have to be developed later, but I'll need a use case for it other than video player audio output.

init scripts are installed. They need to be tested with a new image on SD.

Committed and pushed.

Basic bluetooth support is available now. Future bluetooth requirements will be tracked separately.

Closing issue.