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DAC Raspbian Pi2 and A2DP

vitalic

March 01, 2015 15:19

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Hallo,

i'd like to use my Pi2 as car pc. At the moement i got problems routing the sound from my phone via bluetooth through the pi to the DAC into the car speakers.

Playing the sound via the 3.5 jack is no problem.

I installed the A2DP like it is described here:

http://www.instructables.com/id/Turn-your-Raspberry-Pi-into-a-Portable-Bluetooth-A/?lang=de&ALLSTEPS

Whatt has to be changed, to rout the sound via the DAC ?

DAC is working. Playing mp3 from the pi is no prblem, only the bluetooth sound is a problem.

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6 comments

• 0
  
  Chris Mullen March 01, 2015 15:43

  You have to check with Daniel HiFiBerry support team but their products have there own analog sound output signal terminals/connectors.
  
  By wanting bluetooth output from HiFiBerry products you would need to convert back into a digital signal, then transmit over the bluetooth protocol and have your car system convert the digital bluetooth signal back into analog again.
• 0
  
  vitalic March 01, 2015 18:24

  The normal output is working. When i start a mp3 i can listen to it via audio jack or hdmi.
  
  When the source is my phone an i play a mp3 via bluetooth to the pi, i can listen to it too via audio jack (didn't try hdmi).
  
  But i want to rout the signal from a bluetooth source not to the jack or the hdmi. It should be play via the DAC output.
  
  It must be an pulseaudio or alsa problem.
• 0
  
  vitalic March 01, 2015 19:57

  solved
  
  /var/lib/udev/bluetooth
  
  
  

  #!/bin/bash
  
  AUDIOSINK="alsa_output.platform-sound.analog-stereo"
  echo "Executing bluetooth script...|$ACTION|" >> /var/log/bluetooth_dev
  
  ACTION=$(expr "$ACTION" : "\([a-zA-Z]\+\).*")
  if [ "$ACTION" = "add" ]
  then
  
  # Turn off BT discover mode before connecting existing BT device to audio
  hciconfig hci0 noscan
  
  # Set volume level to 100 percent
  amixer set Master 100%
  pacmd set-sink-volume 0 65537
  
     for dev in $(find /sys/devices/virtual/input/ -name input*)
     do
        if [ -f "$dev/name" ]
        then
           mac=$(cat "$dev/name" | sed 's/:/_/g')
           bluez_dev=bluez_source.$mac
  
           sleep 1
  
           CONFIRM=<code>sudo -u pi pactl list short | grep $bluez_dev</code>
           if [ ! -z "$CONFIRM" ]
           then
              echo "Setting bluez_source to:  $bluez_dev" >> /var/log/bluetooth_dev
              echo pactl load-module module-loopback source=$bluez_dev sink=$AUDIOSINK rate=44100 adjust_time=0 >> 
  
  /var/log/bluetooth_dev
              sudo -u pi pactl load-module module-loopback source=$bluez_dev sink=$AUDIOSINK rate=44100 adjust_time=0 
  
  >> /var/log/bluetooth_dev
           fi
        fi
     done
  fi
  
  if [ "$ACTION" = "remove" ]
  then
  # Turn on bluetooth discovery if device disconnects
  sudo hciconfig hci0 piscan
  fi
  

  
  
  
  now i can stream music via bluetooth from my handy through the hifiberry dac
• 0
  
  HiFiBerry team March 02, 2015 06:31

  Hi,
  
  thank you for this information. Some users have reported high CPU load with PulseAudio and bluetooth. What is the CPU usage by PulseAudio in your setup?
  
  Best regards
  Daniel
• 0
  
  vitalic March 04, 2015 18:36

  CPU usage is betwenn 15 - 17 % (Raspi 2)
• 0
  
  HiFiBerry team March 04, 2015 18:46

  Thank you for the feedback.
  
  Daniel