Tag Archives: BeagleBoard

PulseAudio Buffer Size Tests

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It has been a few weeks, but in my defense, I have been pretty busy testing and debugging in this new environment. As an assignee to the Linaro project, my first task was to figure out if increasing the buffer size would enable the ARM cpu to drop into a lower power state. Code investigation, community feedback and prototyping said probably not, but I followed through. Below is a chart showing all the testing done, including the recent work to go back through the tests with ALSA 1.0.24 in the stack to enable checking for  period disable. Enjoy!

PulseAudio Buffer Size Tests

PulseAudio Buffer Size Tests

Sound: BeagleBoard C4

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Here are my notes from the experimental process of learning how to get sound out of a Linaro image (Headless, ALIP, Netbook) and a BeagleBoard.

  • Plug amplified speakers into the 1/8″ jack closest to the s-video port – they must be amplified, signal is line level only
  • ALSA – Playback hardware devices:
    • card0: omap3beagle
    • device0: TWL4030
    • No regular simple controls like “Master” defined for BeagleBoard
  • Sounds installed in /usr/share/sounds
  • Test with aplay
  • By default, all sound outputs for ALSA are set to 0 and/or muted
  • Configure with alsamixer
    • Unmute HeadsetL and HeadsetR, turn volume up for “DAC2 Analog” ~50 and “DAC2 Digital Fine” ~50-75, and “Headset” to ~ 67 for best results, these are the only controls that change line-level output via the onboard jack
    • All controls listed must be turned up or no level is present at the jack
  • Pulseaudio – Successful playback of .wav with paplay, one dropout, quality fairly good

Linaro!

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My BeagleBoard

My BeagleBoard

It has begun! I officially started full-time on December 1st, and then shortly after went on vacation. I had started part-time around mid-November getting acquainted with everyone on the project and ordering my first development board. I ordered a BeagleBoard rev. C4 to get started. I quickly discovered that plugging and unplugging all the cables put them under a lot of stress, so, I created a very high-tech way of mounting the BeagleBoard with strain-relief cable ties on the serial plug. Yes, that is a double layer of cardboard with anti-stat foam under the board. Laugh all you want, it is light-weight, sturdy and very inexpensive. Here it is, isn’t it cute?