Speakers?

Feb 9, 2019 - 4:12 PM

  • Greetings,

    The enchilada has some speaker connections, and 12V input for an onboard amplifier.

    Has anyone tried that? Do you have to supply 12V to use speakers?

    Of course I will have to source a different power supply if I am going to provide +12V as well as +5V.

    I did try hooking up a Bluetooth speaker but I just get bluez complaining about a missing protocol.

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  • +12V is needed to power the audio amp so a dual output PS would be the way to go. I haven't tried it myself, but it would seem that +12V and hooking up a pair of 8 Ohm (looks like 4 Ohm is the minimum allowable impedence) speakers and that's it. Of course and OS with the proper driver is also required.

    This post was edited Feb 11, 2019 04:00AM
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  • Thanks, different power supply and Speakers are on the way.

    I am assuming that the volume connectors are for a potentiometer, but I'll see if I can work it out.

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  • APi has two audio output stream paths. Most commonly used is the HDMI audio output, which is directly from the Atom CPU. There's also a tiled, deterministic digital audio coprocessor called XMOS which drives a TI Class-D audio amp. One big market for API has been kiosk/jukeboxes. Running at +12V, the TI chip produces about 5W/channel into a 4 ohm load. You can run it on 5V and get about 1.5W/channel. Or use only HDMI audio to save power.. The VOL control labels are just soft GPIO pins. You can use Linux to set the volume and the GPIO pins can be programmed for anything.

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  • Just FYI, I wanted my atomic pi audio to route out through the audio amp instead of HDMI.
    Added +12v power and two speakers.
    Confirmed audio was working with:
    $ sudo speaker-test -D hw:1,0 -c 2 -r 48000 -t sine
    (Default is LOUD!)
    Since I wanted this to be the default audio device, I edited
    $ sudo nano /usr/share/alsa/alsa.conf
    Look for 'defaults.ctl.card' and change these two lines to 1
    defaults.ctl.card 1
    defaults.pcm.card 1

    Then tested again using built-in wav file with aplay:
    $ sudo aplay /usr/share/sounds/alsa/Front_Center.wav

    I also had to add the userid atomicpi to the audio group
    $ sudo adduser atomicpi audio
    Log off /on to pick up the new group or reboot
    So now I don't need to use sudo for audio:
    $ aplay /usr/share/sounds/alsa/Front_Center.wav

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  • New copy of Lubuntu 18.10 Installed eemc /boot and /
    128G sd card on /home

    My plan is to make a Retro game console. I wish to use the speakers. I have a MeanWell RD-50A )both 5v and 12V

    Verified voltages (the 12 v is a tad low, but that should not be an issue). I have the whole enchilada breakout board . Connected speakers to the SPKR and SPKL.

    No sound. Checked using aplay -l
    3 devices (hdmi) (0,1,2)
    tried all 3 consecutively in sound test no sound of any of them .
    which other devices should i try?

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