{"id":495,"date":"2016-10-22T12:50:32","date_gmt":"2016-10-22T16:50:32","guid":{"rendered":"http:\/\/markwheeler.com\/wordpress\/?p=495"},"modified":"2016-10-22T12:50:32","modified_gmt":"2016-10-22T16:50:32","slug":"raspberry-pi3-503hta-tube-dac-and-usb-microphone","status":"publish","type":"post","link":"https:\/\/markwheeler.com\/?p=495","title":{"rendered":"Raspberry PI3, 503HTA Tube DAC and USB Microphone."},"content":{"rendered":"

I have a Raspberry Pi 3<\/a> with a 503HTA Hybrid Tube Amp<\/a> and a USB Microphone<\/a> attached. I am running a HiFiBerry preconfigured SD Card<\/a> image.<\/p>\n

My intent is to run a MPD server accessible via tablet app; in this case MPD Control<\/a> for Android. And also the Amazon Alexa<\/a> sample application.<\/p>\n

The only way I could get this to work was thru PulseAudio. Prior to doing any of this, make sure everything is up-to-date.<\/p>\n

\nsudo apt-get update\nsudo apt-get dist-upgrade\nsudo rpi-update\nsudo reboot\n<\/pre>\n
I have Raspbian Jessie configured for the Tube Amp with the following modifications:
\n1. In \/boot\/config.txt; comment out dtparam=audio=on. This disables the onboard audio. I added the following –<\/strong><\/p>\n
\n#dtparam=audio=on\ndtoverlay=pi3-disable-bt\ndtoverlay=hifiberry-dac\n<\/pre>\n
dtoverlay=pi3-disable-bt disables the onboard bluetooth which I believe is necessary for HiFiBerry DACs.<\/p>\n
2. In \/etc\/modules; I have the following lines –<\/strong><\/p>\n
\ni2c-dev\n#snd_bcm2835\nsnd_usb_audio\n#DAC Modules\nsnd_soc_bcm2708\nbcm2708_dmaengine\nsnd_soc_pcm5102a\nsnd_soc_hifiberry_dac\n<\/pre>\n
3. In \/home\/pi\/.asoundrc; I have the following –<\/strong><\/p>\n
\npcm.usb\n{\n    type hw\n    card Device\n}\npcm.external\n{\n    type hw\n    card sndrpihifiberry\n}\npcm.!default\n{\n    type hw\n    playback.pcm\n    {\n        type hw\n        slave.pcm \"external\"\n    }\n    capture.pcm\n    {\n        type plug\n        slave.pcm \"usb\"\n    }\n}\nctl.!default\n{\n    type hw\n    playback.pcm\n    {\n        type hw\n        slave.pcm \"sndrpihifiberry\"\n    }\n    capture.pcm\n    {\n        type plug\n        slave.pcm \"usb\"\n    }\n}\n# The following lines are constantly added at boot. I have no idea which process does\n# this, but it overrides the configuration above.\npcm.!default {\n\ttype hw\n\tcard 1\n}\n\nctl.!default {\n\ttype hw\n\tcard 1\n}\n<\/pre>\n
I don’t believe this step is needed when using PulseAudio, however, this .asoundrc config works if you are using a USB microphone and onboard audio out. You can determine the name of your DAC with ‘aplay -l’ from the command line. Replace sndrpihifiberry with ‘ALSA’<\/p>\n
4. Installing PulseAudio – My steps:<\/strong><\/p>\n
\nsudo apt-get install vlc\nsudo apt-get install pulseaudio\nsudo apt-get install pavucontrol\n<\/pre>\n
5. Installing MPD<\/strong><\/p>\n
\nsudo apt-get install mpd\n<\/pre>\n
Modify the \/etc\/mpd.conf with:<\/p>\n
\naudio_output {\n#       type            \"alsa\"\n        type            \"pulse\"\n        name            \"MPD PulseAudio Output\"\n        server          \"127.0.0.1\"\n}\n<\/pre>\n
You will probably also need to edit this file with your custom options. <\/p>\n
6. Modify \/etc\/pulse\/client.conf; uncomment autospawn=yes. Delete the ‘;’ before that line.<\/strong><\/p>\n
7. Modify \/etc\/pulse\/default.pa<\/strong><\/p>\n
\n### Network access (may be configured with paprefs, so leave this commented\n### here if you plan to use paprefs)\n#load-module module-esound-protocol-tcp\nload-module module-native-protocol-tcp auth-ip-acl=127.0.0.1\n#load-module module-zeroconf-publish\n<\/pre>\n
Uncomment the native-protocol entry and add ‘auth-ip-acl=127.0.0.1’ at the end
\nSome instructions say to uncomment the zeroconf line, but I left it as-is.<\/p>\n
8. Depending on which user runs MPD. These commands lets specific users to the PulseAudio groups.<\/strong><\/p>\n
\nsudo usermod -a -G pulse-access mpd\nsudo usermod -a -G pulse mpd\nsudo usermod -a -G pulse-access pi\nsudo usermod -a -G pulse pi\n<\/pre>\n
9. Boot into your Raspbian Desktop GUI. Open a terminal and start PulseAudio.<\/strong><\/p>\n
\npulseaudio -D\n<\/pre>\n
10. You should now be able to launch the PulseAudio Volume Control.<\/strong>
\n\"pac\"<\/a>

\nYou should see your DAC as an Output Device and your USB Microphone as an Input Device.<\/p>\n
11. Start your Alexa services per the instructions on their GitHub.<\/strong>
\nNote: The original errors I was getting from the ‘wakeWordAgent -e sensory’ were:<\/p>\n
\nwakeWordAgent: pcm.c:694: snd_pcm_close: assertion 'pcm' failed\"\nor\nwakeWordAgent: pcm.c:1046: snd_pcm_prepare: Assertion `pcm' failed.\n<\/pre>\n
12. Verify your MPD app.<\/strong><\/p>\n
In my experience, you must always start PulseAudio first from a terminal before Alexa or the MPD server will function properly. With these instructions, I was able to have output from MPD and also have Alexa listen and respond.<\/p>\n","protected":false},"excerpt":{"rendered":"
I have a Raspberry Pi 3 with a 503HTA Hybrid Tube Amp and a USB Microphone attached. I am running a HiFiBerry preconfigured SD Card image. My intent is to run a MPD server accessible via tablet app; in this case MPD Control for Android. And also the Amazon Alexa […]<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"footnotes":""},"categories":[6,8,9],"tags":[22,53,57,87],"class_list":["post-495","post","type-post","status-publish","format-standard","hentry","category-music","category-projects","category-raspberry-pi","tag-alexa","tag-hifiberry","tag-hybrid-tube-amp","tag-raspberry-pi"],"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/markwheeler.com\/index.php?rest_route=\/wp\/v2\/posts\/495","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/markwheeler.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/markwheeler.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/markwheeler.com\/index.php?rest_route=\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/markwheeler.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=495"}],"version-history":[{"count":0,"href":"https:\/\/markwheeler.com\/index.php?rest_route=\/wp\/v2\/posts\/495\/revisions"}],"wp:attachment":[{"href":"https:\/\/markwheeler.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=495"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/markwheeler.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=495"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/markwheeler.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=495"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}