nymea-plugins/pianohat

Pianohat on the Raspberry Pi 3

Make sounds work

In order to make the sounds work on the raspberry pi jack output you have to do following steps:

• Add the sound module to the default modules

    $ echo "snd-bcm2835" | sudo tee -a /etc/modules
  

• Run raspi-config

  • 7 Advanced Options
  • A4 Audio
  • 1 Force 3,5mm (headphone) jack

Install pulseaudio

$ apt update
$ apt install pulseaudio

Create the systemd service:

$ nano /lib/systemd/system/pulseaudio.service

Insert folowing lines

[Unit]
Description=PulseAudio Sound System
Before=sound.target

[Service]
Type=simple
ExecStart=/usr/bin/pulseaudio --daemonize=no --system --realtime --log-target=journal

[Install]
WantedBy=session.target

Configure pulseaudio for systemwide usage

$ nano /etc/pulse/client.conf

Add following configurations

...
default-server = /var/run/pulse/native
autospawn = no

Add all users to the pulseaudio groups

$ nano /etc/group

...
pulse:x:114:nymea,root
pulse-access:x:115:nymea,root

Finally reboot the system

Test audio

Make sure your master PCM volume is up. You can do that using

$ alsamixer

You shoudl see follwoing audio outputs:

$ aplay -L

default
    Playback/recording through the PulseAudio sound server
null
    Discard all samples (playback) or generate zero samples (capture)
sysdefault:CARD=ALSA
    bcm2835 ALSA, bcm2835 ALSA
    Default Audio Device
dmix:CARD=ALSA,DEV=0
    bcm2835 ALSA, bcm2835 ALSA
    Direct sample mixing device
dmix:CARD=ALSA,DEV=1
    bcm2835 ALSA, bcm2835 IEC958/HDMI
    Direct sample mixing device
dsnoop:CARD=ALSA,DEV=0
    bcm2835 ALSA, bcm2835 ALSA
    Direct sample snooping device
dsnoop:CARD=ALSA,DEV=1
    bcm2835 ALSA, bcm2835 IEC958/HDMI
    Direct sample snooping device
hw:CARD=ALSA,DEV=0
    bcm2835 ALSA, bcm2835 ALSA
    Direct hardware device without any conversions
hw:CARD=ALSA,DEV=1
    bcm2835 ALSA, bcm2835 IEC958/HDMI
    Direct hardware device without any conversions
plughw:CARD=ALSA,DEV=0
    bcm2835 ALSA, bcm2835 ALSA
    Hardware device with all software conversions
plughw:CARD=ALSA,DEV=1
    bcm2835 ALSA, bcm2835 IEC958/HDMI
    Hardware device with all software conversions

Finally test if the jack connected speaker works:

$ aplay /usr/share/sounds/alsa/Front_Center.wav