System Config

System Configuration

If you don't have the BrainPack, you can skip this section.

Screen Animation Service

To enable the screen animation service, install unclutter first to hide the mouse cursor:

sudo apt install unclutter

Then, add the script to /usr/local/bin/start-kiosk.sh and make it executable:

#!/bin/bash

unclutter -display :0 -idle 0.1 -root &

HOST=localhost
PORT=4173

# Wait for Docker service to listen
while ! nc -z $HOST $PORT; do
  echo "Waiting for $HOST:$PORT..."
  sleep 0.1
done

# Launch with autoplay permissions
exec chromium \
  --kiosk http://$HOST:$PORT \
  --start-fullscreen \
  --disable-infobars \
  --noerrdialogs \
  --autoplay-policy=no-user-gesture-required \
  --disable-features=PreloadMediaEngagementData,MediaEngagementBypassAutoplayPolicies \
  --no-first-run \
  --disable-session-crashed-bubble \
  --disable-translate \
  --window-position=0,0

Make it executable:

sudo chmod +x /usr/local/bin/start-kiosk.sh

Add the script to /etc/systemd/system/kiosk.service to launch the kiosk mode automatically on boot.

# /etc/systemd/system/kiosk.service
[Unit]
Description=Kiosk Browser
After=docker.service
Requires=docker.service

[Service]
Environment=DISPLAY=:0
ExecStart=/usr/local/bin/start-kiosk.sh
Restart=always
User=openmind

[Install]
WantedBy=graphical.target
Enable and start the service:

sudo systemctl daemon-reload
sudo systemctl enable kiosk.service
sudo systemctl start kiosk.service

Note: To stop the kiosk service, use sudo systemctl stop kiosk.service.

AEC Service

To enable the Acoustic Echo Cancellation (AEC) service, uninstall PipWire if it's installed and install PulseAudio

sudo apt remove --purge pipewire-audio-client-libraries pipewire-pulse wireplumber

Then install PulseAudio:

sudo apt install pulseaudio pulseaudio-module-bluetooth pulseaudio-utils pavucontrol

Next, stop the PipWire daemon and start the PulseAudio daemon if it's not already running:

systemctl --user mask pipewire.service
systemctl --user mask pipewire.socket
systemctl --user mask pipewire-pulse.service
systemctl --user mask pipewire-pulse.socket
systemctl --user mask wireplumber.service
systemctl --user stop pipewire-pulse.service
systemctl --user stop pipewire.service wireplumber.service
systemctl --user disable pipewire.service wireplumber.service
systemctl --user enable --now pulseaudio.service

Next, add the script to prevent PulseAudio from going into auto-exit mode.

mkdir -p ~/.config/pulse
cat > ~/.config/pulse/client.conf << 'EOF'
autospawn = yes
daemon-binary = /usr/bin/pulseaudio
EOF

# Create daemon config to disable idle timeout
cat > ~/.config/pulse/daemon.conf << 'EOF'
exit-idle-time = -1
EOF

Now, you can restart the system to ensure PulseAudio is running properly.

sudo reboot

[!Note] After reboot, if the audio devices are not automatically detected, you may need to manually start PulseAudio with the command:

systemctl --user restart pulseaudio

Now, you can add the script to /usr/local/bin/set-audio-defaults.sh and make it executable:

#!/bin/bash
set -e

sleep 5

# First, set the master source volume to 200%
pactl set-source-volume "alsa_input.usb-R__DE_R__DE_VideoMic_GO_II_FEB0C614-00.mono-fallback" 131072
pactl set-source-mute "alsa_input.usb-R__DE_R__DE_VideoMic_GO_II_FEB0C614-00.mono-fallback" 0

# Unload then load AEC module
pactl unload-module module-echo-cancel || true
pactl load-module module-echo-cancel \
  use_master_format=1 \
  aec_method=webrtc \
  source_master="alsa_input.usb-R__DE_R__DE_VideoMic_GO_II_FEB0C614-00.mono-fallback" \
  sink_master="alsa_output.platform-88090b0000.had.hdmi-stereo" \
  source_name="default_mic_aec" \
  sink_name="default_output_aec" \
  source_properties="device.description=Microphone_with_AEC" \
  sink_properties="device.description=Speaker_with_AEC"

# Wait a moment for the module to fully initialize
sleep 2

# Set defaults
pactl set-default-source default_mic_aec
pactl set-default-sink default_output_aec

# Retry volume setting until device appears and volume is set correctly
for i in {1..15}; do
  if pactl list short sources | grep -q default_mic_aec; then
    # Set volume to 200% (131072)
    pactl set-source-volume default_mic_aec 131072
    pactl set-source-mute default_mic_aec 0

    # Verify the volume was set
    CURRENT_VOL=$(pactl list sources | grep -A 7 "Name: default_mic_aec" | grep "Volume:" | awk '{print $3}')

    if [ "$CURRENT_VOL" = "131072" ]; then
      echo "Microphone volume successfully set to 200%"
      break
    else
      echo "Volume is $CURRENT_VOL, retrying... ($i/15)"
    fi
  else
    echo "Waiting for AEC source to appear... ($i/15)"
  fi
  sleep 1
done

# Final verification
pactl list sources | grep -A 7 "Name: default_mic_aec" | grep -E "Name:|Volume:"

Use the following command to get the list of audio sources and sinks:

pactl list short

Note:

Replace alsa_output.platform-88090b0000.had.hdmi-stereo with your speaker source and alsa_input.usb-R__DE_R__DE_VideoMic_GO_II_FEB0C614-00.mono-fallback with mic source

Make it executable:

sudo chmod +x /usr/local/bin/set-audio-defaults.sh

Create a systemd user service to run the script on login:

mkdir -p ~/.config/systemd/user
sudo vim ~/.config/systemd/user/audio-defaults.service

Add the following content:

[Unit]
Description=Set Default Audio Devices
After=pulseaudio.service
Wants=pulseaudio.service

[Service]
Type=oneshot
RemainAfterExit=yes
ExecStart=/usr/local/bin/set-audio-defaults.sh

[Install]
WantedBy=default.target
Enable and start the service:

systemctl --user daemon-reload
systemctl --user enable audio-defaults.service
systemctl --user start audio-defaults.service

Once you're done with above steps, you can proceed with OTA setup here