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Audio Volume Initialization and Adjustment

scripts/setup_audio_volume.sh is used to set audio output mixer volumes to maximum on Luckfox Pico Zero.

Default Settings​

The script sets:

  • DAC HPMIX: 2/2 (100%)
  • DAC LINEOUT: 30/30 (100%)

Deploy Script​

scp scripts/setup_audio_volume.sh root@<device-ip>:/root/

After logging into the device, execute:

cd /root
chmod +x setup_audio_volume.sh
./setup_audio_volume.sh

Auto-Execute on Boot​

Method 1: /etc/rc.local​

Add before exit 0:

/root/setup_audio_volume.sh

Method 2: systemd service​

If the system uses systemd:

cat > /etc/systemd/system/audio-volume.service << 'EOF'
[Unit]
Description=Set audio volume to maximum
After=sound.target

[Service]
Type=oneshot
ExecStart=/root/setup_audio_volume.sh
RemainAfterExit=yes

[Install]
WantedBy=multi-user.target
EOF

systemctl daemon-reload
systemctl enable audio-volume.service
systemctl start audio-volume.service
systemctl status audio-volume.service

Method 3: Application startup script​

#!/bin/sh
/root/setup_audio_volume.sh
/path/to/your/app

Verification​

amixer sget 'DAC HPMIX'
amixer sget 'DAC LINEOUT'

Expected output:

  • DAC HPMIX: Mono: 2 [100%]
  • DAC LINEOUT: Mono: 30 [100%]

Manual Adjustment​

amixer sset 'DAC HPMIX' 2
amixer sset 'DAC LINEOUT' 30
alsactl store   # Optional, save ALSA settings

Relationship with audio_service Volume​

  • Mixer volume determines the hardware output upper limit;
  • audio_service_cli set-volume --volume N sets the logical volume 0..100 within the service;
  • If hardware mixer is too low, even if logical volume is 100, actual sound may still be quiet.