AUDIOCTL

AUDIOCTL is a minimal ALSA command-line helper for controlling the onboard microphone and speaker audio paths on Lichee-Jack.

It is designed for scripts, payloads, and automation, providing a stable abstraction over amixer control names used by the CV181x audio subsystem.

Features

• Control microphone capture volume
• Control speaker playback volume
• Mute / unmute microphone
• Mute / unmute speaker
• No background daemon
• Script-friendly and deterministic

Dependencies

• alsa
• amixer

These are included by default in the Lichee-Jack Debian image.

Audio Topology

Mic (Digital / ADC)
        │
        ▼
 ADC Capture Volume / Mute   (hw:0)
        │
        ▼
     ALSA
 
 
Speaker
        ▲
        │
 DAC Playback Volume / MUTE (hw:1)
        ▲
        │
     ALSA

• hw:0 → ADC (microphone capture path)
• hw:1 → DAC (speaker playback path)

Usage

AUDIOCTL <COMMAND> [VALUE]

Commands

Examples

Set Microphone Volume

AUDIOCTL MICVOL 12

Valid range: 0 – 24

Set Speaker Volume

AUDIOCTL SPKVOL 20

Valid range: 0 – 32

Mute / Unmute Microphone

AUDIOCTL MICMUTE
AUDIOCTL MICUNMUTE

Mute / Unmute Speaker

AUDIOCTL SPKMUTE
AUDIOCTL SPKUNMUTE

Implementation Details

Internally, AUDIOCTL is a small shell script that wraps amixer cset calls:

• Microphone controls:

  • ADC Capture Volume
  • ADC Capture Mute

• Speaker controls:

  • DAC Playback Volume
  • DAC Playback MUTE

Explicit numeric ranges are enforced to avoid invalid ALSA states.

Design Notes

• No parsing of amixer output → predictable behavior
• Explicit hw:X selection avoids card index ambiguity
• Intended for payload scripts, mode switch hooks, and startup tasks

Integration Ideas

• Bind to Mode Switch positions
• Use in USB gadget payloads (HID + audio feedback)
• Combine with LED utilities for audio state indication

AUDIOCTL follows the Lichee-Jack philosophy: simple, explicit, and hackable.