Audio System
Lichee-Jack integrates a compact audio subsystem suitable for voice prompts, alerts, and basic audio playback/recording.
- Speaker: 10 × 10 mm round, 1 W, 8 Ω
- Microphone: Onboard 16‑bit digital MEMS microphone (on LicheeRV Nano)
- Audio Codec (ADAC):
cv181x-adac - Power Amplifier: AW8010AFCR (onboard)
Speaker & Amplifier
The onboard amplifier AW8010AFCR drives the internal speaker directly.
Typical characteristics:
- Supply voltage: 5 V
- Output power: ≈ 1 W @ 8 Ω
- Test condition:
VDD = 5 V, RL = 8 Ω, f = 1 kHz - Efficiency: ≈ 90%
Volume warning
Lichee-Jack uses a 1 W speaker. During testing, 100% playback volume is intended for 2 W speakers.
Do NOT set playback volume above 80%, otherwise long‑term use may:
- Cause audible distortion
- Damage the speaker
- Overheat the PA
Microphone
The LicheeRV Nano includes an onboard SMD MEMS microphone:
- Model: LMA2718T421‑OA5‑2
- Sensitivity: −42 dB
- Signal‑to‑Noise Ratio (SNR): 55 dB
When the capture volume is set to maximum (24), recording quality degrades significantly (clipping + noise).
Recommended capture volume: 20
ALSA Control
Audio input/output levels are controlled via ALSA.
Microphone (ADC)
amixer -D hw:0 cset name='ADC Capture Volume' <0-24>- Range:
0 – 24 - Recommended:
20
Speaker (DAC)
amixer -D hw:1 cset name='DAC Playback Volume' <0-32>- Range:
0 – 32 - Recommended max: ≤ 80% (~25)
Practical Recommendations
- Keep playback volume ≤ 80% for daily use
- Avoid maximum ADC gain when recording
- For voice prompts or system sounds, moderate volume provides the best clarity
- If external speakers are required, use an external amplified speaker instead of pushing the onboard PA
Summary
The Lichee-Jack audio system is optimized for low‑power, embedded audio use cases:
- Clean voice output
- Basic audio feedback
- Acceptable voice recording quality
Proper volume configuration is essential to maintain audio quality and hardware reliability.