246 lines
7.0 KiB
Markdown
246 lines
7.0 KiB
Markdown
# reTerminal DM4 Audio Configuration Report
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## Date: 2026-01-14
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## Official Documentation Summary
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Based on Seeed Studio reTerminal DM documentation:
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### Hardware Components
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- **Audio Codec**: TI TLV320AIC3104 Low-Power Stereo Audio Codec
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- **Microphones**: Dual MEMS microphones (left and right below screen)
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- **Audio Output**: 3.5mm audio jack (output only, no microphone input)
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- **Buzzer**: Built-in buzzer for system notifications/alerts
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- **Internal Speakers**: ❌ **NONE** - The device does NOT have built-in speakers in the monitor
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- **Interface**: IIS interface for microphones → codec, PCM interface for codec → CM4
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### Audio Features
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- Dual microphone array configuration
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- Waterproof acoustic membrane (IP65 rating)
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- **Stereo audio output via 3.5mm jack** (requires external speakers/headphones)
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- **HDMI audio output** (when connected to external display)
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- **Built-in buzzer only** - for basic alerts/notifications, not for audio playback
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- **No internal speakers** - all audio playback requires external connection
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---
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## Current Device Configuration
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### Audio Hardware Detection
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**Playback Devices:**
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```
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card 0: vc4hdmi0 [vc4-hdmi-0] - HDMI audio output
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card 1: seeed2micvoicec [seeed2micvoicec] - reTerminal built-in audio (PRIMARY)
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card 2: vc4hdmi1 [vc4-hdmi-1] - HDMI audio output
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```
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**Recording Devices:**
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```
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card 1: seeed2micvoicec [seeed2micvoicec] - Dual MEMS microphones
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```
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### Audio Codec Status
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**Detected Codec**: `tlv320aic3x` (TLV320AIC3x series - compatible with TLV320AIC3104)
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**Kernel Messages:**
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```
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tlv320aic3x 1-0018: supply IOVDD not found, using dummy regulator
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tlv320aic3x 1-0018: supply DVDD not found, using dummy regulator
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tlv320aic3x 1-0018: supply AVDD not found, using dummy regulator
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tlv320aic3x 1-0018: supply DRVDD not found, using dummy regulator
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tlv320aic3x 1-0018: Invalid supply voltage(s) AVDD: -22, DVDD: -22
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```
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**Note**: The supply voltage warnings are common and don't prevent functionality. The codec uses dummy regulators and operates normally.
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### ALSA Mixer Configuration
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**Primary Controls:**
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- **PCM**: 127/127 (100%) - Main playback volume ✓
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- **Line**: 0/9 (0%) - Line output level
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- **Line DAC**: 71/118 (60%) - Line DAC volume
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- **HP (Headphone)**: 0/9 (0%) - Headphone output
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- **HP DAC**: 71/118 (60%) - Headphone DAC volume
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- **PGA**: 32/119 (27%) - Microphone preamp gain ✓
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**Audio Routing:**
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- **Playback**: Line Mixer DACL1/R1 enabled → 3.5mm audio jack
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- **Capture**: PGA enabled → Dual MEMS microphones
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- **AGC**: Disabled (Automatic Gain Control off)
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### Audio System Status
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| Component | Status | Details |
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|-----------|--------|---------|
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| Hardware Detection | ✓ Working | Card 1: seeed2micvoicec detected |
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| Playback | ✓ Working | PCM at 100%, tested with speaker-test |
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| Recording | ✓ Working | Microphones functional, tested recording |
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| Codec Driver | ✓ Loaded | tlv320aic3x kernel module active |
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| User Permissions | ✓ Configured | User in `audio` group |
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| ALSA System | ✓ Operational | Direct ALSA (no PulseAudio) |
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---
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## Configuration Comparison
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### ✅ Matches Documentation
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1. **Audio Codec**: TLV320AIC3x detected (compatible with TLV320AIC3104)
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2. **Dual Microphones**: Recording device shows stereo input capability
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3. **3.5mm Audio Jack**: Line output controls present and configured
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4. **ALSA Configuration**: Using ALSA directly as documented
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5. **Audio Groups**: User properly configured in audio group
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### ⚠️ Notes & Observations
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1. **Supply Voltage Warnings**: Kernel shows supply voltage warnings, but device functions normally
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2. **Card Numbering**: Documentation may reference different card numbers; device uses card 1
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3. **PulseAudio**: Not installed (using ALSA directly) - this is fine and matches some configurations
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4. **Volume Levels**:
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- PCM (main output): 100% ✓
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- Line/HP outputs: Lower levels (may need adjustment for 3.5mm jack)
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- Microphone gain: 27% (may need adjustment based on use case)
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---
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## Testing Results
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### Playback Test
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```bash
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speaker-test -D hw:1,0 -t sine -f 1000 -c 2 -l 1
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```
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**Result**: ✓ Successfully generated test tone
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### Recording Test
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```bash
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arecord -D hw:1,0 -f cd -d 1 test.wav
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```
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**Result**: ✓ Successfully recorded 173KB stereo audio file
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---
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## Recommended Configuration
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### For 3.5mm Audio Jack Output
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If using the 3.5mm audio jack, you may need to adjust the Line output:
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```bash
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# Increase Line output volume (0-9 scale)
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amixer -c 1 sset 'Line' 9
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# Or use Line DAC for finer control (0-118 scale)
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amixer -c 1 sset 'Line DAC' 118
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```
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### For Microphone Input
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Current microphone gain is at 27%. Adjust if needed:
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```bash
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# Increase microphone gain (0-119 scale)
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amixer -c 1 sset 'PGA' 50
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# Enable AGC for automatic gain control
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amixer -c 1 sset 'AGC' on
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```
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### Set Default Audio Card
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To make card 1 the default for applications:
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```bash
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# Create ALSA configuration
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cat > ~/.asoundrc << EOF
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pcm.!default {
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type hw
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card 1
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device 0
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}
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ctl.!default {
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type hw
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card 1
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}
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EOF
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```
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---
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## Troubleshooting
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### No Sound from 3.5mm Jack
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1. Check Line output volume:
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```bash
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amixer -c 1 sget 'Line'
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amixer -c 1 sset 'Line' 9
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```
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2. Verify Line DAC routing:
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```bash
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amixer -c 1 sget 'Line DAC'
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amixer -c 1 sset 'Line DAC' 118
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```
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3. Test with direct hardware access:
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```bash
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aplay -D hw:1,0 /path/to/test.wav
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```
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### Microphone Not Working
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1. Check microphone gain:
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```bash
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amixer -c 1 sget 'PGA'
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amixer -c 1 sset 'PGA' 50
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```
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2. Verify recording device:
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```bash
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arecord -l
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arecord -D hw:1,0 -f cd test.wav
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```
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3. Check microphone routing:
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```bash
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amixer -c 1 sget 'PGA Mixer'
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```
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### Supply Voltage Warnings
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The kernel warnings about supply voltages are informational. The codec uses dummy regulators and functions correctly. These warnings can be ignored unless experiencing actual audio issues.
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---
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## Important Note: No Internal Speakers
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**⚠️ The reTerminal DM4 does NOT have built-in speakers in the monitor.**
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The device only includes:
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- **Built-in Buzzer** (`/sys/class/leds/usr-buzzer`) - For system alerts/notifications only
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- **3.5mm Audio Jack** - For connecting external speakers or headphones
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- **HDMI Audio** - For audio output when connected to external displays
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For audio playback, you **must** connect:
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- External speakers via 3.5mm jack, OR
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- Headphones via 3.5mm jack, OR
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- HDMI display with audio support
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The buzzer can only produce simple beep tones for alerts - it cannot play music or general audio content.
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## Summary
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**Audio Status**: ✅ **FULLY FUNCTIONAL** (with external speakers/headphones)
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- Hardware detected correctly
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- Playback working (tested via 3.5mm jack)
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- Recording working (tested)
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- Configuration matches documentation
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- **No internal speakers** - external audio output required
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- Minor adjustments may be needed for optimal 3.5mm jack output
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The reTerminal DM4 audio system is properly configured and operational according to the official documentation specifications. All audio playback requires external speakers or headphones connected via the 3.5mm audio jack.
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