Sounds

SVITRIX uses the integrated passive buzzer in the Ulanzi TC001 to play monophonic RTTTL melodies.

Melodies Manager

The web interface includes a complete melodies manager in the Sound Tab:

Saved Melodies

List of all melodies stored in /MELODIES/:

• ▶ Play — plays the melody on the device
• ✎ Edit — loads the melody into the RTTTL editor
• ✕ Delete — removes the melody from the device

RTTTL Editor

Built-in editor to create and edit melodies:

Field	Description
Name	Filename (without extension)
Content	RTTTL melody code

Buttons:

• 🔊 Preview — plays the melody in your browser using Web Audio API (no device required)
• ▶ Play on device — sends the melody to the Ulanzi buzzer
• Save — saves the melody to /MELODIES/

Upload Melody

Upload melody files from your computer:

1. Select a .txt or .rtttl file
2. Preview the content
3. Preview locally before uploading
4. Upload to device

Playing Melodies via API

You can play RTTTL melodies in two ways:

Via API: Send the RTTTL string directly with your API request. See documentation for commands:

• Single sounds
• With your notification

Via file: This method avoids long JSON payloads since the receive buffer is limited. Go to the file manager in the web interface and create a new text file in the MELODIES folder. Name it whatever you like but use the .txt extension, e.g. alarm.txt. Inside the file, place a melody in RTTTL format. When referencing the sound file in API calls, omit the file extension.

RTTTL Melody Resources

You can find many melodies on the internet:

• Laub-Home Wiki: RTTTL Songs
• Online RTTTL player
• RTTTL editor

Volume Control

Volume controls the PWM duty cycle of the buzzer. Range: 0–30 (default: 25).

On-screen menu: Navigate to the VOLUME menu item on the clock. Use left/right buttons to adjust. Long-press select to save.

Via API:

# Set volume to 15
curl -X POST http://<ip>/api/settings -d '{"VOL": 15}'

# Get current volume
curl http://<ip>/api/settings

The volume setting is saved to flash and persists across reboots.

Sound Toggle

Sound can be enabled or disabled globally:

On-screen menu: Navigate to the SOUND menu item. Toggle with left/right buttons. Long-press select to save.

Via API:

{"SOUND": true}

When sound is disabled, all melody playback (notifications, boot sound, API calls) is muted. The volume level is preserved and restored when sound is re-enabled.