baton-studio

A Rust library for controlling the Presonus STUDIO1824c USB audio interface.

Features

The Presonus STUDIO1824c is a professional USB audio interface that features:

• 18 input channels:

  • 8 analog input channels with mic/line/instrument preamps
  • 2 digital S/PDIF input channels
  • 8 digital ADAT input channels

• 18 DAW channels (output channels from the computer's perspective)

• 24 output channels:

  • 8 analog line output channels
  • 2 stereo headphone outputs (4 channels total)
  • 2 Main output channels
  • 2 digital S/PDIF output channels
  • 8 digital ADAT output channels

• Physical controls:

  • 48V phantom power button for mic inputs
  • Main output mute button
  • Main output mono button
  • Instrument/line level switch for channels 1 and 2

Mixer Architecture

The 1824c contains 9 separate internal mixes, each with stereo fader controls for all 36 input channels (18 physical inputs + 18 DAW channels):

• Mix 1: Main outputs (channels 1-2) + headphone output 1
• Mix 2: Line outputs 3-4 + headphone output 2
• Mix 3: Line outputs 5-6
• Mix 4: Line outputs 7-8
• Mix 5: S/PDIF digital outputs
• Mix 6-9: ADAT digital outputs (pairs 1-2, 3-4, 5-6, 7-8)

This library allows you to control:

• 72 input faders (36 channels × 2 for left/right)
• 9 stereo output faders (one per mix)
• 4 front panel buttons

Installation

Add this to your Cargo.toml:

[dependencies]
baton-studio = "0.1.0"

Quick Start

use baton_studio::*;
use nusb::MaybeFuture;
use std::error::Error;

fn main() -> Result<(), Box<dyn Error>> {
    // Find and open the device
    let device = nusb::list_devices()
        .wait()?
        .find(|dev| dev.vendor_id() == 0x194f && dev.product_id() == 0x010d)
        .ok_or(std::io::Error::new(
            std::io::ErrorKind::NotFound,
            "STUDIO1824c not found",
        ))?
        .open()
        .wait()?;

    let mut command = Command::new();
    let mut state = State::new();

    // Enable phantom power
    command.set_button(Button::Phantom, true).send(&device)?;

    // Set input fader for channel 1 to -3dB
    command
        .set_input_fader(0, 0, Channel::Left, Value::DB(-3.0))
        .send(&device)?;

    // Set main output fader to -2.4dB
    command.set_output_fader(0, Value::DB(-2.4)).send(&device)?;

    // Poll current state and read meter values
    state.poll(&device)?;
    let mic_level = gain_to_db(state.mic[0]);
    println!("Mic 1 level: {:.1} dBFS", mic_level);

    Ok(())
}

API Overview

Commands

The Command struct allows you to control the device:

let mut command = Command::new();

// Control input faders (channel, mix, left/right, value)
command.set_input_fader(0, 0, Channel::Left, Value::DB(-6.0)).send(&device)?;
command.set_input_fader(0, 0, Channel::Right, Value::Unity).send(&device)?;

// Control output faders (mix, value)
command.set_output_fader(0, Value::DB(-3.0)).send(&device)?;
command.set_output_fader(1, Value::Muted).send(&device)?;

// Control buttons
command.set_button(Button::Phantom, true).send(&device)?;
command.set_button(Button::Mute, false).send(&device)?;

State Monitoring

The State struct provides access to meter readings and button states:

let mut state = State::new();
state.poll(&device)?;

// Read input meters (dBFS values)
println!("Mic 1: {:.1} dBFS", gain_to_db(state.mic[0]));
println!("Line 1: {:.1} dBFS", gain_to_db(state.line[0]));
println!("DAW 1: {:.1} dBFS", gain_to_db(state.daw[0]));

// Read output meters
println!("Main L: {:.1} dBFS", gain_to_db(state.bus[0]));

// Read button states
println!("Phantom power: {}", state.phantom);
println!("Mute: {}", state.mute);

Signal Flow

The signal routing works as follows:

          +-->Fader left--->\                /-->Line Output 1
Input 1-->|                  |Stereo fader 1|
          +-->Fader right-->/                \-->Line Output 2
          |
         ...
          |
          +-->Fader left--->\                /-->ADAT Output 7
          |                  |Stereo fader 9|
          +-->Fader right-->/                \-->ADAT Output 8

Each of the 36 input channels can be routed to all 9 output mixes with independent left/right fader control.

Hardware Requirements

• Presonus STUDIO1824c USB audio interface
• USB connection to your computer
• Proper USB permissions (you may need to run as root or configure udev rules on Linux)

Examples

See the examples/ directory for more complete usage examples:

Testing

The library includes comprehensive tests:

# Run all tests (requires connected STUDIO1824c)
cargo test

Platform Support

This library should work on any platform supported by the nusb crate:

• Linux
• macOS

License

This project is licensed under the MIT License - see the LICENSE file for details.

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

Acknowledgments

• Built on top of the excellent nusb USB library
• Inspired by the need for programmatic control of professional audio equipment