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

baton-studio 0.1.0