MIDI Van

A Rust application that downloads random classical piano MIDI files from piano-midi.de and plays them through USB-connected MIDI devices.

Use Case

I have a Yamaha P71 keyboard that sounds great, and I wanted to explore the possibilities of playing classical piano pieces on it. Like a rust based player piano.

AI-Assisted Development

Most of this codebase were generated with the assistance of ClaudeCode during development. I wanted to try out this idea.

Features

• Downloads and caches MIDI files from piano-midi.de
• Supports all major classical composers (Bach, Mozart, Beethoven, Chopin, etc.)
• Random playback of classical piano pieces
• Cross-platform support (macOS and Raspberry Pi)
• USB MIDI device output
• Command-line interface with device selection

Requirements

• Rust 1.70+ (2024 edition)
• USB MIDI cable/interface
• MIDI-compatible piano or synthesizer

Installation

cargo build --release

Usage

List available MIDI devices

./target/release/midi-van --list-devices

Start random playback (auto-select device if only one available)

./target/release/midi-van

Specify a specific MIDI device

./target/release/midi-van --device "USB MIDI Interface"

Use custom cache directory

./target/release/midi-van --cache-dir /path/to/cache

Cross-compilation for Raspberry Pi

From macOS to Raspberry Pi (ARM64)

1. Install the target:

rustup target add aarch64-unknown-linux-gnu

2. Install cross-compilation tools:

brew install aarch64-elf-gcc

3. Configure Cargo for cross-compilation by creating .cargo/config.toml:

[target.aarch64-unknown-linux-gnu]
linker = "aarch64-linux-gnu-gcc"

4. Build for Raspberry Pi:

cargo build --release --target aarch64-unknown-linux-gnu

Alternative: Using cross

Install cross for easier cross-compilation:

cargo install cross
cross build --release --target aarch64-unknown-linux-gnu

Raspberry Pi Setup

1. Copy the compiled binary to your Raspberry Pi
2. Install required system dependencies:

sudo apt update
sudo apt install libasound2-dev

3. Connect your USB MIDI cable to the Pi
4. Run the application:

./midi-van --list-devices
./midi-van

Troubleshooting

No MIDI devices found

• Ensure your USB MIDI cable is properly connected
• On Linux/Raspberry Pi, check that your user is in the audio group:

  sudo usermod -a -G audio $USER

• Verify the device is recognized:

  lsusb  # Should show your MIDI interface
  aconnect -l  # List ALSA MIDI connections

Network/Download issues

• Ensure you have internet connectivity
• The application caches downloaded files in ./midi_cache/ by default
• If downloads fail, try again as some files may be temporarily unavailable

Playback issues

• Verify your MIDI receiving device (piano/synthesizer) is set to receive on the correct channel
• Some MIDI files may have different channel configurations
• Try different MIDI files if one doesn't play correctly

Architecture

The application consists of several modules:

• midi_scraper.rs - Web scraping and MIDI file downloading
• device_manager.rs - MIDI device discovery and connection
• midi_player.rs - MIDI file parsing and playback with accurate timing
• main.rs - CLI interface and application coordination

Dependencies

• midir - Cross-platform MIDI I/O
• reqwest - HTTP client for downloading files
• scraper - HTML parsing
• midly - MIDI file parsing
• tokio - Async runtime
• clap - Command-line argument parsing
• rand - Random selection