MIDI CW Keyer - Rust Implementation

Adruino

https://raw.githubusercontent.com/digistump/arduino-boards-index/master/package_digistump_index.json

ino

cd ~/Arduino/libraries/ git clone https://github.com/heartscrytech/DigisparkMIDI

A Morse code keyer with MIDI input and audio output, converted from Python to Rust.

Original Project

Based on midicwkeyer.py by Christoph Berg DF7CB.

Features

• MIDI input for paddle keying (dit/dah)
• Real-time audio tone generation (850 Hz)
• Automatic Morse code decoding and display
• Adjustable WPM (words per minute) via MIDI control change
• Cosine-ramped audio envelope for clean keying
• State machine-based iambic keyer logic

Building

cargo build --release

The compiled binary will be at: target/release/midicwkeyer

Running

cargo run --release

Or directly:

./target/release/midicwkeyer

MIDI Configuration

The program will list available MIDI ports and connect to the first one. You can modify the code to select a specific port.

Expected MIDI Messages

• Note 1 (On/Off): Dit paddle
• Note 2 (On/Off): Dah paddle
• Control Change 61 (0x3D): WPM adjustment (6-48 WPM)

Dependencies

• midir - MIDI input handling
• cpal - Cross-platform audio I/O

Cross-Compilation to Windows

From Linux, you can build for Windows using MSVC (recommended) or MinGW:

# Build for Windows with MSVC (RECOMMENDED - avoids antivirus issues)
cargo build --target x86_64-pc-windows-msvc --release
# Output: target/x86_64-pc-windows-msvc/release/midicwkeyer.exe (~365 KB)

# Alternative: Build with MinGW (may trigger antivirus false positives)
cargo build --target x86_64-pc-windows-gnu --release
# Output: target/x86_64-pc-windows-gnu/release/midicwkeyer.exe (~2.4 MB)

Why MSVC? MSVC-compiled binaries are smaller, use standard Windows libraries, and are much less likely to trigger antivirus false positives.

Prerequisites for Cross-Compilation

For MSVC (recommended):

1. Install xwin (downloads Windows SDK):

   cargo install xwin

2. Download MSVC SDK (one-time setup):

   xwin --accept-license splat --output ~/.xwin

3. Install LLD linker:

   sudo apt install lld  # Debian/Ubuntu
   sudo dnf install lld  # Fedora/RHEL

For MinGW (alternative):

1. Install MinGW cross-compiler:

   sudo apt install mingw-w64  # Debian/Ubuntu
   sudo dnf install mingw64-gcc mingw64-winpthreads-static  # Fedora/RHEL

2. Add Windows target to Rust:

   rustup target add x86_64-pc-windows-msvc  # For MSVC
   rustup target add x86_64-pc-windows-gnu   # For MinGW

The project includes .cargo/config.toml with all necessary linker configurations.

Building for Multiple Platforms

# Linux (native)
cargo build --release

# Windows MSVC (recommended - smaller, fewer AV issues)
cargo build --target x86_64-pc-windows-msvc --release

# Windows MinGW (alternative - larger, may trigger AV)
cargo build --target x86_64-pc-windows-gnu --release

Binaries Location

• Linux: target/release/midicwkeyer
• Windows (MSVC): target/x86_64-pc-windows-msvc/release/midicwkeyer.exe ✅ Recommended
• Windows (MinGW): target/x86_64-pc-windows-gnu/release/midicwkeyer.exe

Building for macOS

Option 1: GitHub Actions (Recommended)

The project includes a GitHub Actions workflow that automatically builds for macOS (both Intel and Apple Silicon).

Push to GitHub and the workflow will create binaries for:

• Linux x86_64
• macOS x86_64 (Intel)
• macOS aarch64 (Apple Silicon)
• Windows x86_64 (MSVC)

Artifacts are available in the Actions tab after each push.

Option 2: Native Build on Mac

If you have access to a Mac:

cargo build --release

Option 3: Cross-compile from Linux

See MACOS_CROSS_COMPILE.md for OSXCross setup (complex, not recommended).

Platform Support Summary

Platform	Build Method	Status
Linux x86_64	Native	✅ Working
Windows x86_64 (MSVC)	Cross-compile (xwin)	✅ Working
Windows x86_64 (MinGW)	Cross-compile (mingw-w64)	✅ Working
macOS x86_64 (Intel)	GitHub Actions	✅ Automated
macOS aarch64 (M1/M2/M3)	GitHub Actions	✅ Automated