BeatBridge

Bridge between Pioneer Pro DJ Link and Ableton Link — sync tempo, phase, and transport from CDJs/mixers to any Link-enabled application in real time.

Built on prodjlink-rs and ableton-link-rs, two native Rust implementations of their respective protocols.

What It Does

BeatBridge joins a Pioneer DJ Link network as a virtual CDJ, listens for tempo/beat/transport events, and relays them to the Ableton Link session. This lets you sync:

• CDJs → Ableton Live (or any Link app) — DJs control the tempo, Link follows ✅
• Link → CDJs — Link apps control the tempo, CDJs follow via tempo master + fader start ✅
• Bidirectional — Both directions active, last writer wins with echo-guard suppression ✅

Use Cases

• Sync Ableton Live sets to CDJ tempo for hybrid DJ/production performances
• Bridge DJ hardware to Link-enabled iOS/Android apps
• Clock-sync modular gear (via Link) to a DJ setup
• Run headless on a Raspberry Pi sitting on the DJ network

Quick Start

# Build
cargo build --release

# Run with defaults (CDJ→Link, quantum 4, device #5)
./target/release/beatbridge

# Specify network interface and sync mode
beatbridge --interface 192.168.1.100 --sync-mode master

# Use a config file
beatbridge --config beatbridge.toml

CLI Options

Flag	Default	Description
-i, --interface	auto-detect	Network interface IP for Pro DJ Link
--device-name	beatbridge	Virtual CDJ name on the DJ network
--device-number	5	Virtual CDJ device number (1–6)
-q, --quantum	4.0	Ableton Link quantum (beats per phase)
-s, --sync-mode	master	master (CDJ→Link), slave (Link→CDJ), bidirectional
--initial-bpm	120.0	Starting BPM when no CDJ is connected
-l, --log-level	info	Log level: trace, debug, info, warn, error
-C, --config	—	Path to TOML config file
--status-interval-ms	500	Status display refresh interval

Configuration File

Copy beatbridge.example.toml to beatbridge.toml and customize:

# Network interface IP for Pro DJ Link (auto-detect if omitted)
# interface = "192.168.1.100"

device_name = "beatbridge"
device_number = 5
quantum = 4.0
sync_mode = "master"
initial_bpm = 120.0
log_level = "info"

CLI flags override config file values.

Sync Modes

Master (CDJ→Link) — default

The DJ controls tempo. BeatBridge listens for beats from the Pro DJ Link tempo master and pushes tempo + phase to the Ableton Link session. Play/stop state is forwarded as Link transport.

Slave (Link→CDJ)

Link controls tempo. BeatBridge claims tempo master on the DJ Link network, then relays Link tempo changes via status broadcasts and transport changes via fader-start commands to CDJs on channels 1–4. CDJs in sync mode will follow the Link tempo.

Bidirectional

Both directions active — last writer wins. CDJ beats push tempo into Link; Link tempo changes push back to CDJs. Uses a 100ms echo guard to prevent feedback loops.

Status Display

BeatBridge prints a compact, single-line status that updates in place — ideal for headless operation:

  ▶ 128.0 BPM │ CDJ→Link │ Master: P1 │ Link: 2 peers │ Phase: [█░░░] │ ✓ synced

Running on Raspberry Pi

BeatBridge is designed to run headless on a Raspberry Pi connected to the same network as your DJ equipment.

Cross-compile for aarch64 (from macOS or Linux x86_64)

BeatBridge depends on cpal (via ableton-link-rs → rodio), which links against ALSA on Linux. Cross-compiling requires a cross-toolchain and the ALSA development libraries for the target architecture.

1. Install the Rust target

rustup target add aarch64-unknown-linux-gnu

2. Install the cross-toolchain

macOS (Homebrew):

brew tap messense/macos-cross-toolchains
brew install aarch64-unknown-linux-gnu

Linux (Debian/Ubuntu):

sudo apt install gcc-aarch64-linux-gnu g++-aarch64-linux-gnu

3. Obtain aarch64 ALSA dev libraries

The cpal crate requires libasound2-dev headers and libraries for the target. You can get these from a Raspberry Pi or by downloading the arm64 package:

Option A — Copy from the Pi:

# On the Raspberry Pi, install the dev package if not already present
sudo apt install libasound2-dev

# From your build machine, copy the required files
mkdir -p sysroot/usr/lib/aarch64-linux-gnu sysroot/usr/include
scp pi@<pi-ip>:/usr/lib/aarch64-linux-gnu/libasound.so* sysroot/usr/lib/aarch64-linux-gnu/
scp pi@<pi-ip>:/usr/lib/aarch64-linux-gnu/libasound.a sysroot/usr/lib/aarch64-linux-gnu/
scp -r pi@<pi-ip>:/usr/include/alsa sysroot/usr/include/

Option B — Download the arm64 .deb package directly:

mkdir -p sysroot
# Download the arm64 libasound2-dev package (check the Pi's Debian version)
apt download libasound2-dev:arm64 2>/dev/null || \
  wget http://ports.ubuntu.com/pool/main/a/alsa-lib/libasound2-dev_1.2.8-1build1_arm64.deb
dpkg-deb -x libasound2-dev_*_arm64.deb sysroot/

# You'll also need the runtime library
apt download libasound2:arm64 2>/dev/null || \
  wget http://ports.ubuntu.com/pool/main/a/alsa-lib/libasound2_1.2.8-1build1_arm64.deb
dpkg-deb -x libasound2_*_arm64.deb sysroot/

Option C — Use cross (easiest, requires Docker):

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

cross handles the entire sysroot and toolchain automatically via Docker. Skip to Deploy to the Pi if using this method.

4. Build

Point pkg-config and the linker at your sysroot and toolchain:

export CARGO_TARGET_AARCH64_UNKNOWN_LINUX_GNU_LINKER=aarch64-linux-gnu-gcc
export PKG_CONFIG_SYSROOT_DIR="$(pwd)/sysroot"
export PKG_CONFIG_PATH="$(pwd)/sysroot/usr/lib/aarch64-linux-gnu/pkgconfig"
export PKG_CONFIG_ALLOW_CROSS=1

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

The binary will be at target/aarch64-unknown-linux-gnu/release/beatbridge.

Tip: Add these settings to .cargo/config.toml to avoid repeating them:

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

Deploy to the Pi

# Copy binary and config
scp target/aarch64-unknown-linux-gnu/release/beatbridge pi@<pi-ip>:/usr/local/bin/
scp beatbridge.toml pi@<pi-ip>:/etc/beatbridge.toml

# On the Pi — install the ALSA runtime if not already present
ssh pi@<pi-ip> 'sudo apt install -y libasound2'

Or build natively on the Pi

# Install build dependencies
sudo apt install build-essential libasound2-dev

# Install Rust (if not already installed)
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

# Build
cargo build --release

Run as a systemd service

Create /etc/systemd/system/beatbridge.service:

[Unit]
Description=BeatBridge Pro DJ Link ↔ Ableton Link
After=network-online.target
Wants=network-online.target

[Service]
Type=simple
ExecStart=/usr/local/bin/beatbridge --config /etc/beatbridge.toml
Restart=on-failure
RestartSec=5

[Install]
WantedBy=multi-user.target

sudo systemctl enable beatbridge
sudo systemctl start beatbridge
sudo journalctl -u beatbridge -f  # view logs

Architecture

┌─────────────────┐         ┌──────────────┐         ┌─────────────────┐
│  CDJ-3000 / NXS2│◄───────►│              │◄───────►│  Ableton Live   │
│  DJM-A9 / V10   │ Pro DJ  │  BeatBridge  │ Ableton │  iOS/Android    │
│  Opus Quad      │  Link   │              │  Link   │  Modular gear   │
└─────────────────┘  (UDP)  └──────────────┘  (UDP)  └─────────────────┘
                              │            │
                         prodjlink-rs  ableton-link-rs

Modules

• config — CLI args (clap) + TOML config file parsing
• bridge — Core sync engine with three modes (master/slave/bidirectional)
• status — Compact terminal status display with phase visualization
• main — Bootstrap, service wiring, and graceful shutdown

Supported Hardware

Any Pioneer DJ equipment supported by prodjlink-rs:

• CDJ-3000, CDJ-2000NXS2, CDJ-2000NXS, XDJ-XZ, XDJ-1000MK2
• DJM-A9, DJM-900NXS2, DJM-V10
• Opus Quad
• Any Ableton Link-compatible application (Live, iOS apps, etc.)

License

MIT