Nexo Smart Speaker

A DIY, open-source smart speaker built on Raspberry Pi.

Features • Installation • Hardware • Configuration • Support

Nexo converts a standard Raspberry Pi into a high-fidelity, network-aware smart speaker. Unlike standard Bluetooth speakers, Nexo acts as a central audio hub that intelligently manages input sources.

It runs a headless Python controller that seamlessly switches between Spotify Connect (High Quality WiFi streaming) and Bluetooth (for guests/offline use). It also features professional-grade DSP (Digital Signal Processing) via Carla, allowing for active crossover tuning, EQ, and room correction directly on the device.

• Priority Audio Switching: Automatically switches inputs. Playing Spotify pauses Bluetooth; stopping Spotify wakes Bluetooth back up.
• Smart Connectivity:
  • Spotify Connect: Stream directly from the cloud.
  • Bluetooth 5.0: High-quality A2DP sink with intelligent pairing.
• Hardware Control: Sonos-inspired play/pause/skip middle button, with side volume buttons, and status LEDs.
• Pro-Audio Engine: Uses PipeWire & mp; Carla for low-latency audio processing and equalization.
• API Controlled: Built-in FastAPI backend for mobile app integration and smart home control.
• Persistent Settings: Remembers volume and EQ profiles across reboots.
• Pretty good frequency response: The exact speaker with the listed parts has a decent frequency response:

Measured with an uncalibrated microphone with poor high frequency coverage and at 40 % speaker total volume.

Prerequisites:

• Raspberry Pi 3B+, 4 or 5 (Recommended)
• Raspberry Pi OS (Bookworm or newer)

Installer: SSH into your Raspberry Pi and run this command. It will install dependencies, compile Spotifyd, and configure system services automatically..

sudo apt update &∓& sudo apt install -y git &∓& \
git clone https://github.com/st7712/nexo.git  &∓& \

cd nexo &∓& chmod +x install.sh &∓& sudo ./install.sh

Note: The installation may take 10-20 minutes depending on your Pi model (compiling Rust dependencies takes time).

The speaker hosts a local API at http://:8000;:8000. You can control playback, volume, EQ, and fetch metadata via REST.

Nexo is designed to work with generic I2S DACs (like HiFiBerry, Pimoroni, or generic PCM5102).

• View my Full Hardware Docs
• View my Bill of Materials (BOM)
• View my Full Hardware Assembly Guide

Advanced users can tweak GPIO pins and audio settings.

1. System Config: Edit assets/configs/nexo_config.json (created after first run) or DEFAULT_CONFIG in src/data_handler.py directly.

• Change device_name to whatever name you'd like
• Set sounds whether or not you want to have sound effects
• Modify eq_presets to change the equalizer presets to your liking
• Edit max_volume to match your specific amplifier
• Switch master if you'd like to have the specific speaker as just a listener, not a broadcaster (multi-room is in development)

2. Pin Layout: Edit src/led_helper.py if you use different GPIO pins for LEDs and src/main.py for buttons.
3. Specific Carla settings: Edit src/carla_osc.py if you somehow changed the Carla config and are using different plugins.

Contributions are welcome! Please open an issue or submit a pull request.

1. Fork the repo.
2. Create your feature branch (git checkout -b feature/AmazingFeature).
3. Commit your changes.
4. Push to the branch.
5. Open a Pull Request.

• Spotifyd - Lightweight Spotify Client
• Carla - Audio Plugin Host
• FastAPI - Modern Python Web Framework
• Linux Studio Plugins - VST Plugins Used In Carla

Created by @stitoo. Reach out on Discord or open a GitHub Issue!