SynthBoard: Open-Source Audio Synthesizer 🎶

SynthBoard is a compact, open-source audio synthesizer designed to provide aspiring musicians with professional-grade sound generation capabilities. The project combines the flexibility of traditional synthesizers with the accessibility and modern design of illuminated grid-based controllers.

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🎯 Project Overview

Key Features:

• 4x4 Button Matrix: Allows real-time audio triggering with tactile feedback.
• RGB LED Integration: Individually addressable LEDs provide interactive lighting effects for enhanced user experience.
• Waveform Generation & Manipulation: Supports sine, square, triangle, and sawtooth waveforms with adjustable parameters.
• 8 Potentiometers: Provide precise control over volume, harmonic content, and ADSR envelope (Attack, Decay, Sustain, Release) settings.
• Audio Output: High-quality sound delivered through the STM32's integrated DAC and audio amplifier.
• Compact Design: A 3D-printed enclosure optimized for durability and functionality.

⚙️ Hardware Specifications

Components:

1. Microcontroller: STM32F407G-DISC1, chosen for its:
   • Built-in audio DAC for high-quality sound output.
   • Sufficient GPIO and ADC channels for matrix buttons and potentiometers.
   • SPI support for controlling WS2812B LEDs.
2. Buttons: A 4x4 tactile grid optimized with diodes to prevent ghosting.
3. LEDs: WS2812B LEDs in a daisy-chain configuration for efficient lighting control.
4. Potentiometers: 8 knobs for analog control of audio parameters, connected to ADC channels.
5. Enclosure: Designed and validated in Fusion360, featuring modular components and precise cutouts.

🛠️ Software Features

• Programming Environment: STM32CubeIDE using C++ for object-oriented implementation.
• Real-Time Control:
  • Audio synthesis based on additive principles and lookup tables for efficiency.
  • Adjustable parameters for harmonic generation and low-pass filtering.
• LED Control: RGB animations synchronized with button presses.
• Audio Buffering: Continuous playback via I2S protocol with interrupt-driven updates.

Code Structure:

• Oscillator Class: Handles waveform generation and harmonic synthesis.
• ADSR Envelope Class: Controls sound amplitude dynamics across Attack, Decay, Sustain, and Release phases.
• InputHandler: Manages button presses and potentiometer inputs for seamless interaction.
• Low-Pass Filter: Shapes sound frequency for smoother audio output.

📚 Documentation and Resources

• Project Report: Report (PDF)
• Demo Video: YouTube Link

📜 License

This project is licensed under the MIT License. See the LICENSE file for details.