Project

# Title Team Members TA Documents Sponsor
13 Modular and Affordable Digital Accordion
Guangyang Sun
Henry Zhang
Zhuoer Zhang
Jiankun Yang design_document1.pdf
final_paper1.pdf
other1.pdf
proposal1.pdf
video1.mov
Team Members:
- Guangyang Sun (gsun16)
- Zhuoer Zhang (zhuoer3)
- Hanyu Zhang (hanyu8)

# Problem

Traditional accordions are expensive, delicate instruments that require regular maintenance. Their sound quality is sensitive to environmental factors such as temperature and humidity, making them less reliable in varying conditions. Additionally, learning to play the accordion presents a steep learning curve, especially for beginners.

Currently, digital accordions on the market cost over $7,000, making them inaccessible to most entry-level players and hobbyists. These challenges highlight the need for an affordable, beginner-friendly, and modular digital accordion that can replicate the traditional instrument’s features while addressing its limitations.

# Solution

We propose to build a low-cost ($150 or less), modular, and beginner-friendly 12-bass digital accordion. Our design will replicate the sound and functionality of a traditional accordion using modern electronics while offering improved durability and ease of maintenance.

The solution will include the following subsystems:

1. Key Input Subsystem: Detects user inputs from bass buttons and treble keys.
2. Sound Synthesis Subsystem: Generates high-quality accordion sounds using a microcontroller.
3. Output Subsystem: Delivers audio through wired and optional Bluetooth connectivity.
4. (Optional) User Interface Subsystem: Offers optional features such as LED backlit keys, playback, lazy mode, and sound customization.

The system will detect key presses via a matrix scanning technique, process the input in the microcontroller to synthesize accordion sounds using a MIDI sound bank, and output the audio through wired or Bluetooth connections.

# Solution Components

## Subsystem 1: Key Input

This subsystem is responsible for detecting treble key and bass button presses. A matrix scanning approach will minimize the GPIO usage while ensuring accurate detection.

Design:

Matrix Configuration: A 5x8 matrix (5 rows and 8 columns) will be used to detect inputs from 26 treble keys and 12 bass buttons.

Components:

- Tactile push buttons (low-cost option) or capacitive touch sensors (for enhanced user experience).
- GPIO pins on the micro controller for interfacing with the matrix.

Key Features:

- Accurate key press detection with minimal input lag.
- Scalable design for modularity.

## Subsystem 2: Sound Synthesis Subsystem

This subsystem synthesizes high-quality accordion sounds in real time based on user inputs.

Design:

- Use a MIDI sound bank with pre-recorded accordion samples to replicate authentic sounds.
- Generate polyphonic sounds by combining waveforms for multiple notes.
- Utilize built-in DAC for waveform generation or an external DAC for higher audio quality.

Components:

- Microcontroller with DSP and DAC capabilities.
- External DAC for better audio quality.
- Flash memory or SD card to store sound samples and MIDI files.
- Optional: Low-pass filter for improved audio output.

## Subsystem 3: Output Subsystem

This subsystem delivers audio to external devices through both wired and wireless methods.

Design:

- Wired Output: A 3.5mm audio jack with an amplifier will support headphones or external speakers.
- (Optional) Bluetooth Output: Integrate Bluetooth streaming for wireless audio playback.

Components:

- Audio amplifier.
- 3.5mm audio jack and connectors.
- (Optional) Bluetooth module.

## Subsystem 4: (Optional) User Interface
This subsystem adds additional functionality to enhance user experience.

Features:

- LED Backlit Keys: Guide beginners in learning to play.
- Playback Mode: Replay user performance or pre-recorded songs.
- Lazy Mode: Random button presses play pre-recorded high-quality accordion sounds.
- Sound Customization: An LED display and interface allow users to change sound profiles or remap keys.

Components:

- RGB LEDs for backlit keys.
- Small OLED or TFT screen for the user interface.
- Additional GPIOs for expanded functionality.

# Criterion For Success

Our project will be considered successful if it meets the following testable criteria:

1. The system can detect treble and bass key presses accurately with no noticable input lag.
2. The sound synthesis subsystem generates high-quality accordion sounds with minimal distortion.
3. Audio output is clear and functional through wired connection.
4. The system is modular, with components that can be easily replaced or repaired.
5. The total cost of materials stays below $150.
(Optional features can be added to the project, such as LED backlit keys, playback, lazy mode, and bluetooth, if time permits)

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