Melody Walker - First Prize Winner of the 2024 Embedded Systems Competition - RTT Track

Note: This page currently only displays the hardware; the code is not shown. Links will be provided after the software is refactored and improved.
Team Introduction
: Team: LORD;
Members: 3 first-year undergraduate students; Project
Description:
Music enthusiasts often struggle to find readily available sheet music when learning to perform. Manual transcription is time-consuming, laborious, and has a high barrier to entry. To solve this problem, our team developed an automatic sheet music transcription system based on the CH32V307VCT6 and STM32F103ZET6 chips on the RT-Thread operating system platform. Through spectrum analysis, it translates ambient sounds into musical notes on the staff in real time, visualizes them, and achieves the effect of automatic transcription.
Keywords: RT-Thread, RISC-V, ADC, FFT, spectrum analysis, task scheduling, TCP server, minimum system board, battery management;
Project Functionality

: Identifies the pitch of ambient sounds, displays the corresponding keys on a piano keyboard, and displays the musical notes on the staff.
Ambient sounds are plotted as spectrum bars.
The transcription results are uploaded to a TCP server and saved to the computer.

The product comprises
a self-designed PCB, a 4-inch TFT capacitive touchscreen, a MAX9814 microphone module, and a 3D-printed shell.
Key features include:

RT-Thread Operating System: Task scheduling and allocation for rapid recognition and high frame rates; RT-Thread Studio development using USART, I2C, and SPI software packages;
Cloud Computing: The product supports connection to a cloud server and uploading transcription results, achieved by a CH32 controller controlling an ESP8266 to send data packets to a cloud TCP server, recording the pitch and start/end times of each note;
User-Friendliness: Capacitive touchscreen with a full-color UI design, featuring pause and upload buttons for user interaction;
Battery Display: Four LEDs, color-changing from red to green, corresponding to 25%, 50%, 75%, and 100% battery level;
Convenient Power Supply: Main power source is a single 16340 battery, supporting Type-C charging, battery replacement, and external Type-C power supply;
Circuit Protection: Battery-side toggle switch, one fuse, and two TVS switches.

The following are

the unused parts of the PCB (V2 version): Two I2C pull-up resistors are not soldered (the touch module has already been pulled up), the 3V3, 5V, and GND reserved busbars in the upper left corner are not soldered, and the reserved IO in the upper right corner is not soldered.
Unverified software parts: ETH Ethernet (network port).
The open-source software released here (on the LCSC open-source platform) is more geared towards hardware design references, such as CH32V307 system board design, power supply design for small IoT products/competition projects, and the way to bring up debug ports/reserved IO for competition projects. Detailed software information is available on GitHub, and the link will be provided later.
As for why the V2 version PCB has an additional STM32, it's because the product initially used an ARM-based FFT (Fast Fourier Transform) assembly language library, and no similar library files were found for the CH32V307's RISC-V architecture. Due to the rushed preparation for the competition, this choice was made to run the FFT on the STM32; all subsequent work will be done on the CH32.

The document describes the following components
within the project:

CH32V307 motherboard first version PCB;
CH32V307_V2 motherboard second version PCB, also the final competition version;
ESP8266 sub-board, for board-to-board connection with the motherboard. Attachments include:

Shell_V2.rar (shell modeling file adapted for V2 version PCB);

and actual PCB photos.