MP3 player based on CW32

Project Description
Use Wuhan Xinyuan Semiconductor CW32 series MCU as the main control of a small MP3. Use CW32L series low-power chip.
If you like my project, please like and collect it, thank you! Next issue will launch more high-quality works
Bilibili UP host: Teacher Lei talks about electronics, QQ Q&A group 458720579 
 
Open source agreement
GPL3.0
 
Project related functions
Lithium battery power supply, TYPE-C interface charging, power display;
power management;
3.5mm audio output interface, no external speaker mode;
screen display: lyrics name, lyrics, power, etc.; can set the screen brightness and time for power management;
SD card is inserted, and it supports reading song information;
 
Project attributes
This project is the first public, and it is my original project. The project has not won any other competitions.
 
Project progress
: May 20, start drawing the schematic diagram;
May 23, draw the PCB;
May 27, complete the welding and start debugging the program;
June 15, complete the first version
; June 28, start the second version;
July 12, complete the whole
 
design principle;
 
Design framework
: The above figure shows the main system framework of the entire MP3. First, the battery provides 4.2V voltage to the power management, which is then converted into 3.3V and 1.8V voltage for the entire system.
The main control extracts the information in the memory card and converts it into binary and inputs it into the audio decoding chip (VS1053B), and displays the information on the OLED display. Independent buttons can be used to control information such as play and pause.
 
Design Difficulty
Low Power Consumption (Solution: The power supply uses the industry-leading charge pump step-down chip, and the chip uses the CW32L series low-power main control)
 
1. Main control The main
control uses CW32L031C8U6, ARM® Cortex®-M0+ 32-bit low-power microcontroller with 64K bytes of FLASH, 8K bytes of RAM, and a maximum main frequency of 48MHz. It supports up to 39 I/O interfaces, which completely surpasses STM32. It has a wide range of applications in aerospace and national defense and military,
and has a high cost-effectiveness. At the same time, you can apply for a development board for free. 2021 is the 20th anniversary of the establishment of CW. It is also a year for Xinyuan Semiconductor to accelerate high-quality development. It is also a major turning point in the transformation of listed companies from agency distribution to a dual-core strategy of chip design and agency distribution. In the future, the company will continue to move forward steadily,
specialize and strengthen in the field of chip research and development, and actively respond to and implement the country's great strategy of domestic substitution in the chip industry.
CW32 Ecological Community:
WeChat public account search: "CW32 Ecological Community" --> click to follow, you can apply for development boards and chips for free. Dear friends, use your creativity and imagination, work together to promote the development and development of CW32! ! !
 
2. Audio decoding chip
VS1053B is a high-performance audio codec module, supporting: MP3/WMA/OGG/WAV/FLAC/MIDI/AAC and other audio formats decoding, and supports: OGG/WAV audio format recording, supports bass and treble adjustment and EarSpeaker space effect settings, and is very powerful.
It includes a high-performance, patented low-power DSP processor core VS_DSP4, working data memory, 16 KiB instruction RAM and more than 0.5KiB data RAM for user applications and any fixed decoder to run together, serial control and input data interface, and up to 8 available general-purpose I/O pins.
 
3. Independent buttons
 
Independent buttons use light touch buttons and paddle buttons, which are ergonomic and very comfortable to press.
 
4. Power management
Power management uses the battery charging chip TP4054, which is a complete monolithic lithium-ion battery constant current/constant voltage linear power management chip. Its thin size and small outer packaging make it easy to carry. What's more worth mentioning is that TP4054 is specially designed for USB power supply specifications. Thanks to the internal MOSFET structure, no external resistors and blocking diodes are required in the application. During high energy operation and high peripheral temperature, thermal feedback can control the charging current to reduce the chip temperature. The 
power chip uses TX4310B, which is a low-noise, constant frequency (1.2MHz) switched capacitor voltage doubler. TX4310B generates a stable output voltage from 1.8V to 5V input. The small number of external components (one fast capacitor and two small bypass capacitors at VDD and VOUT) makes the chip very suitable for small battery-powered applications. The charge pump architecture maintains a constant switching frequency to achieve no-load regulated output and reduce output and input ripple. 
 
5. OLED display screen
OELD adopts 0.96 inch blue 128x64 pixel resolution monochrome 30PIN, main control chip SSD1315
 
 
6. External interface circuit
The external circuit has TF card slot, download interface and 3.5mm audio interface. Here we should note that TF card adopts SPI communication and uses 10K resistor for pull-up to ensure the stability of communication.
 
Software description
The program is relatively complex, using state machine and file system, adding low power mode after screen off, thanks to the excellent low power performance of our CW32L031 series, it can play music continuously for 12 hours.
We need to place the font file in the SD card, download it in the attachment of my project, and write it to the SD card through the card reader to work, otherwise it will prompt
 
the physical display
design precautions
 
when it is turned on. We must be extra careful when installing the shell. Violent installation may damage the dial button!
I put the music played at the same time in the attachment, you can download
 
other
demonstration videos by yourself: just upload the demonstration video as an attachment, the maximum attachment can only be 50M long, files larger than 50M can be placed on other network disks or video websites, just put the address link here
Project attachments: the works participating in the event must upload the project-related program attachments to the open source platform or personal code storage cloud, the maximum attachment supports 50M upload (please do not upload in the LiChuang workspace, there are restrictions)