This project is based on a powerful and energy-efficient STM32 microcontroller.
The microcontroller contains a Cortex-M4 core with floating point unit running at 180 MHz.
Serial audio bus has been connected to an Audio-DAC. TS4657 is a stereo DAC that integrates a high-performance audio line driver capable of generating a 2.2 Vrms output level from a single supply.
MPs files are stored on a memory card. OLED display is used to show information about track and to select MP3 file.
User controls the player using a simple keyboard with a few buttons (PLAY / STOP / PREV / NEXT / MENU / SELECT).

Components:
Flex PCB
STM32F427 Microcontroller
TS4657IQT stereo DAC
Memory card slot
Micro-USB connector for data transmission
Mini jack connector
SSD1306 OLED 128x32 Display with I2C interface
Keyboard
Battery