This project uses:

• Arduino Nano as development controller (supposed to be changed to Pro Mini 3.3v)
• DF Player Mini as a chip that has both SD card slot and MP3 player capability, but can't read file names on SD card
• SSD1306 OLED Display with resolution of 128x32

Also considered:

• Li-po battery of 300-400 mAh
• LTC4150 coulomb counter (might be overkill)
• Voltage regulator with USB port (18650 or TP4056)
• Almost special USB-Serial programmer to upload sketch with a tracklist of each folder

All hardware CAD files will be in it's specified folder named "hardware"