The MP3 Garbler

Custom MP3 Player with LED Display

The MP3 Garbler is a custom MP3 player inspired by Lady Ada’s Minty MP3, designed with LED visualization, a USB interface, and an expandable control system.

While most DIY MP3 players of the time focused on simple playback, I wanted to create a more interactive system, featuring a matrix LED display and a modular interface for external device control.

Gallery

Gallery Icon

Features

  • VS1001K MP3 Decoder – Integrated DAC for audio playback
  • 140-LED Matrix Display – Controlled by a MAX6953 driver, enabling animations and visual feedback
  • USB Connectivity – Transfers MP3 files and allows communication with external devices
  • Expandable Interface – Designed to connect with external controllers, including Game Boy Advance

Design & Build

Hardware

The core MP3 functionality is handled by a VS1001K MP3 decoder, replacing the STA chip used in the original Minty MP3 design. Audio is output through a simple amplifier circuit, while a MAX6953 LED driver controls a 4x 5×7 LED matrix, providing visual animations synchronized with playback.

Instead of a complex button layout, the MP3 Garbler was designed with minimal onboard controls, relying on external devices for expanded functionality. A USB-to-TTL interface allows MP3 file transfers and control via a computer or embedded system. A planned feature included booting a Game Boy Advance into a custom interface for playlist management.

Software

The firmware is a modified version of Lady Ada’s Minty MP3 code, adapted to:

  • Control LED animations through the MAX6953 driver
  • Manage I2C communication for efficient display updates
  • Interface with the VS1001K decoder for playback

The LED matrix was repurposed beyond simple character display, allowing for custom pixel animations. One example included a skull & crossbones animation using direct binary pattern manipulation.

Reflections

Building the MP3 Garbler was a great exercise in hardware design, LED matrix control, and embedded audio playback. The integration of USB, I2C, and custom firmware expanded what was possible in a DIY MP3 player, allowing external device control beyond simple button presses.

This project was also my first experience with PCB design and surface-mount soldering, laying the foundation for future hardware projects.