MP3 Player

Back in 2003, a car MP3 player cost approximately US$ 500.00 here in Brazil. An amazingly high price for a student.

This project consists of an old PC in the car’s trunk, connected to the car’s audio system and playing MP3 files stored inside a hard disk.

On the first version, the music control were made through three buttons (with two functions each) and the visualization were made with a LCD. On the second version, a numeric keyboard was created (by cutting the numeric portion of an old keyboard) to control the music and the LCD was placed above the numeric keyboard.

This project cost approximately US$ 120.00.

SOFTWARE:
MPXPlay and some other softwares were used to play the music files. It already supports keyboard, remote control, lcd, joystick and mouse. The MPXF is a front-end to increase the visualization resources to be used with the LCD.

HARDWARE:
The PC used was a Pentium 100MHz, 16MB RAM, 640MB Seagate hard disk, 16 bit Soundblaster board and a 250W Upson power supply running MS-DOS. The hard disk was coated with foam to avoid shocks.

The LCD (HD44780) is connected to the parallel port and can display several kinds of information, for example: artist, title, album, genre, length, etc. A couple of trimpots were used to adjust the brightness and the contrast.

A 26-way cable was used to bring the lcd, backlight, leds, on/off button and music control from the car trunk to the front panel. A DC to AC Power Inverter (12V -> 110V – 80W) was used to power the computer.

On the initial version, the mouse buttons were used to control the music. A mouse was opened and the mouse buttons were replaced by real buttons on the car front panel. On the second version, a numeric keypad was cut from a complete keyboard and some reconnections were done to make it work again. The LCD was put where the numlock/capslock/scrolllock keyboard lights were before.