Hardware – MP3Player

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

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

On the first version, the musics control were made through three buttons (with two functions each) and the visualization were made with a LCD [picture].

On the second version, a numeric keyboard was created (by cutting the numeric portion of an old keyboard) to control the musics and the LCD was placed above the numeric keyboard [picture].

This project costed approximately US$ 120.00.


MPXPlay is the software to play the music files [picture]. 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 [download softwares].


The PC used was a Pentium 100MHz, 16MB RAM, 640MB Seagate hard disk, 16 bit Soundblaster board and a 250W Upson power supply. The hard disk was coated with foam to avoid shocks [picture].

The LCD (HD44780) [picture] 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 musics control from the car trunk to the front panel [picture]. A DC to AC Power Inverter (12V -> 110V – 80W) was used to power on the computer [picture].

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