The Personal Blog of Mark Muzzin: Mega MP3

MEGA MP3 is a hard-drive based MP3 player with an LCD Display and Infrared Remote control. It is based on VLSI’s MPEG-3 decoder chip with built-in audio amplifier.

Features of Mega MP3:

Auto Play - Start automatically after power-on from last song.
Shuffle - Shuffle through either genre or entire song list.
Repeat - Repeat current song, or repeat song list.
FAT32 access allows easy "copy and paste" to the target drive.

The files are stored on a standard FAT32 hard-drive in subdirectories according to genre. The filename is composed of the Artist's/Group Name and Song Title. When the song begins, the LCD will display the genre, artist and title of the track (scrolling if larger than display width), song number, which features are enabled (i.e. (A)uto Play, (S)huffle Mode, (R)epeat Mode), elapsed time as a bar graph, and elapsed time in the format MM:SS. Here are a few screen shots of the LCD in various modes.

The storage capacity of the player is based on the size of hard-drive that you use, and the sample quality of the songs. Mega MP3 is currently fitted with a 6.2GB with CD quality sampling or better for each song. This drive has room to spare even with 1195 songs! At a average of 4min a song, that's more than 72 hours of music!

Controlling Mega MP3

Mega MP3 is controlled using a SIRCS (Sony Integrated Remote Control System) protocol based remote (in this case, my Sony Home Theatre remote).SIRCS/Control-S Protocol Description:The SIRCS protocol used by various Sony™ video products is simply a modulated version of Control-S protocol. Modulation is performed by the Remote control when transmitting a command. Its purpose is to aid the receiver by allowing it to "see" the signal clearer amongst ambient noise.

Modulation is accomplished by effectively "AND"ing the Control-S signal with the Carrier signal. De-Modulation takes place on the receiver side. This is done by detecting the presence (logic-1) or absence (logic-0) of the carrier signal.The Control-S command word is 12 bits long (other version of the protocol incorporate more), and consists of a 5-bit device ID code followed by a 7-bit button code:

The command word is preceded by a 2.4 ms logic-1 pulse (start bit) followed by 0.4 ms of logic-0. Each 1 bit in the control word is represented by a 1.2 ms logic-1 level followed by a 0.4 ms logic-0 level, and each 0 bit is 0.8ms high, 0.4 ms low:

The end of the control packet is always logic-0 level, and the total length of each packet is fixed at 45 ms in length. The bits in each control word are sent in increasing bit position order (i.e. low order bit first, high order bit last).

Above is a picture of the TV remote I used to control the features. With the device selector switch on DVD, the buttons behave appropriately for MEGA MP3. The DVD MENU Button is used to turn the Auto Play ON/OFFThe Arrow Up Button is used to turn the Shuffle Mode ON/OFFThe MENU button is used to turn the Repeat Mode ON/OFFRewind, Play, Fast Forward, Stop and Pause operate normallyHere is a picture of MEGA MP3 on the original proto board, you can see the SIRCS receiver mounted on top of the LCD display: