Many times, I share my idea in Thai journal book. Since 2002, I have used microcontroller based on MCS51, I think it is easy to begin and learn. Now a day, the semiconductor companies like microchip, analog device, Motorola etc, their build the solution with high performance device. There are so many types until I can’t study all at the same time, but intend to learn all step by step.
For this page, I can’t show my MCS51 project for this entire page, because long page. November 2004 and January 2005, this project was top hit. It is about recycle IDE-CDROM to play audio compact disc.
Overview
I see old ide cd-rom from second hand computer shop, the price is surprisingly cheap. I prompt the idea to recycle all these old CD ROM. I was thinking ‘what to say if u can make the player to use these old CDROM’. With the intention, I started to learn ATAPI and discuses with one of my good friend, “K.Sakda”. He gave me the circuit and some details for interfacing with CDROM. At the same time, I learn more documents regarding ATAPI. And make hardware for test.
Hardware
The CPU, I have two CPU on board, one CPU (AT89C52) connect direct to CDROM and one CPU (AT89C2051) control switch and get values from remote control. The bottom switches for stop, play, forward track, reverse track and etc. To make it user friendly, I make it compatible to the Sony remote control, which means you can use the Sony Audio infrared remote control to play this project.
Firmware
Based on AT89C52, Why I use that one, because I need internal memory more 128 Bytes. AT89C52 has 256 bytes RAM. This internal memory is used to store track information. One track consumes 3 bytes, so if Audio CD have 99 Track, it mean (99*3=297 byte), it seems like the memory is not enough, however, the normal audio CD is not over 50 tracks, they likely contain around 20 tracks. The remained RAM is used for the calculation variable storage like calculate remain time and etc.
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