This might be a overkill subject but still.
I'm have had an idea to build my own cd player and stumbled upon some diy:ers that pick apart some old specific models cd player and build out of them.
the problem is that due that this blew up in the DIY audio scene the IC's that is used is either hard to find since they are obsolete or freaking expensive.
Now i wonder if there is any way to reverse engineer these chips to produce a digital output with an FPGA, or is it as "simple" as finding some other controller IC that is compatible with the CD-carrige that i have? or alternative 2 find some documentation that goes through how the signal and processing works ect.
anyone have any ideas?
it's a "For fun" project so keep that in mind before spamming "but why!?".
Many CD/DVD players have some kind of keyboard/display driver device located on the display panel. The "intelligence" on the main board communicates with this device using SPI (the main board is the "master", and the display is the "slave").
Create a device which emulates the SPI slave, and you get full control of the player - you can emulate key presses to control, and you can get data back to verify that your command has been received and acted on - you can close the control loop. You don't have to emulate the whole device (for example you can just read and ignore display information)
An alternative is to simply inject IR remote commands either by removing the IR receiver and wiring in your controller, or by making an infra-red transmitter. The downside of that approach is the lack of feedback - it's an "open loop" system.
A closed loop system is better - just because you pressed play and then pressed the "next track" button ten times doesn't guarantee that track 10 will actually be played (for example: a 9 track CD=no track 10, or a button press got missed=track 9 gets played instead, or track 10 gets selected but not played).