Re: Writing software to control CD players

I would like to write my own software to control CD players. As much

as I am enjoying CDJ I have a need to support Pioneer home as well as

industrial CD jukeboxes. I also have my own 'player list' creator

that builds music lists for use at parties etc (DJ type work).

From what I can find on the Internet, I've read that you can control a

CD player (sony or pioneer) directly through a parallel port. It's my

understanding though that you have to send the commands as binary pulses

and that you have to control the duration of these pulses. For example

the sony is supposed to require a 2.4 ms start bit. Each logical 1 is

1.2 ms long, each 0 is .6 ms high, .6 ms low etc etc...

My first question(s) are.. 1) Is the above true.. that you have to control

the timing of these bit patterns in your software if you directly connect

a CD player. 2) Does it have to be a parallel port.. why can't it be a

serial port (I've read that a parallel port provides a TTL-level binary

output port.. If that's true how does this differ from a serial port ?)

It could be any port really. The problem is maintaining precise timing from a multitasking operating system without tying up all of the resources. This is why I made the Slink-e. It takes care of all of the timing related stuff so your programs can run more casually.

Assuming the above is true, I can see the pain and limitations of using

a parallel port and having to deal with this level of detail in the code.

Plus the inability to drive multiple players. (I guess you could drive

3 Sony's right ?)

3 per port x 4 ports = 12 players per Slink-e. You can run multiple Slink-es from my software though.

The Slink-e apparently allows you to issue Slink-e commands through a

serial port. The Slink-e then must translate these commands to the

'raw' binary and take care of the timing issues of sending these commands

directly to the players. Is this roughly correct ?

Yes

If I have 2 Pioneer CD players.. How would I use a Slink-e's IR capability

to independently control them. I don't think Pioneer supports unique

device addresses like the Sony's do. Would I have to use 2 Slink-e's ?

Put seperate IR transmitters on each player and isolate them from each other. Use seperate IR ports (the Slink-e has 8) for each player. The Pioneer does support some crude feedback info too. You could bring this info back via 2 of the 8 IR receiver port lines.

One final thought... (This is a test to see if Colby is still awake)

On the Nirvis home page it says that CDJ will support 48 CD players.

Since CDJ support's 8 serial ports or 8 Slink-e's x 12 CD players per

Slink-e shouldn't CDJ be able to support 96 CD players ?