cddaly

Hi Guys - I am wondering if anyone has wired their MP3 player to emulate a CD changer. I looked at a couple of CD changers (one a Nissan OEM made by Clarion and an aftermarket Alpine) and they both have serial communications going between the radio and the CD changer to switch tracks, display track time, etc. Has anybody done this? Figured out the command format? Any help would be appreciated. Thanks, Dave Daly

MP3Car.com

 

Richard91

http://www.phatnoise.com/

mccleanp

I too would like to emulate a CD changer, at the very least it would solve the problem of getting nice buttons and a display.

The Phatbox looks pretty good, and credit certainly does have to go to the designers. But most people on this site are interested in engineering their own solution, not just lifting an after-market device.

Does anyone have any info on the communications specification between CD changers and head units. I have a Kenwood head unit, so Kenwood info would be of most use to me. I had a look around the phatbox web site, but there were no technical details.

I am fairly confident, that given the pinouts and protocol details of the interface, I could come up with the necessary hardware and software.

Regards,
Paul

gizmomkr

Im working on trying to dig up some info.. I also have a kenwood head unit - KDC-515S

I wrote kenwood a leter, I doubt I will hear back...

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Gizmo-
Techonlogy on Wheels
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killfiend

i was just about to start a topic about this. i just got a jvc, and its gotta be possible.

gizmomkr

well, its definately possible, but geting that interface info from the Mfgr is going to be dificult, might even require licensing....fees...Etc.
Im not exactly sure

So far, Kenwood has been bad with responding to my requests.

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Techonlogy on Wheels
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jjohnson

I'm actually working on this right now, for a commercial product ( www.m2pc.com ). I am getting a Kenwood CD Changer and plan on using a scope and logic probe/analyzer to "peek" at the signals going to <-> from the CD changer and head unit. I plan on making a PIC module that connects to the parallel or serial port and talks to the head unit, so the car PC looks like a CD changer to the head unit.

All I know at this point is:

- The protocols are serial
- Each MFR has their own standard, so I would potentially need to "hack" each brand to discover its protocol.
- There are audio signal lines in the same cable for getting audio to the head unit -- useful for units with no line in or aux in jacks!


I'll keep y'all posted...

__________________
Jason Johnson
Yorba Linda, California
http://www.m2pc.com

M²PC Phase IV - *** PENDING ***

gizmomkr

I would deffinately buy that pic if/when you made one.

I have a scope, but am not well versed in using them. I also have access to a serial line data analyzer at work. let me know if there is anything I can do to help.

__________________
Gizmo-
Techonlogy on Wheels
http://www.hjnetworks.com/car

MP3Car.com

 

r0cket-

I've thought about this quite a bit too, but, lacking the resources, I haven't really done anything about it. I think it might be nice to have the elapsed time and track/playlist number of the current song displayed on the head unit, and use a character LCD for directory browsing and whatnot. Free up a little space on the LCD, and have the time display where you would normally expect it. But, using just the head unit for all that (like the phat-whatever.com guys are doing) seems pretty lame, not to mention ackward.

lifter

I have an old Alpine CD changer/head unit, and I have the pinout somewhere. If anyone really needs it just email me and I'll dig it up the link. Supposedly, the Alpine pinout is identical to the stock Acura Integra (not sure which years) changer. But like JJ said, 3 of the pins are regular old analog audio signals, one is power (12V I think), one is ground, and there is a bus data send and recieve. 9 pins total, I think - same as a serial port.

killfiend

if cd-text worked there would no need for an lcd. that would be nice.

r0cket-

CD-text or not, I can't imagine trying to sift through 30 gigs of MP3s on something like that.

Alives

I have the kenwood X915 ... I'd love to get one of those pic controllers! I bought the aux adapter...i was thinking about taking hte adapter apart to find where the wires go...the problem is that it knew it was an aux adapter and not a changer. probably some kinda digital line for the cd text / track number.

darkwingduck

Well i too have a kenwood system (old KRC-657RL).

i would would be interested in knowing how the kommunication works and any hack possiblities.

Alives: Whats tha partnumber on the Aux adapter, and if you figure out how its working i would shure like to know (use cassette input right now)

alon_na

Did you?
If you didn't, can you post what you have done until now????
Thanks
BMW 318Is

MP3Car.com