cauf

Sorry,
It has to be tape connector of course.

jdaled

I came across this wiring harness a while ago, and just found it again... it seems like it might be something useful. Maybe one of you electrical engineer types could check it out?

Go here: http://www.soundlinx.co.uk/, then put "mazda" in the search field.

eXentric

At first glance, I don't think those will be very usefull because they appear to intercept the audio between the head unit and the amplifier.

Although this *could* be used on the BOSE system, it would bypass the head-unit all together (which we don't want to do). Not to mention the base system doesn't have an external amplifier and an external MP3 player wouldn't have enough volume to drive the speakers directly.

Thanks for the links though. Any tech tidbits help.

eXe

Wingnut

I had been following this thread with interest but it appears to have died with the beginning of OverLoad's adapter thread. Though that is very interesting, it doesn't seem to add to the knowledge of what is going on and how to crack the nut. So I opened up my Bose w/6CD changer to do the CD AUX-IN hack that ectomort showed. I couldn't stop pulling things apart so I decided to take a closer look at the guts. Below is the hardware that I found and links to the datasheets for the chips. I can provide pictures, but all they really show are the chips I list below. For now I want to get my car back up and running with my XM radio tied into the CD AUX-In hack so I am putting it back together except I may also run a couple of wires to a few connectors for SYS MUTE and BUS+ and BUS- to later take a look at what is going on.

This is the heart of the system it includes the display protocols and CAN bus information as well:
Fujitsu Proprietary 16-bit Microcontroller (Chip Labeled MB90549G):
http://www.fma.fujitsu.com/pdf/e713703.pdf


ST Digitally Controlled Audio Processor (Chip Labeled TDA7437):
http://www.st.com/stonline/books/pdf/docs/4290.pdf

Sanyo PLL Frequency Synthesizer for Electronic Tuning (Chip Labeled LC72135):
http://service.semic.sanyo.co.jp/sem...e/LC72135M.pdf

JRC Dual High Current Op Amp (Chip Labeled 4556A):
http://www.njr.co.jp/pdf/ae/ae04051.pdf

The only other device I saw was what I presume is a crystal oscillator at 7.2000MHz.

There was discussion before about differential inputs, etc. but I think the inputs are just line level. I think the L+ and L-/ R+ and R- are really just meaning L in and L out... This only appears on the 16 pin connector on the back. The other internal 15 pin connector between the CD player and Bose just has line level L, R, and signal ground. I presume the same for the same 15 pin tape connector on the bottom. Labeled on th PC board for the 15 pin connector from Bose to CD is:

L
...............S GND
R
...............SYS MUTE
ACC
...............TEXT DO
TEXT CL
...............NC
EJECT
...............P GND
P GND
...............+B
+B
...............BUS GND
BUS+

Similar to cauf's diagram but maybe explains why a probe read +5V on one pin and GND on several others.

Hope this helps spur someones interest.

Wingnut

Edit:
Also, the only chip on the CD palyers pc board that has the interface to the head units is a NEC chip numbered 780053050. I found what I think is the chip from NEC's site:
uPD780053
8-Bit Single-Chip Microcontroller
http://www.necel.com/nesdis/image/U12013EJ3V2UD00.pdf

TheDosDog

I noticed in one of the Japanese accessory brochures that there is a JDM backup camera that mounts beside the CHSL in the decklid. Wouldn't the Nav screen be the logical display?

CactusGeorge

I don't have much on hand in the way of testing equipment, but I took some pictures of the circuit board and ohmed out some traces.

There are four NJM4556A-AM dual op amps. According to the ohm meter, LF-, RF-, LR- and RR- are independent traces. My guess is that each 4556A handles one channel and produces a differential signal between the outputs of the two op amps.

None of the "-" outputs appear to be connected to ground.

Pictures to follow.

CactusGeorge

For what it's worth--can't really make out much detail...

CactusGeorge

Focusing on the audio section...

mbkowns

Diggin it up from the grave but anyway check this out




Connect this to that magic port...



then connect this for aux-in




I wonder if it will work





It said it doesn't work for mazda 6 odd becuase the stereo in both is alike or same as far as I was concerned.


Diagram
http://www.discountcarstereo.com/mazpc-alp.pdf

eXentric

I was able to obtain more information on the P.I.E. Alpine Module. The tech support guy for P.I.E. was actually very informative.

According to him, the module will work just fine in the RX8 using the exact port we have been looking at all this time. Apparently, you can issue the following commands through this port:

Prev. Track
Next Track
Prev. Disc
Next Disc
Shuffle (Random) On / Off

The way you get the factory head unit to switch to the external cd changer is to hit the 'CD' button twice!

I think he mentioned other commands, but I don't recall them.

I asked him about using the Alpine analog RCA cable and he said it isn't possible. Apparently, their module just acts as a translater between the stock head unit and the Alpine CD changer. If no changer is attached, the requests sent from the head unit go unanswered and the head unit will not switch to that input. In addition, if you unplug the cable while its already playing, the head unit will go into an error mode waiting for for the changer to become available again. If it doesn't come back online, the head unit will return to FM.

At least that's what the guy told me. He did say that they had plans for an AUX module, but that they hadn't even started working on it yet. That module would have to 'appear' to the head unit to be an external CD changer.

So, at least there is some more information. This port can in fact be used, but we don't know how. I'm assuming that someone with a supported Alpine CD changer and a logic analyzer could purchase this PIE module and watch the communication that goes on between the head unit and the P.I.E. module. Someone could probably even record those signals and play them back and make a module to do this. But alas, that individual is not me

Regards

Yuhki

Maybe, this could be a nice solution for iPod user, because ALPINE annouced that they will release AI-NET iPod interface module within 2004 in U.S.( I am not sure in Japan )
( I am not iPod user though )

http://response.jp/issue/2004/0114/a...ges/60675.html

Japan8

You might want to try MP3Car site. They've cracked various systems command structure... like Clarion and Pioneer I think. Try searching there or looking through the audio section.

mbkowns

Still a great find etheir way : )

OverLOAD

Well.. presumably, this port would have the same bus connection as the rest of the system, since we've captured the bus messages from the CDC/MP3 CD/SCD using the tape port.

The only difference is that the messages we have from the tape module only enable the audio inputs from the tape module.

It might be a different message to enable to audio input source from the rear plug. Cn anyone with NAV confirm/deny that this is in fact the plug used with the NAV system?

A bit of information about the bus, for those who want to know. it's a 300 baud (yeah, really slow) bi-directional open drain type bus. It's signalling methodology is based on the differential in signal short time and most messages fall between 16 bits and 32 bits for the tape module. The message structure has a very basic type of header/encapsulation, and some messages have what appears to be a checksum, that I can't currently resolve.

However, this bus is pretty much across the whole head unit, and seems to have control to quite a lot of things.

Regards,

OverLOAD

bobclevenger

I have the nav system and the Bose. That socket (16-pin, located next to the antenna jack) is not used on my car.

I suspect that it MAY be used for the TV system for JDM cars. Can any of our Japanese members confirm or deny?

OK,now I'll go put my car back together.

jdaled

I found this yesterday while searching around again...

http://www.fosketts.net/miata/audiopins/index.html

It refers to the Miata systems in particular, but the information on the newer Miatas (2001/2002 onward) seems to describe the same system that is now used in the 8... and the 6, 3...

I know this information is already out there in a couple places, but I thought this was a nicely organized collection of relevant information, all in one place.

eXentric

Well, that is a good wealth of information on that page. That guy's done his homework. Thanks for including it. I also noticed that he mentioned a possible Sirrius Satellite option for new RX8's. It would be quite interesting to see what that device does, and I agree that this port would make sense for that application.

OverLOAD, thanks for sharing some of the protocol information. Assuming our diagrams are correct and pins K and L are data - and data + respectively, is there any way you would be willing to attempt a shot at messing with this port? You mentioned that it would be easier to obtain a connector that works with this port and I agree. Could this port be the way to complete the custom AUX in project?

I would be willing to send some cash up frot or even consider purchasing and sending you the P.I.E. module if you would be willing to attempt to hack the bus on this port. I'm sure a few others would help me come up with a bit of petty cash if it means we get our module.

If OverLOAD isn't interested, and / or if there is anyone else in the Houston area with some electronics expertise, I'd really like to try and attack this port. I'm a software engineer and I have a tiny bit of microcontroller coding knowledge, but not really enough to make a whack at this.

I just feel that we're so close. OverLOAD already understands a good portion of the protocol the head unit speaks, and it's obvious that this port can be used for auxillary sound. It's also obvious that there is a data bus available on the this port. I just have to believe that we (OverLOAD) would already be 80% of the way though hacking this port. If he's interested, I think we should support his efforts at looking at this port as much as possible. If he isn't intersted, hopefully he'll be willing to share his knowledge of the protocol and someone else can step in.

Anyone reading this thread or the other desparately needs AUX in, and there has to be away to do it. Whether it's inside the head unit or out.

mbkowns

No one gave me credit for finding the PIE module... I think its time overload made a website for this aux-module and we could paypal donations to boost the project along. Overload money is money get the ball rolling

eXentric

What kind of credit would you like mbkowns? In OverLOADs thread you made a comment with a similar tone.

Are we all not attempting to acheive the same goal? Many of us have spent hours of our personal time pouring over technical documents or removing our head units and attempting custom wire jobs. OverLOAD has even gone so far as to attempt to make good headway at hacking the head unit communication protocol - a feat not easily acheivable by probably 98% of the users on this board.

Even so, I have yet to hear him or anyone else in the history of thread complain that they haven't gotten credit where credit is due. We're all working toward the same goal and the satisfaction we will all receive will be a working AUX-IN solution when it is finally available. And virtually every person that has posted to these two threads will have contributed in some way to making that happen. Shouldn't that be satisfaction enough?

eXe

mbkowns

all i was saying is no one said thanks for the link ... jesus ....

Omicron

Thanks for finding the link to the info on the PIE module, mbkowns, it's a nice contribution to this project! :D

OverLOAD

The use of the external port is something that I'm definately interested in figuring out.

It won't be as simple as just plugging in the aux-module to the port though, I believe.

I think that the tape module specifically tells the HU to turn on the audio input from the lower module bay, like the CDC and mp3 cd tell it to enable to upper audio plug.

In order to figure out how to make it turn on the external audio port (and yes, it should be possible, even easy to make the aux-module plug in here instead). We'd probably just reverse engineer the input from the alpine CDC over the external bus plug to see what message it uses to turn it on.

Looks very do-able. I believe that the same internal bus line connects back to this location too. I'll consult the wiring diagrams to see what the pinout is and list it back here.

Regards,

OVerLOAD

OverLOAD

p.s. thought I'd attach this. Even though this doesn't seem to be the same connector, it's probably physically possible to plug it in the same place..

eXentric

That's what I figured, but keep this in mind:

From what I've heard, it doesn't look like there's any way for the external module to get the HU to select a particular input. The PIE technical contact told me that their module is strictly on a reply basis. In other words, when you press the CD button twice, the HU sends a command over the bus and something on the external port must reply with a specific response. Otherwise the head unit just ignores the double CD tap.

I'm pretty sure this is exactly the way the internal cassette works, so I probably just misread what you said. But, the command will obviously be different because we are talking about a different port and as I understand it (correct me if I'm wrong) the buss is a common buss no matter where you tap into it (CD, Cassette, back port, etc).

OverLOAD can easily obtain the PIE module, but does anyone have an Alpine 6-disc changer we could lend to OverLOADto hack the protocol? The mentioned ones are the CHM-S630 or CHA-S634 but it says almost any one will work.

Or do you even need that OverLOAD?

OverLOAD

eXentric,

From the messages I've hacked already, I can force the HU to turn on tape mode.

I can simulate HU event mesasges, as well as replies from any device. The timing on some devices is slightly different, but I believe that its from spec variances rather than from origin of the message.

I can send a message in normal MP3CD/CD/tape or CDC mode to force it to change to any other mode without pushing a button. It's relatively trivial, just send the origin message that the HU expects to see from the device on it's start message.

I don't want the PIE module yet... but it might make for an interesting find if someone can get the JDM tv tuner.

Regards,

OverLOAD