bobclevenger

Certainly! I will put it up on my ftp site in the directory that anyone may login to. I will announce it here too.
I will e-mail you the upload login info.

bobclevenger

Tamas:
Oops, can't e-mail you. Check your PM's instead.

eXentric

This is excellent news. Please let us know as soon as it's available.

Thank you everyone who has and continues to contribute to this effort.

RX-8-Tobi

Hey Tamas,

good news.
But 6MB is ******* huge! Well, give i to Bobby and I will download it. Knowing a bit about digital imaging, I am sure I can make it SMALLER and after that I can upload it to my homepage if you give me the "license". :p

rgds
Tobi

Tamas

iTrader: (1)

I don't have any sort of license
I got the whole service manual from another forum member in PDF format. I don't really have the right to distribute it any further unless I ask him first - but I suppose for the sake of this hacking attempt, uploading the wiring chapter is OK
I will try to do the upload now.

Rx-Appreci-8

Tobi / Tamas / Bob / eXentric

I sure would like to download that file as well. 6MB isn't a problem for me to download but I don't have a way to post it.

bobclevenger

It's already posted! info is in this thread.

And 6MB is tiny compared to what I usually serve up/down on this server --- noooo problem!

eXentric

I've read the PDF almost front to back. Unfortunately, I don't see anything new that would help us. Did anyone catch anything I missed?

I'm still trying to decide if I have enough courage to send voltage through the 'system mute' pin or if I'm going to woose out and go with the cassette module hack...

Rx-Appreci-8

The audio schematics starting on page 84 cleared up a few things for me such as how the NAV intercepts the front left speaker only and how the steering wheel's audio control buttons hook to the audio head unit at pins 1P & 1N with a variable resistance depending on which button is depressed. Looks like I can get the audio mute function working with my cell phone hands free adapter using just a relay and resistor at 1P & 1N to simulate the mute button on the steering column.

The schematic also shows how vehicle power and ACC is supplied to the radio unit at pins 1B and 1R of the big connector.

WHY CAN'T WE FEED AUX SIGNALS FROM OUR ACCESSORIES DIRECTLY INTO THE MAIN AMP???

The schematic shows audio wiring w/wo NAV option and w/wo a main power amp BOSE option. For those with the main amp option, shouldn't the differential interface between radio head and main amp have signal amplitudes in the neighborhood of a LINE level signal when volume is turned up? If so, why can't we insert a toggle switch or relay between the radio head and the main amp so the main amp gets selective input from either the radio head or from an AUX source. I think it would be worthwhile getting in the trunk with an oscilloscope and measuring at least one of the four differential audio signals between the radio and the main amp to see how closely they match a normal audio output from an MP3 player or SAT Radio, etc. We still have the differential vs. single ended issue and we may need to add some amplification or attenuation and perhaps even impedance matching. On the other hand we might be able to connect the MP3 output directly to the + input to the main amp and ground the - input signal to see if we get acceptable audio. If the relative amplitudes are way off, we could tailor a custom preamp to feed AUX IN from our MP3 players directly into the main amp through a selective switch. If this would work at lease we would not have to get into all the computer handshaking issues we discussed earlier or the "run a dummy tape in the cassette player" for the cassette hack option.

I won't be able to tear into my car until after Christmas. At that time I could certainly get in the trunk with a portable oscilloscope and measure the signal level between radio head output and main amp input to see how much gain or attenuation is needed (unless Bob or someone else does it sooner).

Page 89 shows that the main amp is located in the trunk between the two speakers. This looks like an ideal location for a quick test.

I'm optimistic that an AUX-IN solution exists without completely reverse engineering the cassette or radio head (which still might be fun to do).

Brett

Tamas

iTrader: (1)

OK, all of you hackers... please have mercy on us with the base sound system (and no electrical engineering degree ) - we too need our AUX input to the base head unit that has no external amp...

bobclevenger

Speaking for myself only, I completely understand, and I think that a proper solution will end up putting the Aux In into the audio head unit, because that's where all the controls are. The question is just how do we do it? We're working on it!

RX-8-Tobi

pc8,

We all want a universal solution that also works for all guys w/o BOSE.

I also do not like that solution. :p

rgds
Tobi

Rx-Appreci-8

I agree. Never mind.

Although the Mazda wiring diagram ends at the large J3 connector and vehicle wiring to J3 is different depending on the base / BOSE / NAV option, it DOES clearly show what is necessary to remove the entire radio / cd / cassette / display from the vehicle so it can be powered / operated / tested on a workbench. That's a BIG plus to me.

It doesn't appear that the radio head hooks to another vehicle computer bus via J3 so the BUS+ / BUS- signal appearing on the other connector seems far less intimidating to me now.

In the mean time I ordered a "sacrificial" cassette player the other day for my own hacking purposes. It would be nice to know what's going on with that BUS+ / BUS- interface.

Maybe an OEM radio / cassette / CD player schematic will still turn up.

regards,
Brett

eXentric

I didn't catch that. Can you elaborate?

I did catch that, but I didn't find any resistance values listed, did you? I'm know this can easily be determined with an ohm meter though.

Technically, I think you can. Check out this thread where we tapped the signal comming from the head unit. I'm still running my subs this way as of today, but I'm considering playing around with a Hi/Low converter to see how bad it sounds in comparison. My problem is that I have to have the gain turned up all the way on my amp to get sufficient volume out of songs that aren't really 'boomy'. So, I would assume that if you tried an input selection switch here and tried to route sound into the amp, it would work. But I think you would have to use extremely low volume levels or you would overdrive the stock amp.

However, I don't like the post-head unit solution either. I think there needs to be a pre-head unit answer to this problem. I actually like the way my head unit fits and may not ever replace it (even if there is an aftermarket mount). So I would like to see the answer routed through the stock unit.

Now that is sweet. Do you think you'll actually figure out something on the display itself?


Agreed. And if you have the hardware / know-how, by all means, PLEASE check this out. My dream would be to have a chip that interaces to this connector and provides RCA jacks and a USB port. The RCA jacks are obvious, but when I plug that USB port into my computer it would show up as a HID device (triggered from the steering wheel controls) and another device that could be written to to put text on the display panel.

I actually think that would be possible through that cassette BUS, but it would require some serious engineering to do something like that. It's just a dream

KEEP THIS STUFF COMMING!!! I'm holding off on the cassette module for now. This is just TOO interesting.

eXe

Rx-Appreci-8

I see 4 cases depicted...
Case 1 (Base Radio only) pg 84-85
Pg 84-85 shows the Base Radio only option where 4 channels from the audio unit directly drive 4 speaker locations. Note: the left front speaker is driven directly from pins 1A/1C on audio unit.

Case 2 (Base Radio + NAV) pg 92-97
Pg 92 - 97 shows the base radio + NAV (NO BOSE) case where all 4 speaker channels except 1A/1C go directly to speakers (as in case 1) However, the left front channel signal from radio head pins 1A/1C now go to NAV unit pins 1P/1O (pg 96) then through NAV and out NAV pins 1N/1M to front left speaker. NAV takes over this speaker when the lady wants to talk.

Case 3 (Base Radio + MAIN Amp) pg 86-91
Pg 86-91 shows the base radio feeding 5 channels (4 plus center) to the MAIN AMPLIFIER. I assume 1A/1C is still the front / left channel and goes to main amp pins 1P/1N then to the front left speaker

Case 4 (Base radio + NAV + MAIN AMP) pg 98-107
Page 98 – 107 shows 4 of the 5 channels feeding the MAIN AMP except left front channel pins 1A/1C go to NAV unit pins 1G/1E then out of the NAV unit on pins 1K/1I to the main amp 1P/1N

I had not seen that thread. Thanks! Good work you two. I'll catch up eventually

That makes sense to me if you don't connect differentially and haven't increased the gain by a factor of two. I couldn't tell exactly from the thread you gave me, but did you connect a single ended source to the main amp's input+ and ground the input- ? If so you are connecting at one half the normal amplitude that it sees if the SAME amplitude signal were to come in differentially with opposite phases.

regards,
Brett

eXentric

Rx-Appreci-8,

I sent you a PM with a couple of questions. I'm not sending signal into my stock amp, but rather I tapped into it parallel to send it to my subwoofer amp.

Anyway, if you can help me in my PM, I'll publish the results in the other thread (I don't want it to clutter up this one).

Thanks!

sixspeed

How's this going guys? Just wondered if any of you had managed to find out any more..

Mostly after a way of hooking in a hands-free unit at the moment, but plugging my Zen MP3 player in would be a bonus!


-andy-

eXentric

I haven't made any progress myself. I'm kind of hoping someone with a little more electronics knowledge will step up to the plate here. I'm just a little scared to start putting voltage on pins.

Also, you might be interested in this thread. If the guys really do pull it off, it should be sweet.

cauf

hello,
In belgium whe are following this topic with great interest ebcause there are many mazda 6 here.
I think you better work with the interior connector between the tape deck and the main console.
The conn is easy to make from dubbel sided circuit board.
( with a saw and dremel )
The main advantage is the fact ( I think !! ) that there is no BUS communication between the tape deck and the main unit and the
selection should be a simpel DC level ( 5 or 12V ) signal.
Hacking in the BUS communication on the other connectors will be extremely difficult.
Has anyone already measured the signals on this conn because I dont have a tape deck.
It should be no more than audio out L and R ,12V,gnd,mute, dashlight and selection.

Greetings
( sorry for my english )

Icanrel-8

Wait, wait!-- I saw this one.. um, you just open up the back of Commander Data's head, where the blinky lights are, and then use the carbide node isolater dealy to reset the....

:D :D Nah, I'm sorry guys, just funnin' with you. It is very cool that you are sorting this kind of thing out for our benefit. I'm a bear of very little brain that tried reading this thread, and my head almost exploded, and I just got silly. No offense intended.

Rx-Appreci-8

LOL I know what you mean Icanrel-8! As far as jargon goes that particular discussion got worse too, so we took it off-line to avoid putting other forum members to sleep.

But I think you might actually be onto something with your "carbide node isolater" concept!

Icanrel-8

Now I'm really sorry. Just because it was over my head, you all felt run off.

I think it is cool that you were figuring out the vehicle's flux capacitor or whatever, because the dealer is never gonna share that kind of hacking if they even knew how.

And I may not want to do whatever it is you're discussing (but I could any time, no really!), but this is what forum is all about. This isn't any different than posting how you got the Mazdaspeed fender flares on or coming up with a timing change that eliminates flooding. Just in a different language. I just felt like Barney Fife: Gee, Andy, I love that kinda talk. My father-in-law is the inventor of the Node Failure Restoration Tool. I have no eye-dee what the heck it does, but you gotta admire the guy.

Sorry for tripping into your thread and spilling beer on your algorithms 'n stuff. Cheers!

bobclevenger

I for one would like to see the ongoing discussion on this matter. I understand some of it and am willing to help with the experimentation. I think that those who are bored by this tech talk will just stop reading this thread. YMMV.

GiN

Good morning all -

Great thread! Please allow me to contribute 2 whole cents of information regarding a/v hacking:

"signal ground" is a device-generated ground or 0-volt (~1mV) commonly used as a "clean" reference voltage for shielding or "grounding". Low-voltage reference of this type prevents chance of interference as opposed to hard-grounding to the chassis.

The connectors some of you seek are manufactured by AMP corporation of Japan. They make the connectors found in the majority of automobile wiring systems. Sourcing part numbers may be a tedious if not impossible task unless it is printed on the connector. Thousands of variations of these multi-pin connectors exist, and many with exclusive "secret" identification numbers. To start, one would have to request a catalog from AMP or somehow get through to customer service - which may also be impossible unless you are a manufacturer representative.

Good luck! I'm trying to get a hold of complete vehicle schematics myself - if any information pops up you'll all be the first to know.

cauf

Hallo,
This is what I found out about the internal ,male, connector between tape and radio.
I assume that the selection is done by pin4 and/or pin 11.
I've put (by resistor 1k) 12V on them but no reaction.
If anyone has more info please put it on this thread.