you misunderstood what I was suggesting -- instead of asking for someone to meet him so he can test out his project, I'm suggesting that he buys a STOCK c5 radio, set it up on his bench, and test it that way.
I'm not suggesting he replace the stock headunit.

 

yes, we're all very familiar with theftlock here, trust me :-)
It will ask you for a 4 digit code to be typed in. just make sure you buy a radio and have the 4 digit code. I'm going from memory, but I believe there was a way to defeat the theftlock, there are TONS of threads on it... anyway, just a suggestion.-- seems like it would be much easier to have a radio set up as a test bench in your workspace than meeting with someone every time you want to test it out.

Also, you may not be aware of this, but in the C5, ALL cars with the bose system had a cable plugged into the back of the radio, that terminated in a female end in the passenger footwell, under a panel that literally snaps right out (it's designed to pull out, with a lever on it). If you have a CD changer, a cable plugs in there, under the passenger footwell access panel, and runs to the back of the car. Back in the day when adapters similar to the one you're making were common, we plugged in there. If you had a CD changer, most adapters had a y connector to keep your CD changer working. Just a suggestion, would be neater to plug in there as opposed to in the back. And likely a little easier to get to. AND, you'll have a system that works with cars that have changers and do not have changers.

 

Agreed. I have seen cars with an Aux cable run from the trunk to the arm rest with a mount.

Me being me.... if I were THAT intent on keeping the factory head unit, I'd add the Aux-in. When I did the BT adapter it was the cost effective choice at $90 for a car I thought I would be selling at the time. Otherwise, a tasteful head unit replacement solves all of these issues in one shot.

 

@korak1111
You are absolutely correct on this, I am (die hard) in the keep it original bucket. But not necessarily as it came from factory. I have integrated URPAS (the parking sensors) from '00 and up on '96 - '99 cars (not the Chinese generic one, I mean OEM GM equipment, retaining full functionality), massage seats (only '99 had them, can be installed in other years), various features like "mirror to curb in reverse", "honk on lock". One of the most ambitious (before the 1K Changer) is adapting the reverse camera with '99+ OEM rear view mirror (the one with the display). But why stop to just reverse, I added blind spot monitoring (camera based tied into the turn signal) plus GPS integration (compass) and splash screen on startup. All GM components and home made control module, retaining the auto-dimming (off course).

And correct, this is is my "life project", I am researching this for ~15 years, and in the last 3 years was my spare time project (by that I mean all vacations, weekends, evenings, often trading a lot of sleep for it).,
In November 2022 I had my first "break thru" after years and years or trying, I finally had the first successful communication with the radio on the E&C bus. I don't do drugs, never did, nor will ever do, but probably that "CD changer door open" message was more than any substance can ever do to you. Since then the discoveries have exponentially increased until in less than 1 year I had fully figured out the E&C protocol. The last 1+ years I spent perfecting the hardware (smaller, automotive grade reliability) and the firmware (testing and testing and testing some more).
I mentioned, the 1K Changer is plug and play, no wires to be splices, no programming needed, no compromise of any kind, exact functionality as GM intended, but significantly enhanced.
I take it badly when I see products that are kind of misleading, and are essentially a primitive hack. I have fully replicated a CD Changer, every feature, every functionality, and was hard, hard work.
The Chinese $100 radio in 3 years will be obsolete, slow (compared with the times) and look totally out of place, I am looking for the timeless solution.

 

I am somewhat aware of some cable in the passenger area, I learned form reading on this forum (thanks to the people on this forum for that!).
This is the reason I mentioned the C5 I am looking should be pre-equipped with the CD Changer because:
a) Is easy to access the CD Changer cable, no need to pry/unscrew anything, I do not feel comfortable doing it on not my car.
b) Is tested already that the radio works with the OEM CD changer
c) The 1K Changer has exactly the same connector as the CD Changer, I am not sure what kind of connector is in this intermediary location, most likely not the same.
d) I really need to know it works in a real car anyways. During the development, a "bench car" was fine, but eventually all validations end with the actual car.

The original VIN is not required technically, the GM procedure state that the "VIN Re-learn" procedure cannot be done w/o a proof of legal purchase of the radio (bill of sale) and the VIN of the donor vehicle.
With the TechII you can read the VIN stored in the radio and they do that to match it with the paperwork. The only technical thing needed is to clear the old VIN from EEPROM. I do have access to a scanner that can do this, so I can do it, in fact this is how I got my bench "car" environment set up. Is just that I don't know what module replies the VIN in the C5 (I need that too) and also I need to figure out the wiring diagram and such. I only have Cadillac stuff, that's my world.
As far as I know (and obviously I don't know much in this regards), you must somehow provide the VIN to the radio, either I make a module that does that, or I use the OEM module (the easiest way).
Oh, another thing, some of radios (all '98+ in Cadillac), will not run for more than 1 min w/o OBDII connection, they communicate with some other modules for various reasons (like the time, or the current driver profile selected), and if there is no data communication will time out after 1 min. You keep having to restart it, this is another thing I am not knowledgeable of. I don't know what other challenges the C5 radio will give me other than the VIN. Probably the module the radio get the VIN also is the one providing the other communication, at least that's the case for the Cadillac radios (either IPC or DIM), but is another unknown for me.


Is it possible that the C5 has a different Theftlock implementation, like the old fashion 3 or 4 digit code, which was common in the '90's on a lot of OEM (usually imports) and some of the (more expensive) aftermarket units?
Or, is the same implementation as in Cadillac, but perhaps the C5 Radio has the option to key in the code that erases the VIN, instead of doing it with the TechII? The Cadillac radios so not have the option to punch in a code, it must be OBDII instruction. And is odd, because Cadilacs do have full On Board Diagnosis (at least '96-'98('99, '02)), you have the full functionality of a OBDII scanner including resetting codes, overrides, test inputs/outputs and such, but not the security special functionality.

 

I can send you a pic of the plug in the passenger foot well.. when I say the access panel is meant to take out, it is-- no screws, no friction bolts, it's a lever, you pull it, the panel unlocks, and you pull the panel off. The cable is right there. only thing to take out is the floormat.

I only mention this because if you are making a completely universal solution, you may want to position it there. EVERYONE with a bose radio has that connector, but not everyone has a cd changer. or the cable going to the back of the car from the passenger footwell.

 

That will be much appreciated.
The trunk location is somewhat inconvenient because for AUX and Microphone I need to bring a cable from the trunk to the driver area and is a small module with the AUX jack and small hole for the microphone.
This cable is optional, you don't need it if you don't want to be bothered with this. You can use it for SD/USB replicating the OEM CD changer, and then the Bluetooth is well in range if you want to stream in.

In fact I designed 2 versions:
1K - SD/USB, Bluetooth streaming (including phone calls) and Aux input.
1k - SD/USB, Bluetooth streaming (only) and Aux input.

The difference is in the Bluetooth module, the 1k (base version) will not give the option to select the Bluetooth for phone calls, if you are connected to the 1k and you get a phone call while streaming, will only give the option to use the phone speaker or earpiece, once the call is over streaming is resumed. The reason is because there is no microphone.
The 1K does allows taking the calls via Bluetooth, but to do so you need the additional (optional) harness and module with the microphone.
I noticed that people seem to be very price sensitive (I don't blame them), and the optional harness is additional cost.
If I have the option to bring the 1K near the driver, I don't need the optional harness, I can incorporate the microphone inside, is significantly more cost effective, in fact I will just revise the PCB layout for that later.

The thing is I am working from the following perspective (and I will not budge):
1. Plug and play, anybody can "install" it, ages 7 and up.
2. Kind of continuation to 1, no wires/panels to be messed with.
3. 100% preserving original CD Changer functionality, but enhance it. Actually there is still the option to keep the original CD Changer by plugging the 1K into the CD Changer (daisy chain + a mode switch).

Come to think, some of the Cadillacs do have the CD changer in the Center Console or Glove Box, those are a good fit for this integrated option along with the C5.

 

Still looking for a local (to me) C5 Corvette owner willing to volunteer his/her car for "science".
I just finished the case for the 1K CD Changer replacement, and this is what I will be connecting to the car for testing:


First 1K unit completed

All I need to do is unplug the factory CD Changer and plug the 1K in place. You can see in the picture bellow the USB port, the Micro SD Card slot just next to the harness connector. In the top picture you see the port for the optional Aux Input and Microphone harness.

1K USB Port and SD Card Slot

The case has no functional purpose, other than preventing shorting the PCB, what really matters is what is inside, but hopefully this puts people at ease for testing,.
And yes, I noticed too, I put the Bluetooth symbol next to the SD Card/USB port instead of the MP3 logo. The next case will have them swapped.

So you can be the first to hear mp3 playing straight from the C5 sound system, assuming the 1K works with the C5, not just Cadillacs. But that's really what I am trying to validate and the reason for this thread.

 

What's local for you? Am in CT.

 

Hey Tusc,

Local for me is Toronto ON, or Palm Coast FL, but practically for most of the time (specifically now) is Toronto, as much as I rather be in FL.

 

I used to frequent both areas in my first marriage, but no more. I enjoyed Canada more than Florida but that is because we were tied down to the horse business.

 

well, it looks professional!!
curious, why does it matter which logo comes first, is it part of the standard, or personal preference?

 

Is just a personal preference based on what makes sense.
See bellow the Bluetooth logo is Micro SD card slot and a USB port?
Perhaps the area where the Micro SD card slot is too dark and is not showing well in the picture (second picture). I mean I see it, because I know what is there, but the casual observer will not.
So the reason to place the mp3 logo first (swapping place with the Bluetooth logo) is because the mp3 logo is also indicating where to get the mp3-s in (either in the microSD slot or USB port).
So the logo and logo placement has a double meaning, what is supports and where to put the mp3s in.

Hopefully that makes sense now.

PS. I already updated the CAD to swap the logos.
Also lesson learned, the MicroSD slot is too "micro". I mean the bevel I made around the slot is not large enough to fit the tip of an adult's finger to push the card in/out. I need to make some kind of a dimple like indentation in the center about the size of an adult finger's tip. Right now is difficult to push the card enough to release w/o using some kind of a sharp tool. If you have a laptop with a SD card slot, look at the design how the opening is shaped, that's pretty much what I need to replicate.

 

On the other note, I was able to locate a C5 in Alberta .
Obviously both Tusk and Korak are a lot closer to me than Alberta...

Still looking...maybe the car show season is about to start, I can roam along the shows to find one.

 

I am always willing to help folks. I guess I am only too far away if you need to be present for testing. But JMG2 is right down the street here as well.

 

What bluetooth revision and codecs will your unit use?

 

There are 2 versions:

1K
Manufacturer: Qualcom
Bluetooth version 4.0
HFP v1.6, A2DP v1.2 AVRCP v1.4

1k
Manufacturer: Multiple (under license from Qualcom)
Version 4.2
HFPV1.7, A2DP v1.2, AVRCP v1.5, AVCTP v1.2, AVDTP v1.2

I know 1k sound better (specs wise), but actually the Bluetooth module in the 1K is the one with streaming and phone call support (and is significantly more expensive), while 1k only supports streaming. Essentially this is the difference between 1K and 1k.

In more details, the 1K Bluetooth chip has both HSP and A2DP enabled while the 1k Bluetooth chip only has A2DP enabled.
In reality both chips have the HSP enabled, just that 1k has it only enabled for local use (via 1 analog input), i.e. I can still submit requests to control the track (next/previous), but I can't connect a microphone, is marked off in the handshake. All this mumbo-jumbo really means, when connected to the 1K both the streaming and the microphone (i.e. both way audio) is enabled, whereas on the 1k the microphone is disabled (only streaming one way audio). Controls (next/previous) work in both versions.

If you have a Bluetooth speaker, or a TV sound bar, 90% chances it used the same Bluetooth chip as the one in 1k. This chip is geared mostly for these kind of applications.
If you have a car with phone support or a hands free phone adapter, then is likely to use the same chip as the one in 1K.

Perhaps it makes sense if I mention that both chips are based on the CSR architecture (British IP), Qualcom owns the rights now, makes it own and also licenses to other manufacturers.

Regardless, both will support any device you may have (phone, tablet, laptop).

 

I think what your doing is incredible. I wish I could understand the data signals needed to do this. That being said. There have been devices that do this forever other than a sd card slot. I use a direct wired solution replacing the cd changer. Unfortunately my new phone doesnt have a 3.5 jack so I will be switching to bluetooth. Your bluetooth is outdated. You need to be at the level of a fiio bluetooth dac at this point. The sd card interface is too cumbersome without a display nowadays. Use your knowledge of the handshake protocol for the gm radios to make a modern bluetooth 5.0 and up interface with hd codecs and hands free calling with noise cancellation. That will be what is wanted and isnt offered already. qualcomm QCC514, QCC5181.
What is currently available https://www.discountcarstereo.com/pdf/c5_chart.pdf
These use bluetooth 4.2. you need to make a better device.

 

I need to explain, the actual Bluetooth module I am using is not very important. I was just listing the Bluetooth modules I have now.
Think of it like the tires on a car, or the RAM chip you install on your PC. I can install whichever I want/afford, w/o any changes to the car/PC, as long as I am keeping within the specs/limitations.

For example CSRA64215 is advertised as v5.0 (although it might be bull), so is QCC3005 (which is indeed v5.0) and are a direct fit for the 1K version (and is ~7% difference in price). For the 1k, the best module I can find is 4.2, but my God it is so much cheaper, and in terms of sound quality and connectivity/range, is absolutely identical with the much more expensive 1K modules.

QCC514 is more suitable for headphones (hence the ANC), true noise cancelation in open space (I would say the car is an open space from this perspective) is very difficult to achieve, and whatever they claim is mostly marketing, not science.
Really the main difference (wildly publicized) is how much more power efficient the 5.0 devices are, we are already under 10mA to begin with, so if is 10mA or 6mA (I just stated a number, not sure if is actually 6), is really not relevant in this application, the OEM CD changer is using 300+ mA (in standard operation), and goes into the Amps for when is shifting trays around. So we are talking of less than 1% and from the marketing point of view is blown into space. Sure, if we are talking of ear buds applications, yes I agree, 1mA is significant!

I will explain my philosophy, I am looking for a plug and play solution that can be accommodated by the car OEM equipment and harness. Also I do not want to lose any existing features, so just making a Bluetooth only device, that only will be "seen" by the radio as 1 "disk" and not being able to play up to 12 "disks" as originally supported is very easy (relatively speaking), but I consider it lost of functionality.
I an working with the HUGE constrains of the E&C protocol designed in the late '80, we had no mp3, or GB size SD cards or Bluetooth back then. I am really frustrated with the 2 digit limitation for the track numbers, but I do exploit (heavily) the lack of "awareness" of the track timer rolling over 99 min so I am essentially playing infinite loop "tracks" while in Bluetooth or Aux mode.
You are so right with the remark about controlling an SD card with the very limited display in the radio. I mean finding a certain "track" (within the 99, hopefully you at least remember the "disk" number) is not easy, sometimes too many choices are making it difficult, so maybe the 2 digits limitation is for a good cause.


Here is a fun picture, I bet nobody ever saw over 74:00 on this screen (74 min is the max duration of the standard CD, original specifications).

Beyond the limits of the CD. Get it? "disk" 12 minute 99:59, this is literally the end of time, but I went further...


Actually installing a microphone somewhere in the vehicle (which is what you need for voice calls and any rudimentary form of ANC), involves a extra harness, pulling panels, unscrewing stuff, that is not really plug and play. This is the main reason I have 2 models, 1K and 1k. The 1k (if don't care of Aux input) it plugs in the CD changer harness and gives mp3 and Bluetooth instantly. The 1K is the one that will require running a cable to bring the microphone in the driver's area, I do not see the regular person doing that, I mean you and I, enthusiasts with DIY skills will definitely prefer this "complication" for the voice calls, but we are not the average user.

Personally I would not ever install something in my car that somewhat compromises the original functionality, this is why I added microSD/USB support, it is what allows me to retain fully the OEM CD features, I am aware that most people will just use the Bluetooth to "Spotify" into the radio. Things like FM modulators (like those CD Changer they use to make), or FM modulator Bluetooth devices, or using some remote control (wired or not) to control the aftermarket device, just because you cannot integrate it with the radio directly, those are to me just like a cigarette lighter crock pot or lava lamp...
Weird enough, I am not actually against tape adapters or even better the Bluetooth tape adapter.

Regarding installing a an aftermarket head unit in the car...
Think like this, back in 1981 you spent $2000 to buy the absolute best tape player for your 1966 Mustang.
What would be today the value of this "investment"?

I do appreciate this conversation, is very constructive, it gives me great insides in what the people are expecting, and I really appreciate the diagram provided.
I hope I explained well what is my "philosophy" towards this project.


Still looking for that C5 in the Toronto area...

 

This reminds me so much of my Neuros and Neuros 2 back in the day when iPods had just come out.