Emulate Blaupunkt Changer

mrblau · 07-14-2004, 07:13 AM

I am currently working on a program that will emulate a blaupunkt changer.
This will allow the carpc to listen to button presses from the head unit and display text on the head unit.

I have tapped in to the serial line between the HU and changer and have figured out what most of the messages being sent mean.

Has anyone on this forum ever tried doing this before (I found an ancient post from Pressslab but that was all)? I'd like to know if anyone is interested or has information from their attempts at a similar project.

freddym · 08-11-2004, 05:43 AM

I am also trying to emulate a CD changer in order to get the AUX-Input on my Blaupunkt DX-R4 working. I'd like to connect my PDA with MP3s to the AUX-Input, and actually don't need any input-possibilities via the front-end radio, but I only need to emulate the presence of the changer in order to be able to activate the AUX-Input.

It would be nice to know what you found out - perhaps you can drop me a mail.

4u2n · 08-12-2004, 03:58 PM

Quote: Originally Posted by mrblau

I am currently working on a program that will emulate a blaupunkt changer.
This will allow the carpc to listen to button presses from the head unit and display text on the head unit.

I have tapped in to the serial line between the HU and changer and have figured out what most of the messages being sent mean.

Has anyone on this forum ever tried doing this before (I found an ancient post from Pressslab but that was all)? I'd like to know if anyone is interested or has information from their attempts at a similar project.

If you make it work,, mail me

I have idea to make the joystik (blaupunkt) control the PC thru the blaupunkt's changer connection

mrblau · 08-29-2004, 09:31 AM

Quote: Originally Posted by freddym

I am also trying to emulate a CD changer in order to get the AUX-Input on my Blaupunkt DX-R4 working. I'd like to connect my PDA with MP3s to the AUX-Input, and actually don't need any input-possibilities via the front-end radio, but I only need to emulate the presence of the changer in order to be able to activate the AUX-Input.

It would be nice to know what you found out - perhaps you can drop me a mail.

Hey,

Your head unit doesn't have an aux in, so you are right, you need to emulate the changer. Check out the third product on this crutchfield page it is supposed to hook up in place of a changer, looks like is has a chip attached to emulate the changer. It's so cheap you might as well try it.

mrblau

mrblau · 08-29-2004, 09:36 AM

4u2n,

Do you program in visual basic.net at all?
I gave up working on this for a while when uni started again but I am going to be working on it again soon.

4u2n · 08-29-2004, 09:46 AM

Quote: Originally Posted by mrblau

Hey,

Your head unit doesn't have an aux in, so you are right, you need to emulate the changer. Check out the third product on this crutchfield page it is supposed to hook up in place of a changer, looks like is has a chip attached to emulate the changer. It's so cheap you might as well try it.

mrblau

witch one can work with Blaupunkt receivers ???

mrblau · 08-29-2004, 10:08 AM

Quote: Originally Posted by 4u2n

witch one can work with Blaupunkt receivers ???

4u2n,

I am not completely sure about aux in cables. I am not using an aux in cable. I have modified my cd changer cable so that it will plug into my laptop as well as the cd-changer. When I make some more progress on my project I will post here.

andylaurence · 10-04-2004, 08:11 AM

I'm definitely interested. I have the Blaupunkt Sat Nav (option on the Ford Fiesta), so having to keep the CD in the slot, I really need another solution to playiong my CDs/MP3s. I've done a large amount of Googling, but all I've found is that it uses a form of serial protocol to talk to the changer, and the audio comes in via line inputs. Has anyone actually reverse engineered the protocol? If so, implementing an MP3 player shouldn't be too hard. If not, there's a lot of work to be done. I may just buy myself an MP3 CD changer from Ford!

Post any info here though - we may be able to make something of it, especially if someone has the work originally posted a couple of years ago here.

Cheers,
Andy

mrblau · 10-19-2004, 03:27 AM

Hello,

I have done a bit more work on my project but am stuck again.
The bus is just a serial connection. The HU and changer talk using hex bytes.
My program can receive the messages from the HU when the stereo is turned on, and I can echo HU messages like the changer did, and respond to HU messages. But as soon as it is time for the changer (my program) to send a message the HU seems to stop working. The HU does not continue with the sequence I recorded between the HU and real changer. It still echos anthing I send it though.

Maybe this is to do with timing?
I am using VB.Net and the moment because it is all I own. It seems difficult to make my program spit out responses at the exact same timing as the real changer.

djmickyg · 10-19-2004, 03:41 AM

some one please work this out for a pioneer bus plug

andylaurence · 10-19-2004, 03:56 AM

Perhaps this would be a good application for a micro, such as a PIC to emulate. Timing is much easier on a PIC. Use the PIC to communicate with the HU, and relay via standard RS232 to the PC. On the plus side, it's a doddle to program a PIC, and the same PC software could be used for any changer by coding a new PIC to suit.

Cheers,
Andy

mrblau · 11-11-2004, 07:49 AM

I can program things like cobol, java and .net fine but where is a good place to start learning about pic and assembly?

andylaurence · 11-11-2004, 10:05 AM

PICs are stupendously easy to program. I bought a little book from Amazon for about £5 (do a search for PIC and it's the cheap PIC projects one - Maplin normally have it on the shelf too). You've got a couple of options really. You can learn PICBASIC, which is a version of BASIC written for the PIC series of chips. You'll need to buy a copy of the PICBASIC compiler for this though. Alternatively, assembler is more difficult (although still quite easy), but the compilers are available for free. You only need a cheap programmer, which you can buy for less than £20. Maplin had one on offer last month for £15 IIRC.

Cheers,
Andy

andylaurence · 12-17-2004, 07:25 AM

I've found some Blaupunkt links which may help:

Some protocol information
http://www.mictronics.de/?page=cdc_proto

A VW-based implementation, but allegedly compatible with Blaupunkt protocol:
http://www.k9spud.com/vwcdpic/devel.html

I've also got pinouts, and part numbers of Blaupunkt connectors.

Cheers,
Andy (going to get working on this now)

mrblau · 12-25-2004, 10:24 AM

Andy, were you able to make any sense of the asm code on mictronics?