M-Bus CD changer adapter for car pc integration - Page 20

slarty · 10-25-2005, 02:12 PM

Sorry my only experience of MOST is from Volvo's Service application VADIS

They state that there is a maintenance packet sent around the system that checks on the system. I was concerned that there may be components in the system like the seat belts which are connected to the system and maybe the airbags that might be connected. I know that you recieve messages from the MOST BUS on an LCD that reports seat belt information so I presume that airbags may be on the same system. This being the case? If the adapter caused issues under testing would simply disconnecting it and restarting the car cause any issues to go away?

I see you say that it only happens during the time that the device is connected so that should mean that my worries above are for no reason. However will the MOST BUS record the connection of that device.

I'd like to see a PC adapter for MOST and would be willing to pay? how much would you say that a retail version would go for?

Thank you for your response and please excuse my delayed response and lack of knowledge on the MOST BUS. I am very interested in it's design and functionality.

Quote: Originally Posted by palta

Hello,
If the hardware you use is ok and the software you use doesnot behave too bad (like sending too much messages) the other component will work ok. If your hardware is not ok it is possible to influence the other components because it breaks the ring. There should be no critical systems on the bust (like ABS) only multimedia components. I'm not sure what you mean with maintenance system. The MOST master will check the bus if it gets desturbed to check where the ring broke but if you added a new component it should just use it.

In the MOST function catalog there are functions available that give you the data of the manufacturer of a device (but that you have to implement yourself ofcourse). So they could record the connection of other devices. MOST is designed to be a standard so you should be able to connect other devices. I do not think you can void the warrenty of your vehicle by connecting something to your audio system (that is illegal). Futhermore you cannot break devices by connecting something in the optical ring only desturb it during the time the device is connected.

With respect to the ipod interface you can find the information here:
http://www.oasis.de/files/Newsletter...r_V_I-2005.pdf
As you can read in the newsletter the reference design is free of royalties but I do not think Oasis would like single users to contact them. Futhermore you still need the components I mentioned in an earlier post.
Oasis also has MOST PC-cards but I do not really remember the price (I think it is more than 500 Euro).

Patrick

palta · 10-30-2005, 09:35 AM

Quote: Originally Posted by slarty

Sorry my only experience of MOST is from Volvo's Service application VADIS

They state that there is a maintenance packet sent around the system that checks on the system. I was concerned that there may be components in the system like the seat belts which are connected to the system and maybe the airbags that might be connected. I know that you recieve messages from the MOST BUS on an LCD that reports seat belt information so I presume that airbags may be on the same system. This being the case? If the adapter caused issues under testing would simply disconnecting it and restarting the car cause any issues to go away?

I see you say that it only happens during the time that the device is connected so that should mean that my worries above are for no reason. However will the MOST BUS record the connection of that device.

I'd like to see a PC adapter for MOST and would be willing to pay? how much would you say that a retail version would go for?

Thank you for your response and please excuse my delayed response and lack of knowledge on the MOST BUS. I am very interested in it's design and functionality.

I have experience with the MOST bus but do not know exactly how Volvo uses it.

With respect to the safety belts, airbags and other critical devices; MOST is not developed to control these. I think they are only connected to a device in the MOST ring to be able to display messages.
Problems you cause by experimenting with the MOST bus should go away when you disconnect the device. The MOST bus doesnot record anything. It possible to create a device that can record these events and store them in some kind of memory but I do not think this will be the case (what will the company gain with this effort?)

There are some interfaces used for development of MOST devices (.e.g. http://www.oasis.de/eng/content/view/181/228/ ) but I do not know what they cost (it is certainly more than 200 Euro because that costed a driver update if I remember correctly) and if they will sell these things to private persons.
I'm not sure if there is a big market for a MOST interface but if somebody wants to build one I can help.

Patrick

slarty · 11-01-2005, 04:30 PM

This sounds just how it works with the Volvo. I believe that Volvo does have a recording device for something as they state very clearly that any issues with the car that are recorded could be given to authorities if they should request them ... in so many words.. Unless this is another part of the system again separate from the MOST BUS. I do not know I am makeing assumptions from watching vehicle operations, Reading VADIS and the car manual.

I will follow up your link I'm desparate for a module I can plug in and get the PC connected... but I'll make do with FM for the time being.

Thanks for the help Palta! appreciated

Quote: Originally Posted by palta

I have experience with the MOST bus but do not know exactly how Volvo uses it.

With respect to the safety belts, airbags and other critical devices; MOST is not developed to control these. I think they are only connected to a device in the MOST ring to be able to display messages.
Problems you cause by experimenting with the MOST bus should go away when you disconnect the device. The MOST bus doesnot record anything. It possible to create a device that can record these events and store them in some kind of memory but I do not think this will be the case (what will the company gain with this effort?)

There are some interfaces used for development of MOST devices (.e.g. http://www.oasis.de/eng/content/view/181/228/ ) but I do not know what they cost (it is certainly more than 200 Euro because that costed a driver update if I remember correctly) and if they will sell these things to private persons.
I'm not sure if there is a big market for a MOST interface but if somebody wants to build one I can help.

Patrick

EseKuent · 11-29-2005, 06:52 PM

I've been reading this post for a while and hope that someone here may be able to help me.

After reading Joerg Hohensohn webpage (copy at: http://www.jevinskie.org/genmay/mbus/ ) I made my own MBUS dongle in order to talk with my alpine headunit (CDM-7835RM)... I've managed to program the atmel with PonyProg and now I'm trying to get it working.

Everything seems to be Ok (checked the circuit till I'm sick)... But when I connect it to the headunit and the PC there's no way to get it working. I'm trying to monitorize or emulate with Joerg's "MBUS monitor" but there's no way. I don't get anything there.

I'm waiting for an oscilloscope as by now there's no way to know if there are signals from/to MBUS or from/to RS232 (well, RS232 clearly seems to be "dead").

Is there anybody that managed to get Joerg's dongle working? Am I missing something? JBors: Did you try this circuit?

JBORS, I'm interested in your piece of hardware but I prefer it to be RS232 rather than USB... And I live in spain... So I end up paying more on shipping and toll's than for the adapter.

jbors · 11-29-2005, 10:07 PM

I did not try that circuit but pretty sure it works.
You can grab schematics for my adapter somewhere in this thread and it works for sure

If you just want the adapter and no wires then it will be pretty small package. I think will be $8 and adapter itself $40.
BTW: I can send you the pic program as well.

pemula · 12-26-2005, 07:42 PM

Please forgive my english...
I may be not following or my english so poor, but when I browse and search about IP-bus all the threads are talking about controlling and displaying carputer's audio application by HU.
I want it in reversed way... How to control cd changer by our carputer? say it via USB or RS-232 to IP-bus converter? Anybody has tried it?
Thanks in advance...

jbors · 12-26-2005, 10:25 PM

It is possible. The set of commands can be sent to cd changer and you can get audio data back. Why do you need it though ?

pemula · 12-27-2005, 12:24 AM

The idea is to make carputer the center of command in the car...
Yes, I agree that a pc can do more than a cdchanger in such a way of microprocessing, but as a matter of fact, cdchanger holds more cd(s) than a pc...
So, I want my carputer could control cdchanger (since digital auido still at the top for me...), and doing all other things the computer shold do...
and even taking control of car's engine, voice command, navigation, etc...

Am I only dreaming ?

SnyperBob · 12-27-2005, 01:25 AM

Seems to me that creating a hardware/software interface to make your carputer control your CD player would be a lot harder and more expensive that just ripping your CDs to MP3 and playing them via your carputer.

You mentioned that the CD player holds more CDs than the computer CD drive, but wouldn't it still be easier to rip your music to your harddrive. No worry about scratched discs, etc...

I suppose one advantage to keeping the stock CD player in the car is for when your carputer isn't in the car. That's about the only reason I can think of. Based on the work that jbors has already done in reverse engineering the stereos, I'm sure it wouldn't be that much more work to emulate the head unit buttons and have the carputer send those commands.

hmmmm

jbors · 12-27-2005, 01:26 AM

No it is possible. I would take digital output from PC and install DVD-ROM which is ~8 CDs. Anyway good luck in this venture...

t0ffluss · 12-30-2005, 07:06 PM

hmm.. very interesting work your doing Jbors, Iwe read some on the IP-Bus request on this thread and must say Im quite interested

one thing.. I just bought a Pioneer Headunit from a user on these forums, (DEH-P7500MP) the unit came with an IP-Bus --> Rca cable, but there is no way of making the player enter "AUX" mode... (pressing "src" only cycles "Tuner" and "CD player")

any ideas?

best regards
Richard
Norway

ps: happy new year!

Enforcer · 12-30-2005, 08:27 PM

Quote: Originally Posted by t0ffluss

hmm.. very interesting work your doing Jbors, Iwe read some on the IP-Bus request on this thread and must say Im quite interested

one thing.. I just bought a Pioneer Headunit from a user on these forums, (DEH-P7500MP) the unit came with an IP-Bus --> Rca cable, but there is no way of making the player enter "AUX" mode... (pressing "src" only cycles "Tuner" and "CD player")

any ideas?

best regards
Richard
Norway

ps: happy new year!

You need to enable the AUX mode.

IIRC with the unit in standby mode (ie off) hold the source button for a few seconds, the ubit will come on and be in a type of set up mode, use function to then go through the different options. One will be AUX on/off.

t0ffluss · 12-31-2005, 05:24 AM

Quote: Originally Posted by Enforcer

You need to enable the AUX mode.

IIRC with the unit in standby mode (ie off) hold the source button for a few seconds, the ubit will come on and be in a type of set up mode, use function to then go through the different options. One will be AUX on/off.

thx!!!

Richard