CDC40 and DAB unit CAN BUS communication

[salakala]

Hello

I'm trying to use CDC40's DAB audio-in pins for AUX-in. I get a cheap DAB45 box from ebay. Everything is connected and working. But the problem is that we dont have DAB broadcasts here in finland and it seems that if DAB box dont have reception it dont send commands to head unit to activate DAB audio in signal. So no DAB reception -> CDC40 DAB audio pins inactive.

So now I would like to ask in anyone of you have or is able to get MS-CAN bus traces of head unit and DAB box communication.

I attached trace of messages that DAB box is sending to can bus.

Thanx in advance!

CAN-bus-traffic-from-DAB45.txt

[pecky]

Unfortunately I don't have a canbus analyser to do any traces otherwise I would have done it for you. Is that an Elrasoft one you are using?

Also the attachment for the traces didn't load in for some reason.

[domtorredo]

have looked at elrasoft can analyzer will be getting one soon but that in image looks something else
without reception not easy to analyze but you can still analyze other things like how info is passed to screen, steering wheel controls messages etc
with ehu and screen it will be much easier on bench

[salakala]

Pecky:
That's pity. Maybe one day.

I'm using peak-system PCAN-USB with Busmaster software in windows and also Microchip MCP2515 SPI CAN chip hooked to raspberrypi and SocketCAN in linux. There is also linux support for PCAN-USB.

I have get the basic idea how texts and menus are sent to GID over can bus. Mania's comments in that mp3car thread where great help.

I have done some programing test with socketCAN python bindings and I where able to bild custom menu and scroll on it with steering wheel controls. Next task is to figure out how menu entry selection works.

[pecky]

I barely have enough time to do anything as it is, why on earth have you shown me something like this

Time to get the credit card out

[Ian T]

I barely have enough time to do anything as it is, why on earth have you shown me something like this

Time to get the credit card out

I agree, I have a couple of spare Raspberry Pi and was wondering what to do with the next one... It makes a really nice low power controller at simplest, but relatively easily, a full function computer that would interface flawlessly with all the vehicle systems... diagnosis, BC functions, entertainment, whatever.

I REALLY don't have time these days, so I'll have to stick to watching other people do clever things for the moment.

Ian.

[domtorredo]

anyway its a good start
got arduino dev board but dont have time to start too bought house got loads to plaster pipeworks etc
but in plans is as astra doesnt have temp gauge it can be made sniffing can data and displayed on seperate screen aswell as boost voltage and things like that what we dont see but are transmited over can
in simpler words all data is transmitted over can even coding/programming what can be sniffed and used with low cost device but it takes time for checking them all and implenting in 3rd party code

[Ian T]

There is certainly a precedent there, when I used to own a Merc E Class, I came across a guy who had built up a simple interface using the Microchip CAN driver and a smal PIC, just to grab the steering wheel controls and use them to drive an aftermarket mobile phone kit.

Using the same setup for reading out coolant temperature is something I had considered, but at the same time thought it cheaper to just add an additional temperature sensor. Itwould be neat to be able to incorporate it into the IPC though.

Ian.

[domtorredo]

yep one more sensor and gauge is cheaper way but for fun and playing around some external screen with more info would be nice
its no where to fit new screen in ipc but it can be linked to ipc screen as its done by happylights or whatever they was but again in not confortable better to go with one more screen in right place (mot/safety)

[berrynice]

Hi,

Is there any follow-up of this topic? I may be able to help on this issue. I'm waiting for the reception of a CDC 40 for an Astra H for which I want to use the aux input. I'll try to find out if there's any firmware modification that may work out, provided that in the end i'm able to generate the correct checksum.