[cstavaru]

I don't know how many people know that BMW offers an ACM module which among other stuff (like playing divx movies and pictures from an USB stick) contains a CAN bus port. You can connect this port to a car pc via a CAN to USB adapter. Cost of ACM module is about $500 in the US, and a Car-PC can be had for $300+. So the setup would be cheaper than a Procede

What you could do with this:

- Have the car pc run the piggyback software and use the CANbus to control the ECU.
- Have the car pc output to the iDrive screen in real-time engine parameters, selected maps, gauges, etc. (the ACM module also has video inputs)
- Have the car pc play alarm sounds (e.g. overboost ?) via the car speakers
- Never have to open the ECU compartment to install a tune
- Updating, etc. done very easily via USB stick, etc.
- Everything almost OEM, no messing with anything besides the car PC

[vgame64]

Very cool. Thanks for the information.

[nood1es]

wow, that'd be pimp.

[alextremo]

do you have a link to where this product can be purchased?

[cstavaru]

Originally Posted by alextremo

do you have a link to where this product can be purchased?

The ACM module can be purchased/installed at BMW dealers. I don't know if it's available in US though.

[scalbert]

Originally Posted by cstavaru

Have the car pc run the piggyback software and use the CANbus to control the ECU.

The PROcede (or this) does not control the DME over the CAN network. That actual control is still made with the raw analog signals. The CAN data is used as a reference; i.e. read only.

[cstavaru]

Originally Posted by scalbert

The PROcede (or this) does not control the DME over the CAN network. That actual control is still made with the raw analog signals. The CAN data is used as a reference; i.e. read only.

I understand, but the question is, can the ECU be controlled via CAN bus data ? I remember reading a post from Shiv where he sais that an upcoming Procede will use CANbus exclusively.

[scalbert]

Originally Posted by cstavaru

I understand, but the question is, can the ECU be controlled via CAN bus data ? I remember reading a post from Shiv where he sais that an upcoming Procede will use CANbus exclusively.

No, it cannot. The DME uses the analog I/O to control the engine first and foremost. It may also reference data from the CAN network al well. But the hardwired sensors are the means of primary engine control information.

You must have misinterpreted what Shiv stated as that is not the case.

[cstavaru]

Originally Posted by scalbert

No, it cannot. The DME uses the analog I/O to control the engine first and foremost. It may also reference data from the CAN network al well. But the hardwired sensors are the means of primary engine control information.

You must have misinterpreted what Shiv stated as that is not the case.

Even so, the project can still be done: a much simpler module intercepts the hardwired sensors, and sends the information to the car pc, which in turn responds with the altered parameters...

JB3 seems perfect for the job but using such a module kind of defeats the purpose of the whole thing.

[scalbert]

Originally Posted by cstavaru

Even so, the project can still be done: a much simpler module intercepts the hardwired sensors, and sends the information to the car pc, which in turn responds with the altered parameters...

I can see it for visualization, but not acting as the piggy its self.

One thing to consider is boot time. A PC with minimal OS takes many second to boot. In that time the DME would be having a fit with the uncontrolled parameters and will throw several codes. You have to use an embedded controller that is essentially on once power is applied like what the PROcede and JB3 use.

Using a PC would require constant power to that PC (hopefully no reboots occur while driving ) or a MUX for all I/O.

[cstavaru]

Originally Posted by scalbert

I can see it for visualization, but not acting as the piggy its self.

One thing to consider is boot time. A PC with minimal OS takes many second to boot. In that time the DME would be having a fit with the uncontrolled parameters and will throw several codes. You have to use an embedded controller that is essentially on once power is applied like what the PROcede and JB3 use.

Using a PC would require constant power to that PC (hopefully no reboots occur while driving ) or a MUX for all I/O.

The boot time or random reboot is not really a problem. The interceptor module can just bypass the signals until it receives data signals from the computer so it just runs like stock if something happens.

[hun77777]

wait to see until what shiv or mike has to say about this

[Garissimo]

Originally Posted by cstavaru

The boot time or random reboot is not really a problem. The interceptor module can just bypass the signals until it receives data signals from the computer so it just runs like stock if something happens.

It's not just boot time. Even though the CPU in the control module might be up to snuff, it's highly doubtful that OS would be up to the task of real time control. The JB3 and Procede are running a real time control loop that needs to be deterministic down to the millisecond time frame (my guess) . Probably even faster than that for CPS offsetting. And they aren't burdened with multitasking. If you're running anything other than this hypothetical JB3 emulator app on your Car PC, the DME is not going to be happy the instant the OS takes a timeout to babysit the iDrive application.

I don't mean to dump cold water on your idea, but I don't see it being workable unless you optimize the Car PC to the point it does nothing but control the DME. And at that point, you're simply better off buying a piggyback that has the hardware and software tailor made for this application.

[cstavaru]

Originally Posted by Garissimo

It's not just boot time. Even though the CPU in the control module might be up to snuff, it's highly doubtful that OS would be up to the task of real time control. The JB3 and Procede are running a real time control loop that needs to be deterministic down to the millisecond time frame (my guess) . Probably even faster than that for CPS offsetting. And they aren't burdened with multitasking. If you're running anything other than this hypothetical JB3 emulator app on your Car PC, the DME is not going to be happy the instant the OS takes a timeout to babysit the iDrive application.

I don't mean to dump cold water on your idea, but I don't see it being workable unless you optimize the Car PC to the point it does nothing but control the DME. And at that point, you're simply better off buying a piggyback that has the hardware and software tailor made for this application.

This is a correct point of view.

The JB3 uses a Microchip PIC microcontroller running at ~10MHz or so. A nice decent Car PC has a dual-core or hyper-threaded Atom running at 1.6GHz and it is an X86 CISC processor, so it can execute an immense number of instructions per second. There are real-time extensions specifically made for Windows XP but I doubt they would be necessary for outputting a signal a few tens of times per second. However, the piggyback makers may know more about the resolution at which the signals are computed.

However, this project is not something I would like to build. This does not mean I will not pursue parts of this project that are in my field of knowledge (see my gauge thread...)

[alextremo]

Originally Posted by cstavaru

The ACM module can be purchased/installed at BMW dealers. I don't know if it's available in US though.

Do you have a p/n that can be looked up online?

[cstavaru]

Originally Posted by alextremo

Do you have a p/n that can be looked up online?

Yes:

Part number for the ACM module for old iDrive:

65500441372 (there was an old one with PN 65500418002)

Part number for the ACM module for new iDrive:

65502157356

[Mike@N54Tuning.com]

There is no way to alter the tuning without physically intercepting the sensors. And since you're in there anyway might as well read the sensors manually for the best resolution and response time. The JB3 samples the analogs around 200hz and could go 2-5x that if needed.

Mike

[scalbert]

Originally Posted by Mike@N54Tuning.com

And since you're in there anyway might as well read the sensors manually for the best resolution and response time.

Be careful on wording. Resolution could be interpreted as A/D which I beleive the JB3 is 10 bit which is hardly the best. Try 24 bit A/D if you want great resolution (better than what the sensors analog resolution).

[Mike@N54Tuning.com]

Originally Posted by scalbert

Be careful on wording. Resolution could be interpreted as A/D which I beleive the JB3 is 10 bit which is hardly the best. Try 24 bit A/D if you want great resolution (better than what the sensors analog resolution).

Such a stick in the mud. LOL Yes the JB3 and PROcede have "only" 10 bit AtoD. But you know I meant sample rate.

Mike

[scalbert]

Originally Posted by Mike@N54Tuning.com

Such a stick in the mud.

[IlChengis]

Interesting. Assuming you'd intercept the sensors and still see a benefit in having a CarPC run the show, you could bypass the boot-time/speed/stability issues by running some flavor of BSD with heavily slimmed kernel on SSD... now that would be a sweet setup, but the cost of SSD would significantly raise the price...

I am not sure about the tuning aspect of a project like this, but the multimedia/iDrive benefits are worth the efforts IMO. I would love to customize the iDrive and would be willing to invest in the above hardware if I'd be able to:

• Visualize my own sensors for engine monitoring purposes
• Watch DVDs while driving
• Do the CD-MP3 encoding with my own format preferences and choose target for saving and playback
• Add my own codecs so I can watch DiVX/XViD-encoded movies (5-7 movied would fit on a Data DVD)
• Offer an alternate NAV option that uses the Google Maps API and updates points of interest/local businesses etc using your phone (see below)
• Android integration(!)... the NexusOne is an amazing little unit and will soon get a car dock. iDrive integration/updates via 3G would rock.
• Add Bluetooth if your car doesn't have it
• ...much more

All of the above should have an iDrive feel and be offered as additional menu options.

I've been thinking about this for a while, as I said in another thread... I'd love to have the time to tinker with this and see how it all works to gauge feasibility.

Thoughts? Thank you for the info cstavaru, this module seems worth looking into!

-Walter

[scalbert]

Originally Posted by Treppiede

Interesting. Assuming you'd intercept the sensors and still see a benefit in having a CarPC run the show, you could bypass the boot-time/speed/stability issues by running some flavor of BSD with heavily slimmed kernel on SSD... now that would be a sweet setup, but the cost of SSD would significantly raise the price...

I am not sure about the tuning aspect of a project like this, but the multimedia/iDrive benefits are worth the efforts IMO. I would love to customize the iDrive and would be willing to invest in the above hardware if I'd be able to:

• Visualize my own sensors for engine monitoring purposes
• Watch DVDs while driving
• Do the CD-MP3 encoding with my own format preferences and choose target for saving and playback
• Add my own codecs so I can watch DiVX/XViD-encoded movies (5-7 movied would fit on a Data DVD)
• Offer an alternate NAV option that uses the Google Maps API and updates points of interest/local businesses etc using your phone (see below)
• Android integration(!)... the NexusOne is an amazing little unit and will soon get a car dock. iDrive integration/updates via 3G would rock.
• Add Bluetooth if your car doesn't have it
• ...much more

All of the above should have an iDrive feel and be offered as additional menu options.

I've been thinking about this for a while, as I said in another thread... I'd love to have the time to tinker with this and see how it all works to gauge feasibility.

Thoughts? Thank you for the info cstavaru, this module seems worth looking into!

-Walter

I would definitely like to see data but IMO, the control is better left to a dedicated CPU but with COMs to a unit which can display data on the iDrive screen.

Hey Walter, we could start with my PROcede car, especially since it has CAN data already and adapt to others.