Bluetooth question

Tleg93 · Post by **Tleg93** » Thu Feb 19, 2004 3:45 pm

After soldering around in a friends wiring harness this weekend to install vrg's FCD a thought crossed my mind. Would it be possible to use bluetooth or some other wireless technology to replace some of the elements in the wiring harness in order to reduce the amount of wires present? I'm sure that automakers have at least considered this idea. Maybe it's the laws against EMI that prevent it, anyone know????

vrg3 · Post by **vrg3** » Thu Feb 19, 2004 4:18 pm

I haven't heard much about intra-car wireless networking research... The current state of the art is stuff like CAN (Controller-Area Networking) where many parts of the car have intelligent controllers that are all connected together with a wire bus. When I hook my laptop up to my friend's 98 VW Jetta TDI's OBD-II port I can talk to his radio, for instance. It's a bus, so it does somewhat simplify the wiring because the same wire goes to every device.

I don't think automakers feel a need to reduce the number of wires. Wires are a well-proven reliable way of connecting things. :) They're easy to follow visually and easy to inspect both visually and electrically. And, they're inexpensive.

With any kind of wireless setup you'd have to worry about making sure the signal gets through even when there's background noise, but also not making it so strong that nearby cars of the same configuration are affected. You need to provide some element of security since otherwise anyone who was near your car could affect or take over your systems. You'd have to either design a different system for different countries or make sure your system conformed to the radio regulations in every locale in which your car was sold.

From what I understand, automotive engine computers and the like are built to be much more resistant to EMI than consumer-grade computing hardware. Achieving the same ruggedness may be impractically hard when using wireless technology.

These are just guesses, though... and I'm sure some good engineering could take care of a lot of these issues. So maybe one day we'll start seeing that stuff. I hope I never own a car like that, though, since I like wires. :)

The proposed OBD-III standard will actually incorporate some wireless capability. I guess the intent is to eliminate the physical diagnostic port while simultaneously making it harder for ordinary mortals to access their own cars. In any case, I believe the functionality will be similar to the current OBD-II scantool interface except that there won't be wires. Some people are scared of what it might mean, though... The federal government is going to mandate that you have a system in your car that can broadcast things like the current vehicle speed to anyone nearby with the right kind of receiver. They've already tested little boxes not unlike speed cameras that sit at the side of the road and automatically write tickets for failed emission control devices -- if you drive past one of these with a CEL on, you get a ticket in the mail. (That may be a bit dramatic; they haven't yet done anything other than just test these devices so we don't know exactly how they will use them. How much can you trust these people, though?) These things can monitor four lanes of traffic moving at highway speeds, too.

Yeah, I'm being a little alarmist...

evolutionmovement · Post by **evolutionmovement** » Thu Feb 19, 2004 5:49 pm

I have Libertarian tendencies myself and what I've read about OBDIII scares me to death. I'll build my own car before I'd by something with OBDIII. I've read that the car will automatically notify the DMV of emissions non-compliance and they'll send you a notice by mail that you have 10 days to fix it before registration revocationa nd fine. Plus they'll have access to all other auto systems. Think of weight detecting air bag sensors (how many and approx. weight of pass), vehicle speed, location (GPS navigation), and the likely ability to shut your car down remotely. They try that on me they'll catch a good ol' fashioned mechanical shotgun blast to the face. He may just be doing his job, but tell that to victims of the Gestapo. All this and the EPA is just getting around to regulating trucks, boats, motorcycles, and small engines. What about every time we send something into space?

Steve

boostjunkie · Post by **boostjunkie** » Thu Feb 19, 2004 6:07 pm

Never thought I'd say this . . .

Better buy an OBD2 car.

Tleg93 · Post by **Tleg93** » Thu Feb 19, 2004 6:27 pm

Yeah, that's pretty stagering to think about. I guess I would rather have the traditional wiring harness considering all those other factors that were mentioned by vrg. Up until now I haven't heard about this OBDII but from what you're telling me I don't like the sound of it one bit (or byte for that matter

). I love technology but when it gets to the point of a Technocracy I start to have plenty of doubts about it being for our betterment. I think maybe good old fashioned wires are better considering the alternative.
My thought about the wiring harness is that there's no 'service loop' to work with. It seems like those wires are designed to be just long enough with nothing to spare but I guess they saw no reason why anyone would want to mess with it.

off topic thoughts:
With this OBDIII it sounds like some elements are again devising ways to rob us of independent thought and exert a dictatorial control over every aspect of society. I think that maybe we are developing too fast technologically for society to keep pace. Thing is, once you bring a technology into being you can't uninvent it so we should be careful how much control we exert over soceity or we could wind up in a world that would make 1984 look like a free society. I've seen things on TLC and discovery that amaze and scare me. I could go on and on but I won't....(No one wants to hear it anyway

)

evolutionmovement · Post by **evolutionmovement** » Thu Feb 19, 2004 8:34 pm

I think they only use just long enough wires because longer ones would cost more, but more importantly, packaging larger bundles would be more difficult.

I don't mind hearing about it. I'm a firm freedom over safety or convenience person.

As Franklin said, "Those that would give up freedom for security deserve neither."

Steve

JasonGrahn · Post by **JasonGrahn** » Thu Feb 19, 2004 11:44 pm

Padishar Creel wrote: Would it be possible to use bluetooth or some other wireless technology to replace some of the elements in the wiring harness in order to reduce the amount of wires present?

Insider sources have informed me that Microsoft is working on this application already.

georryan · Post by **georryan** » Fri Feb 20, 2004 1:58 am

Off Topic:

I live in my own little world. But it's OK...they know me here.

LOL

Tleg93 · Post by **Tleg93** » Fri Feb 20, 2004 3:31 pm

I guess I should have named the topic "wireless question"

. My humble point with the wiring harness is that if there's something shorted out within the harness it's generally not an easy task to find it. It would be nice if it was more accessible or simplified in some way cuz that's a huge mass of wires in there. I'm pretty sure the harness is rarely an item that is defective but it doesn't hurt to ponder the possibilities. What can you do though? Almost anything I could come up with is probably already researched at Subaru.

vrg3 · Post by **vrg3** » Fri Feb 20, 2004 6:40 pm

Short circuits aren't usually that hard to find if you have a good reference to use. It's intermittent problems that are a pain.

czo79 · Post by **czo79** » Fri Feb 20, 2004 8:47 pm

I do not want microsoft coming anywhere near my car...
it just will not be cool to be driving down the road and have your car lock up...

JasonGrahn · Post by **JasonGrahn** » Fri Feb 20, 2004 8:59 pm

czo79 wrote:I do not want microsoft coming anywhere near my car...
it just will not be cool to be driving down the road and have your car lock up...

You may find this funny then: http://www.netropolis.au.com/networks/t ... _cars.html
http://www.engr.mun.ca/~whitt/humor/microsoft.html

Tleg93 · Post by **Tleg93** » Fri Feb 27, 2004 3:25 pm

In rethinking, I guess that a short in the wiring harness wouldn't usually be too hard to find compared to an open but, in comparison to other car problems, I don't think it's very easy to replace or troubleshoot shorted or opened wires in a wire harness.

Dr Nick · Post by **Dr Nick** » Fri Feb 27, 2004 10:33 pm

An aside- BMW have just released a motorcycle in europe where some of the wiring loom (like to the back lights) is a single wire. I haven't read up much about it but I guess it uses fibre optics or something (like Cable TV) to run a bunch of different signals up the same piece of cable.

I don't like the idea of wireless networking in my car - what happens if someone hacks your network from the car next to you? I guess it would add a new dimension to the "stop light grand prix". It would be a race to disable the car next to you before the lights change...

Like others on the forum I find the whole concept of being monitored all the time pretty worrying. I mean you buy a Tracker for your car so that they can find it if someone steals it, but it also means you can be monitored if they choose to do so. My brother-in-law's company track their vans by the same method so that they can tell who's working where, how long they spent on each job, who went home early yada yada yada (Seinfeld reference!)

They're not happy about it but what can you do?

vrg3 · Post by **vrg3** » Fri Feb 27, 2004 10:45 pm

Is this the bike you're talking about?

http://www.bmwmoa.org/features/newmodels/r1200gs.htm

It sounds like CAN... Maybe it actually is CAN or is a proprietary form of it.

As for winning a red light race with electricity, you already could, in principle. A strong enough EMP would immobilize an EFI car. As I recall there are people actually developing these things to sell to law enforcement as alternatives to spike strips.

Makes me wish I still had my '84 Mercedes 300D.

evolutionmovement · Post by **evolutionmovement** » Sat Feb 28, 2004 12:35 am

I saw that too, they were developing an R/C car that they would pilot under a moving vehicle and knock it out with an EMP. Another reason to run off into the hills to live, build a steam car and wait for the infrastructure to collapse. Then I will be KING! KING I say! HAHAHAHAHA!

Steve

JasonGrahn · Post by **JasonGrahn** » Sat Feb 28, 2004 1:17 am

http://www.pcmag.com/article2/0,4149,1476582,00.asp

vrg3 · Post by **vrg3** » Sat Feb 28, 2004 1:21 am

Hmm, yeah... they're using Bluetooth for accessories (cell phones in this case), which aren't critical.

It's saddening to see so much cost and effort going into something that's fundamentally a bad idea though. Talking handsfree while driving isn't much safer than talking with a handset while driving.

Dr Nick · Post by **Dr Nick** » Sat Feb 28, 2004 2:43 am

vrg3 wrote:Is this the bike you're talking about?

http://www.bmwmoa.org/features/newmodels/r1200gs.htm

That's the very one! Thanks vrg3

Tleg93 · Post by **Tleg93** » Mon Mar 01, 2004 4:18 pm

Hey vrg3, I was wondering if you could point me to a resource that describes CAN's in detail. I've had to troubleshoot PCB's with CAN chips on them. When the CAN chips caused PCB test failures OTJ it was usually a solder short or lifted pins. I've read about them to some degree but I haven't yet found a resource that explains what form the transmitted data takes. I'm thinking of regular IP packets but I really don't know. Thanks for any help.

vrg3 · Post by **vrg3** » Tue Mar 02, 2004 4:23 am

I don't really know much about CAN except that it's crazy complicated. :)

Okay, actually, I do know this much -- It is a broadcast kind of medium. I believe it uses CSMA. The packets aren't IP; they're a different much simpler form. I don't know much about how devices identify themselves but I do know each packet can have a payload of up to 8 bytes. I believe they are transmitted using a NRZ pattern kind of like RS232. ([DrEvil] Pretty standard, really. [/DrEvil]) I might be wrong though; it may be more complex.

I don't know anything about actual CAN controller chips.

As far as resources, I only have one to offer:

http://www.google.com/search?q=controll ... etwork+can

:)

Tleg93 · Post by **Tleg93** » Tue Mar 02, 2004 3:55 pm

Thanks a bunch, I didn't know that they used CSMA. I've read data sheets for the IC's and they cover pinout descriptions, voltage levels, etc. but it never led to an understanding of how they actually function. I've read a few papers on CAN controllers but sometimes technical papers on IC's can be a little obtuse. Thanks for the link, I'll check it out.

vrg3 · Post by **vrg3** » Tue Mar 02, 2004 5:21 pm

Yeah, I know what you mean about the papers. Sometimes it seems like they publish them because they have to, but they write them in such a way as to give away as little information as possible.

Tleg93 · Post by **Tleg93** » Wed Mar 03, 2004 7:45 pm

I'm not sure how I missed it before but it's possible that I just didn't perform a good search last time I tried to look up info on CAN's. It's also possible that good documentation didn't exist at that time either (doubtful). Whatever the reason is, I found some literature on CAN and I thought maybe vrg3 and others might be curious and check it out. I realize that everyone is fully capable of finding it on their own but here's a couple links anyway.

http://www.can.bosch.com/index.html

http://www.microchip.com/download/appno ... 00713a.pdf

The bosch site is cool because it has a pic of a car on the homepage and it gives a good overview, interesting site too. I didn't realize the OSI model applied, I guess that's why it's universal to all networking protocols...?

vrg3 · Post by **vrg3** » Wed Mar 03, 2004 7:56 pm

Cool, thanks for the links.

I thought the OSI model was meant to apply to all networks. It's just that some have degenerate forms of certain layers.

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