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Standardizing Automotive Connectivity

tesla.com

171–180 of 182 posts

Re: Standardizing Automotive Connectivity

#171
post #55

Those look much like AMP automotive connectors. Using one kind of unkeyed connector in a car may be a bad idea. Things can be plugged in wrong during repairs. There's a lot to be said for making connectors not fit where they shouldn't. Especially in automotive, where many connectors are plugged in blind, by feel. This simplifies manufacturing at the cost of repair. If it can be plugged in wrong, it will be plugged in…

Actually there’s two paths: first the traditional path of different unique wiring harnesses and various signals with unique connectors, or second a common power and coms bus design. If the Cybertrucks electrical ethos is followed by others there’s only 48V and Ethernet. Ethernet doesn’t care or fry if plugged into a wrong port. Any complex wiring can be done inside a part or component as needed, but the interface is…

Even Cybertrucks aren't purely 48V and ethernet.

There's a high voltage (800V) rail for high current devices like the AC compressor. There's redundant CAN for communication with things like the motors. There's a host of 12V, 16V, 5V components (door locks, lights, seat motors, etc.).

They did switch many components to 48V, but not literally everything.

Re: Standardizing Automotive Connectivity

#172
post #55

Those look much like AMP automotive connectors. Using one kind of unkeyed connector in a car may be a bad idea. Things can be plugged in wrong during repairs. There's a lot to be said for making connectors not fit where they shouldn't. Especially in automotive, where many connectors are plugged in blind, by feel. This simplifies manufacturing at the cost of repair. If it can be plugged in wrong, it will be plugged in…

Nah, these look like keyed Deutsch DTM connectors. They are very obviously keyed, so not sure why you say unkeyed.

This will never take hold. These are extremely expensive vs weatherpack and other cheap connectors. Auto manufacturers care about literal pennies.

Re: Standardizing Automotive Connectivity

#173

Earlier quoted context omitted.

> If the Cybertrucks electrical ethos is followed by others there’s only 48V and Ethernet. I'm looking at the electrical schematic [1] and 'eth' appears 107 times while 'CAN' appears 805 times. And if you think about it, you probably don't want your brake-by-wire system to share a bus with your sound system and your trunk latch for obvious reasons. [1] https://service.tesla.com/docs/Cybertruck/ElectricalReferenc...

Cool, thanks! It looks like the cybertruck does extensively use CAN still. Tesla only talks up Ethernet. Makes sense, though I’m a bit bummed. > And if you think about it, you probably don't want your brake-by-wire system to share a bus with your sound system and your trunk latch for obvious reasons. Sharing a bus for those two wouldn’t make sense. However Ethernet topology wouldn’t preclude having those on separate…

> However Ethernet topology wouldn’t preclude having those on separate buses and linked via switches

The topology might not care, but someone designing a trunk latch that communicates via Ethernet might get a visit from an annoyed representative from Value Engineering.

Re: Standardizing Automotive Connectivity

#174
post #11

They would have to 100% open this up and give it to standards bodies, otherwise it isn't a standard. The conformity tests and testing equipment designs and protocols should be freely available.

For that matter: who's going to be manufacturing and supplying these connectors? Tesla? I don't think so.

Anyone really. If you look at the quick connect fittings commonly found on German cars they're all built to a standard (VDA not DIN in this case) but built by the NORMA Group or Parker.

Re: Standardizing Automotive Connectivity

#175
post #141

Earlier quoted context omitted.

With ethernet you can probably run the car software in containers. I can imagine a container to simulate each hardware unit, a small inter-contaner lan, and develop code that way.

You can already do this trivially with Linux vcan[1] so I don't buy this argument. I think the bigger factor is that innovation in the CAN ecosystem has been lagging behind Ethernet for decades now. Only reason it's had such staying power is industry inertia. 1. https://netmodule-linux.readthedocs.io/en/latest/howto/can.h...

The relative cost is probably a factor (which overlaps with inertia of course, but if the thing you already have implemented is also cheaper, you aren't going to hurry up and change).

Re: Standardizing Automotive Connectivity

#176

Earlier quoted context omitted.

Name the “wildly successful” standards you are thinking of and then look into the history of them. You’ll find one or maybe two major players that pushed it initially.

Ok? I'd rather trust DARPA than private enterprise.

You didn’t name any.

BGP, 802.11, QUIC, HTTP, SSH all came from dominating implementations.

Re: Standardizing Automotive Connectivity

#177
post #55

Those look much like AMP automotive connectors. Using one kind of unkeyed connector in a car may be a bad idea. Things can be plugged in wrong during repairs. There's a lot to be said for making connectors not fit where they shouldn't. Especially in automotive, where many connectors are plugged in blind, by feel. This simplifies manufacturing at the cost of repair. If it can be plugged in wrong, it will be plugged in…

Nah, these look like keyed Deutsch DTM connectors. They are very obviously keyed, so not sure why you say unkeyed. This will never take hold. These are extremely expensive vs weatherpack and other cheap connectors. Auto manufacturers care about literal pennies.

Well that's a lot to unpack. Saying AMP connectors doesn't really mean much of anything because, for starters, AMP (TE Connectivity) owns Deutsch.

In the retail space, at least, DTM's largely been superseded by the lower-cost ATM line. Weatherpack and Metripack are pretty common in the US because GM developed them and GM is a huge company. The only company that comes to mind for using DTM connectors is Caterpillar, so you'll definitely see medium duty trucks with DTM assemblies.

The two automotive companies I'm most familiar with (80s Volvos and 00s BMWs) use keyed connectors all over the place. The Volvos used off-the-shelf washing machine connectors (AMP /(junior )+(power )+timer/) that can be had with keyed connectors. BMW saved pennies by going with high density connectors and small gauge wire. Most of that stuff is off-the-shelf as well, but often with proprietary keying.

Both DTM and Weather/MetriPack are pretty bulky compared to what's available now though, and when you're talking about 100 or 200 pin connectors size probably matters more than a few pennies. And, of course, once you start adding the retention doodads to MetriPack assemblies you start getting closer in price to DTM style stuff. The simplicity of the wedgelock design means fewer parts to stock and potentially faster assembly which could easily negate the more expensive housings.

Re: Standardizing Automotive Connectivity

#178

Earlier quoted context omitted.

Cool, thanks! It looks like the cybertruck does extensively use CAN still. Tesla only talks up Ethernet. Makes sense, though I’m a bit bummed. > And if you think about it, you probably don't want your brake-by-wire system to share a bus with your sound system and your trunk latch for obvious reasons. Sharing a bus for those two wouldn’t make sense. However Ethernet topology wouldn’t preclude having those on separate…

> However Ethernet topology wouldn’t preclude having those on separate buses and linked via switches The topology might not care, but someone designing a trunk latch that communicates via Ethernet might get a visit from an annoyed representative from Value Engineering.

Haha touché. However unintuitive as it may seem an ethernet based trunk latch could be overall cheaper from a system level than a straight relay based system or even CAN system.

Especially with the newer two wire ethernet with power via 10BASE-T1S. The connector likely costs more than the ethernet chip, and microprocessors can be had for nickels. So at large manufacturing scale it could easily cost less to share a single ethernet and power line and save on wiring, connector complexity, etc.

Re: Standardizing Automotive Connectivity

#179
post #18

Tesla really deserves some kudos for pushing the 48V architecture and the Ethernet-based communication. It drastically simplifies the wiring mess that is in a typical car. And it's not even close. Just watch the teardown of Cybertruck and compare its wiring to something like F150.

> Tesla really deserves some kudos for pushing the 48V architecture and the Ethernet-based communication.

And some schooling. They shall learn about pokayoke.

Re: Standardizing Automotive Connectivity

#180
post #90

Earlier quoted context omitted.

> Tesla really deserves some kudos for pushing the 48V architecture and the Ethernet-based communication. For the record, 42V systems were experimented with in the 1990s: * https://en.wikipedia.org/wiki/42-volt_electrical_system In the 2011 German automakers agreed to 48V as the next step after 12V: * https://en.wikipedia.org/wiki/48-volt_electrical_system BMW was the first the first with Ethernet: * https://www.marv…

This has been a real head-scratcher for me. BMW and other automakers could have vastly improved their cars by switching to 48V a decade ago, but they still keep just plodding along with 12V. I have no explanation for this.

> automakers could have vastly improved their cars by switching to 48V a decade ago,

The microcontroller still runs at 5/3.3/1.8 V.

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