ALL CyberTruck discussion

[mongo]

You are almost certainly right. I'm betraying my non-automotive data comm roots. There are indeed single and dual pair copper ethernet standards for automotive use. As well as cheap plastic fiber optic Ethernet for automotive. In they used copper, they could also provide power over that too. The coolest implementation, I guess, would be fiber optic with separate power. Why would you think dual pair, why one just one pair if they used copper?

Optical requires more work at the termination side.
Two pairs gives redundancy which is critical with steer by wire and progression to FSD. Tesla has a patent application that uses a ring that still gives full connectivity if one link fails. Two pair may be overkill, but preserves bandwidth rather than dropping to half duplex. Also, the application also showed a dual pair harness crossection.
They can power over the comm lines, but the vehicle main bus power needs are higher than the usual 50W (though for an end node, that may be fine). Twisted pair wire gauge vs power requirements.

If they are building all their own modules, then yes, sure would be easier! Would be fascinating to read more about the data comms protocols that Tesla uses.

UDP is pretty decent, just need to add a fault tolerant layer on top. Dragon uses Ethernet too, I think.

 

[Cosmacelf]

UDP is pretty decent, just need to add a fault tolerant layer on top. Dragon uses Ethernet too, I think.

Yeah, I was thinking of the application layer protocols. Interesting that you bring up UDP though. Web traffic is slowly migrating to using UDP with a fault recovery protocol (QUIC) on top. It is better than TCP for a whole bunch of reasons. That too would be interesting to see what Tesla is using.

 

[BioSehnsucht]

In addition to power limitations, implementing PoE is also a pain due to the additional components required to separate the power from the data signaling. So I'm not sure where the trade off would be for module cost (PoE) vs wiring cost (separate power), but probably not as many PoE devices as there could be even under the power limitations.

 

[mongo]

Yeah, I was thinking of the application layer protocols. Interesting that you bring up UDP though. Web traffic is slowly migrating to using UDP with a fault recovery protocol (QUIC) on top. It is better than TCP for a whole bunch of reasons. That too would be interesting to see what Tesla is using.

Yeah, a lot of data transmitted has the characteristic of the most recently value being important and the older ones being useless. So retry within window, but don't stall on a stale packet. Not that I expect a lot of bus contention.

 

[mongo]

In addition to power limitations, implementing PoE is also a pain due to the additional components required to separate the power from the data signaling. So I'm not sure where the trade off would be for module cost (PoE) vs wiring cost (separate power), but probably not as many PoE devices as there could be even under the power limitations.

Vanilla PoE is practically free if you already have center tap isolation transformers.
Power over data line on automotive ethernet can put positive and negative on one pair.

The Art of Networking (Series 10): Power over Data Line is ready to use

 

[BioSehnsucht]

Vanilla PoE is practically free if you already have center tap isolation transformers.
Power over data line on automotive ethernet can put positive and negative on one pair.

View attachment 996128
The Art of Networking (Series 10): Power over Data Line is ready to use

Even if cheap in price they take up space that may be an issue for many smaller modules.

 

[Cosmacelf]

Yeah, a lot of data transmitted has the characteristic of the most recently value being important and the older ones being useless. So retry within window, but don't stall on a stale packet. Not that I expect a lot of bus contention.

Yes, for certain applications, like wanting to know the current accelerator position, its probably pointless retransmitting the fifth packet ago if you have the current one.

I do wonder how much custom communications code Tesla has written.

While I realize this example is at the complete other end as far as mission critical goes, it always bugged me that the Tesla browser code still kept the concept of selecting in the touch screen UI. It would actually allow you to select words on the browser, just like an iPad would. But there was no UI ability to cut/copy/paste, so that left over functionality was not only useless, but actually hindered use since it would invariably select something when I meant to press something.

I just checked and the in car browser still does this. If you press on a link a little too long, it interprets it as selecting the link and changes the link color, but doesn't traverse the link. If you press it quickly, it'll traverse the link. WHY???

 

[mongo]

Even if cheap in price they take up space that may be an issue for many smaller modules.

Yeah, that's why I don't expect a lot of small networked modules. Rather, medium duty zone modules on the network that drive the loads and read the inputs.

 

[jabloomf1230]

Yeah, Tesla somehow had to find/build 48V headlights, door window motors, latch releases, blower motors, seat heaters, ambient lights, etc. I really want to learn how they did it. I also wonder if Tesla has considered becoming a 48V parts supplier to the industry?

Aren't LED headlights comprised of individual LEDs in series? It seems like it wouldn't be that hard to make headlight units of any voltage by combining individual LEDs into series and parallel banks.

 

[Cosmacelf]

Aren't LED headlights comprised of individual LEDs in series? It seems like it wouldn't be that hard to make headlight units of any voltage by combining individual LEDs into series and parallel banks.

I really don’t know much about the vehicle parts industry, but it seems that headlamps are fairly customized for different vehicles, and the CT has very unique looking headlights. So the CT headlights may indeed be a custom part, and at that point, it would indeed be easy to order it made to work at 48V. Unless Tesla made them in house themselves, which is always possible with Tesla.

 

[mongo]

Aren't LED headlights comprised of individual LEDs in series? It seems like it wouldn't be that hard to make headlight units of any voltage by combining individual LEDs into series and parallel banks.

Yeah, especially for white color matching, LEDs are configured in series so they all get the same current. Strings may be in parallel. Individual LEDs directly in parallel need good matching.
High output LED modules are often an array of LED die on one chip.

With 48V, as long as the LED's forward voltage is less than 48V, it's easy to control the current (brightness) and on/off state with a simple buck converter (switch, inductor, diode, capacitor).

 

[mongo]

Ot but it is the weekend. Muzzle velocity is +/- 10-50 feet per second affected by a suppressor which is negligible. The penetration power has more to do with the type of ammunition used (ie. Low grain full metal jacket practice ammo that's subsonic vs +p armor piercing supersonic rounds). Experience from vehicle interdiction and ammo testing with a large city special weapons team.

Anecdotally several of us are patiently waiting in line for our personal reservations of cybertrucks.

Data from video
Speed of sound (feet per second): 1125
Glock 9mm 115 grain subsonic round: 1100
MP5-SD, 9mm 115 grain: 950
Tommy Gun .45: 935
M4 12 gauge shotgun, 00 buckshot:??? (1000+?)

The SD version of the MP5 has an integrated suppressor. Dialog says 4 inch barrel, 8 inch suppressor.

https://twitter.com/x/status/1730405000608661527

 

[Buckminster]

https://twitter.com/x/status/1731553681818980455

 

[Buckminster]

https://twitter.com/x/status/1731515130834300976

 

[Doggydogworld]

https://twitter.com/x/status/1731553681818980455

Single motor will likely be cancelled because "our data showed it only made up 7% of orders".

 

[FastEddieB]

https://twitter.com/x/status/1731553681818980455

I doubt that. Outside of cities, trucks are likely to regularly find themselves on gravel and dirt roads and construction sites. AWD is a big benefit there.

 

[Cosmacelf]

I doubt that. Outside of cities, trucks are likely to regularly find themselves on gravel and dirt roads and construction sites. AWD is a big benefit there.

What’s the stats on ICE pickups?

 

[FastEddieB]

What’s the stats on ICE pickups?

Single data point: our Ridgeline is AWD, and it’s much appreciated. As is our Ford Flex tow vehicle.

 

[jebinc]

https://twitter.com/x/status/1731553681818980455

Really tough to believe anything the Whole Mars Catalog shill says - Ever watch his FSD Beta videos?!

 

[willow_hiller]

Delivery event on Thursday, and already someone is trying to flip one. I'd be curious to see how much this actually sells for, but unfortunately, it being listed on Craigslist, I don't think we'll get much insight:

EDIT: Removing the link just in case it's a Bitcoin scam (they're requesting a non-refundable $10 BTC transfer to be taken seriously), but here's the text and image copied for posterity:

TESLA CYBERTRUCK TRI-MOTOR BEAST - $110,000 (fremont / union city / newark)

I am selling my cybertruck IN HAND due to the fact that my spouse hates it and cannot park it. Yes, I picked it up in Texas at the release event and had the car transported via covered carrier to get it back to me here in Fremont. I am attempting to recover my costs and transportation. Due to the amount of inquiries, there are some simple details below.

Sad to see it go, taking offers over $110,000. Be one of the first to have, think of the social medial possibilities.

Only accepting Bitcoin ...