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Running Tesla Model 3's computer on my desk using parts from crashed cars

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Re: Running Tesla Model 3's computer on my desk using parts from crashed cars

#241

Post by fc417fc802 »

CalRobert wrote: post #218
fc417fc802 wrote: post #175

Earlier quoted context omitted.

Then why wasn't it a problem before? People have always been able to install aftermarket or possibly even hacked together physical parts. If there was liability you'd expect some sort of shield blocking access to, for example, the hydraulic system for the brakes. As it turns out though blatant irresponsibility is quite rare (depending on your definition anyway) since people have a strong self interest in not endanger…

People get killed by changes to exhaust, height (lift kits), bumpers (bull bars in particular), etc pretty often, though. And I can imagine software changes (exhaust is part of that actually) could kill people too. Maybe you think daytime running lights are stupid and want to disable them for instance.

Sure. Point is nothing has really changed. Largely there's no problem and to the extent that bad things happen it isn't something novel that's only just come up. It's not in and of itself an excuse to erode private ownership. If intervention is required then regulation should be passed deliberately by the legislature.

Re: Running Tesla Model 3's computer on my desk using parts from crashed cars

#242

Post by bluGill »

pta2002 wrote: post #230
jabedude wrote: post #131

I'm actually somewhat surprised the OS fully boots when it's not connected to the expected vehicle peripherals

I work on automotive software (not Tesla), and it's like this partially because it makes development _way easier_. Rather than needing to get a whole car to the dev team, you just give them the specific part that they're working on. Anything that needs outside features usually just fails gracefully (e.g. no speedometer or no location for maps). These are usually mocked for testing, or you add the specific ECU that pr…

I work on that software too (again not Tesla). One other thing - often the hardware we get is per-production and has a list of errata that will be fixed before production. They don't want to make too many of these for engineers because it is done in a fast turn-around higher cost factory and it is expected that once in a while things won't work at all (someone forgets to connect power to the CPU pin or something similarly stupid that requires a lot of manual wiring to fix on each one). As such you have to justify getting any controller and often share. Once the product is shipping they make many of them and it isn't a big deal to get one on your desk - but you have now moved onto the next thing and so the problem returns.

Re: Running Tesla Model 3's computer on my desk using parts from crashed cars

#243

Post by bluGill »

yc-kraln wrote: post #188

I would love to use the drive units from a Tesla in a conversion project. Unfortunately, they're cryptographically paired with the main computer, and there's no way to use them. What a waste.

That is done to kill the "chop shops" criminals used to steal cars and then break them up for parts. You can't do that with computers because of that pairing and so stealing a car pays much less and in turn is less common. (it still happens, it just doesn't pay as well)

Re: Running Tesla Model 3's computer on my desk using parts from crashed cars

#244

Post by bluGill »

completelylegit wrote: post #56

People need to request the source code.. There’s a ton of open source they use that forces Tesla to give you source if you’re a customer and you ask. I don’t get why security people aren’t doing this already.

You get the linux kernel and a bunch of other things you can find on github anyway. You can't do anything useful with that, except what you already can get from any linux package manager.

Sure someone should do it just to verify the process works, but it isn't really useful. (in general companies are very careful to not violate GPL license terms, often refusing to use GPL3 at all)

Re: Running Tesla Model 3's computer on my desk using parts from crashed cars

#245

Post by cj »

fc417fc802 wrote: post #241
CalRobert wrote: post #218

Earlier quoted context omitted.

People get killed by changes to exhaust, height (lift kits), bumpers (bull bars in particular), etc pretty often, though. And I can imagine software changes (exhaust is part of that actually) could kill people too. Maybe you think daytime running lights are stupid and want to disable them for instance.

Sure. Point is nothing has really changed. Largely there's no problem and to the extent that bad things happen it isn't something novel that's only just come up. It's not in and of itself an excuse to erode private ownership. If intervention is required then regulation should be passed deliberately by the legislature.

I dunno, I think there's a big difference between making digital modifications to software vs. making physical modifications to hardware.

The risk profile is very different and non-obvious to your average car owner.

It's the difference between trying to repair your leaky dishwasher vs. trying to repair the electrical panel in your basement.

Re: Running Tesla Model 3's computer on my desk using parts from crashed cars

#246

Post by cucumber3732842 »

imp0cat wrote: post #151
K0balt wrote: post #109

Earlier quoted context omitted.

The nominal range for automotive systems is 10-16v. If you are designing anything for automotive use that doesn’t work reliably in that range, you are manufacturing problems for people.

This. Most cars nowadays come with the so-called "smart" alternators that vary voltage wildly depending on the current driving conditions. One minute you might be accelerating and the onboard voltage drops as the battery supplies most of electricity. Then, as you reach the crest of a hill and start engine-braking, the car frantically tries to convert all the available kinetic energy to electricity, raising the onboar…

>This. Most cars nowadays come with the so-called "smart" alternators that vary voltage wildly depending on the current driving conditions.

Which in practice means that they do a very miserly job charging the battery and are a ton more sensitive to a battery being in less than tip top shape so you can expect your battery lifetime to go down.

But it's a "win" because they pushed the serp belt change outside of whatever interval the reviewers who calculate TCO care about and they saved .000003mph in the process.

Re: Running Tesla Model 3's computer on my desk using parts from crashed cars

#247

Post by uticus »

> We ordered the chip and took the board to a local PCB repair shop, where they successfully replaced it and fixed the MCU.

What is a "local PCB repair shop"? All the guys who used to fix TVs and radios are gone. Anyone else (not living in China) having trouble locating such an outfit in their neighborhood?

Re: Running Tesla Model 3's computer on my desk using parts from crashed cars

#248

Post by WarmWash »

uticus wrote: post #247

> We ordered the chip and took the board to a local PCB repair shop, where they successfully replaced it and fixed the MCU. What is a "local PCB repair shop"? All the guys who used to fix TVs and radios are gone. Anyone else (not living in China) having trouble locating such an outfit in their neighborhood?

Cell phone/laptop repair shops.

Re: Running Tesla Model 3's computer on my desk using parts from crashed cars

#249

Post by uticus »

> Turns out that actual cars don’t have individual cables. Instead they have these big “looms”, which bundle many cables from a nearby area into a single harness. This is the reason why I could not find the individual cable earlier. They simply don’t manufacture it.

Typical setup for cars (and lawn mowers). As a software guy my first instinct is, computing power is cheap enough, seems like a CAT5-like thing running between all components would do it. Speaking as a software guy - meaning I'm probably missing a lot of the big picture. On the other hand, it's a lot easier to safety-check a mechanical lockout that physically opens a circuit, than something running on software.

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