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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

#61

Post by nandomrumber »

ferongr wrote: post #4
LikeBeans wrote: post #3

Very cool. Over a year and a half ago I installed a towing brake controller in my Tesla Model Y. Found the location of the plug, how to access and the pinout online (confirmed via a voltmeter..) so the car's side felt straight forward. But then I needed to find a brake controller that can work with the higher voltage (14.4v vs the normal 12v). Then built a cable from the brake controller to the connector that plugs i…

>then I needed to find a brake controller that can work with the higher voltage (14.4v vs the normal 12v) Put a voltmeter on the battery terminals of a regular car at 2000rpm and note the voltage. You'd be surpised (the alternator can produce as high as 15V on some cars).

I typically fault anything above 15.6V as “that’s a bit high, your alternator might be on its way out” when working on automotive / caravan / camper van appliances and accessories.

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

#62

Post by nandomrumber »

mixdup wrote: post #45
AlotOfReading wrote: post #20

Earlier quoted context omitted.

Automotive transients can be wild. I did a bringup with a board that had specified 100+v range specified for transients and finicky quality requirements on the output. The power supplies took up most of the (very large) board.

14v is not a transient, if your voltage was 12v with the car running, there's something wrong with the charging system (DC-to-DC in an EV, alternator/generator in an ICE) 13-14v is normal in all 12v automotive systems as the charging voltage

If I recall correctly, a fully charged lead acid battery has an open circuit voltage of 13.6V.

So the alternator has to put out at least something higher than if it’s planning on recharging the battery after 500 to 700 amps have been pulled from it for a few seconds to start the engine.

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

#63

Post by dwa3592 »

Interesting.

> A REST-like API on :8080 which returned a history of “tasks”

I am curious to know what kind of historical tasks- since it's a media control unit; does it show what kind of media was being played in the last trip? does it reveal any other info about the driver?? There might be a privacy angle here that you could exploit and share it with Tesla.

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

#64

Post by longislandguido »

spuz wrote: post #44
kube-system wrote: post #13

> 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. I was really surprised to read this at the end of the article -- how could someone be this deep into a project of this depth and not realize this?! Not o…

Even if you know that cars consist of a single wiring harness, it's not implied that they aren't modular and the individual cables cannot be purchased separately.

[flagged]

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

#65

Post by FireBeyond »

kube-system wrote: post #13

> 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. I was really surprised to read this at the end of the article -- how could someone be this deep into a project of this depth and not realize this?! Not o…

> and to Tesla's credit they have amazing free docs

Not to Tesla's credit, they had to be dragged kicking and screaming into it (primarily by Massachusetts) and their right to repair legislation through a solid chunk of malicious compliance:

1. When told that they had to have a site for people to order parts, Tesla put up a site that had every single item as "Call us", including the most simple of bolts. And when a few places called, "Sorry, that's not available to you".

2. The service manual was originally only available in a few locations in MA, and had strict conditions: you had to book in advance, there was a $100 fee per booking, and you could only view the manual on premises, and could not bring electronic devices into the room with you, just pen and paper.

The docs they have are great, and who knows how their attitude would have changed over time, but they absolutely didn't want you to have it, initially.

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

#66

Post by msisk6 »

kube-system wrote: post #43
MBCook wrote: post #37

Earlier quoted context omitted.

I will say I’m surprised how far apart the two boxes are in the car. I guess they’re not where I thought. I would assume they’re both up near the dash.

The passenger side kick panel or behind the glove box are two very common places for vehicle computers -- some cars have them under the hood, which I always thought was a bad idea.

My RAM truck with the Cummins diesel engine has the engine computer mounted on the engine block. You'd think the heat and exposure to the elements would make that a bad idea, but I suppose Cummins knows what they're doing.

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

#67

Post by sneakymichael »

a-dub wrote: post #35

i wish the ui on those things was more visually appealing. between the cheap looking gloss finish on the display itself and the unextraordinary ui, it's just kinda blah. one can have a debate about to screen or not to screen or whether to use vfd displays or whatever and i get the importance of cost control but it should look good and it really doesn't. the graphic of the car looks like a cartoon.

Interesting take–– I feel the total opposite; I love the UI.

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

#69

Post by trebligdivad »

entropie wrote: post #33
kube-system wrote: post #13

> 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. I was really surprised to read this at the end of the article -- how could someone be this deep into a project of this depth and not realize this?! Not o…

> how could someone be this deep into a project of this depth and not realize this I think this is a software guy who occasionally dips into hardware things (to hunt bugs).

Yeh, it seems odd to have the cut off cables, the wiring information...and then to go and buy a loom rather than bodging a cable at that point.
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