[HN Gopher] Running Tesla Model 3's computer on my desk using pa...
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       Running Tesla Model 3's computer on my desk using parts from
       crashed cars
        
       Author : driesdep
       Score  : 143 points
       Date   : 2026-03-25 21:11 UTC (1 hours ago)
        
 (HTM) web link (bugs.xdavidhu.me)
 (TXT) w3m dump (bugs.xdavidhu.me)
        
       | owenthejumper wrote:
       | Could 'lb' be load balancer?!
        
         | trsohmers wrote:
         | It actually stands for "lizard brain"... it is (or at least
         | was) an Infineon Aurix control and monitoring microcontroller,
         | they may have changed to a newer one.
        
       | LikeBeans wrote:
       | 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 into the car that I found
       | on eBay. I velcro'd the controller under the dashboard. It works
       | pretty well. I towed my small camper several times with it last
       | year with no issues. Yay! However my little project is nothing
       | compared to this post. Love people hacking away. So cool.
        
         | ferongr wrote:
         | >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).
        
           | AlotOfReading wrote:
           | 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.
        
         | silisili wrote:
         | > But then I needed to find a brake controller that can work
         | with the higher voltage (14.4v vs the normal 12v)
         | 
         | Not understanding this sentence. Most running ICE vehicles
         | product closer to that 14.4 than 12v. I think a standard
         | controller would have worked fine?
        
           | serf wrote:
           | you're correct. a '12v ICE' alternator generates up to
           | 14.8-15.2v. Most automotive stuff can operate between
           | 9ish-16ish-v , of course totally depending on the product.
           | 
           | of course this is just a modern interpretation. older stuff
           | runs at 6v and some weirdo offbeat cars have a 24v/48v rail
           | sitting around somewhere. Cop cars often had alternators that
           | put out weird voltage ranges for certain equipment, or dual
           | 12v for high amperage output.
        
             | londons_explore wrote:
             | Whilst cranking, an ICE car will drop to around 6 volts
             | (then maximum power is extracted according to thevenim's
             | theorem).
             | 
             | That means all computers etc will work at 6v.
        
               | toast0 wrote:
               | > Whilst cranking, an ICE car will drop to around 6 volts
               | (then maximum power is extracted according to thevenim's
               | theorem).
               | 
               | > That means all computers etc will work at 6v.
               | 
               | Not necessarily all of them. Plenty of stuff will drop
               | out while cranking; hopefully not the computers that run
               | the fuel injection and ignition, though.
        
               | bluGill wrote:
               | The specs say no less than 6volts. In the real world when
               | the temperature drops down to -70F or colder and
               | batteries get old the voltage goes well below that: deal
               | with it.
        
           | LikeBeans wrote:
           | You are probably right. Surprisingly the first controller I
           | tried didn't work. I assumed the voltage was too high since
           | it worked in my other (much older) car. I found a reference
           | online of people that tried a particular brand/model and
           | that's what I went for. Thankfully my car isn't the model
           | with the internal 18v battery.
        
       | anigbrowl wrote:
       | I have no wheels and I must drift
        
       | MengerSponge wrote:
       | Fun linguistic quirk: Americans tend to call it a "wiring
       | harness", whereas Brits prefer "loom"
        
         | Dan_- wrote:
         | So what do you call the tubing around the wire bundle? That's
         | what we call "loom".
        
       | girvo wrote:
       | It's funny to hear LVDS be described as an "automotive" cable
       | when all of my run-ins with it are for connecting laptop displays
       | to their main-boards! (though that has a very different connector
       | on it, and its a very general term for the signalling protocol
       | from what I remember)
        
         | inamberclad wrote:
         | SpaceWire is also just LVDS with an uber-minimal routing
         | protocol. It runs on a lot of satellites.
        
         | slfnflctd wrote:
         | Not saying there's anything wrong with your perspective (lots
         | of terms get in muddied waters, it's common and not a problem
         | if everyone is on the same page), but this is what I just found
         | on Wikipedia:
         | 
         | "Early on, the notebook computer and LCD vendors commonly used
         | the term LVDS instead of FPD-Link when referring to their
         | protocol, and the term LVDS has mistakenly become synonymous
         | with Flat Panel Display Link in the video-display engineering
         | vocabulary."
         | 
         | https://en.wikipedia.org/wiki/Low-voltage_differential_signa...
        
           | girvo wrote:
           | Yeah I saw that too which is why I posted my comment, it's
           | surprising to me :) LVDS for display cables was an
           | _incredibly_ term in that context. Even still is sometimes
           | despite them mostly being eDP (embedded-DisplayPort) now,
           | which is _quite_ incorrect hah
        
       | dogman1050 wrote:
       | I love that it has a standard RJ45 ethernet connector.
        
         | bombcar wrote:
         | I thought I saw an HDMI connector, but maybe I was wrong.
        
           | inventor7777 wrote:
           | Ha! Reading this comment made me curious, so I went back and
           | looked at the article and there does seem to be a full sized
           | HDMI connector. I wonder if it is enabled, or just for Tesla
           | internal testing?
        
         | wds wrote:
         | How many PoE adapters would it take to charge a Tesla?
        
       | kube-system wrote:
       | > 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 only because all cars (...er... all
       | _vehicles_ ) are wired this way, but also because the
       | documentation they were referencing has plenty of detail to show
       | this... there's even a whole picture of it:
       | https://service.tesla.com/docs/Model3/ServiceManual/2024/en-...
        
       | caycep wrote:
       | Granted, I think it would be valuable to look at all sorts of
       | automotive ECUs. I always wonder how the tuning industry does
       | their thing; I shudder to think they're just sitting there
       | flipping hex codes directly in running software...
        
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       (page generated 2026-03-25 23:00 UTC)