Wiring genius: 48v power + data CAN bus

[GuyV]

But

Power and data signals travel on different circuits

Or is someone seriously suggesting eg the speakers are operated only by data packers

this seems misleading or confused

Just Google POE

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[Challeco]

Oh. great. So, if something happens to a section of the wiring harness, the whole thing needs replaced?! So much for DIY laws.

 

[Tiberius]

Oh. great. So, if something happens to a section of the wiring harness, the whole thing needs replaced?! So much for DIY laws.

Just means the repair needs different skills (mostly computing), the use of distributed controllers has been going on for years and Tesla took it to the next logical step long before the Cybertruck arrived.
Great example is the headlight in a modern Tesla like a Model 3, it seven individually addressable light components in there, without each light needing a set of wires. Changing the headlight requires a reboot
Just means the bar for compatibility is higher, that hasn't stopped plenty of alternatives showing up.

 

[2DVS4U]

So, rap music might cause my steering to malfunction in the daisy chain and the suspension might cause my cybertruck to bounce off the road. haha

Good thing I don't listen to that kind of music!

 

[cvalue13]

Just Google POE

i guess I was speaking/asking more of the devices that require more significant power, like the stereo speakers

but maybe this is also all sorted

On the other hand, the CT still has 12v used and available

 

[ricinro]

Yep.

The daisy chained bus architecture was actually more important at reducing wiring than the 48V upgrade.

This has been happening for a while in cars as microcontroller costs fall, it becomes more cost effective to distribute controllers in the vehicle rather than long cables, unlike the analog days.

There's still 12V on the vehicle, all the CPU/GPU, displays etc will need it, plus the USB-C PD outlets etc.

I am behind the times regarding processors etc. but I recall the voltage for computer chips being ~3 volts, same for LEDs etc. I guess there is always some DC-DC converter involved with any supply voltage.
I am curious about low voltage DC home standards as well because I really have a dislike of all the wall warts (120AC-12vdc) and built in power supplies. As we really mostly use computers for most things around the house having DC complementing the 120/240 circuits would make sense. Add data communication and it gets cool.

 

[ricinro]

I am behind the times regarding processors etc. but I recall the voltage for computer chips being ~3 volts, same for LEDs etc. I guess there is always some DC-DC converter involved with any supply voltage.
I am curious about low voltage DC home standards as well because I really have a dislike of all the wall warts (120AC-12vdc) and built in power supplies. As we really mostly use computers for most things around the house having DC complementing the 120/240 circuits would make sense. Add data communication and it gets cool.

 

[Knucklehead]

Adding a subwoofer may be very difficult, and maybe impossible for the average subwoofer fan.

 

[Kahpernicus]

Oh. great. So, if something happens to a section of the wiring harness, the whole thing needs replaced?! So much for DIY laws.

When a child device in a network fails, the entire network doesn't go down.

 

[JBee]

Oh. great. So, if something happens to a section of the wiring harness, the whole thing needs replaced?! So much for DIY laws.

Maybe you missed my post on page 1 about the ring bus topology.

Imagine a complete circle, and that is a cable connected to itself as a loop. Then add nodes to that same cable (like lights) all the way around.

Now what happens if you cut the circle cable in one spot between two nodes?

They all stay on because they are still all connected by the rest of the circle.

With a CAN type ring bus you can do exactly that, which means technically you have now got redundant wiring, and all you added is connecting the two ends of any cable you had to run through the vehicle anyway. In fact you can create multiple interconnections with the circuit having more redundant pathways.

This is the beauty of data over DC, you only need to make sure you have the cables connected in the right polarity and you are good to go.

 

[Crissa]

Oh. great. So, if something happens to a section of the wiring harness, the whole thing needs replaced?! So much for DIY laws.

It actually makes repair easier. You just fix the one cable or unit, instead of a whole harness. The cables are common instead of specific to each peripheral.

A mesh wifi system solved that problem for me.

But if you want to keep everything hardwired, look up "Daisy chain ethernet" to see how it can be done and why you probably don't want to do it for a personal residence. It requires an ethernet switch at every daisy chain point. Here is one article: https://www.techrepublic.com/article/only-novices-daisy-chain-switches/

...that's how my house is wired. There's a switch in the bedroom, one in the media cabinet, and then the few off the router.

If I want more than one device in the room, it gets a switch. Bedroom has some weird echoes, so it gets a switch. Office doesn't, but I ran two data wires to it anyway. One goes up the arm that holds the monitor. The media cabinet is an old brick fireplace so it gets a switch.

Means I only had to run one data line to each room.

-Crissa

 

[wtibbit]

It actually makes repair easier. You just fix the one cable or unit, instead of a whole harness. The cables are common instead of specific to each peripheral.


...that's how my house is wired. There's a switch in the bedroom, one in the media cabinet, and then the few off the router.

If I want more than one device in the room, it gets a switch. Bedroom has some weird echoes, so it gets a switch. Office doesn't, but I ran two data wires to it anyway. One goes up the arm that holds the monitor. The media cabinet is an old brick fireplace so it gets a switch.

Means I only had to run one data line to each room.

-Crissa

Crissa, do you have any of your switches wired like this:?: Router->Switch->Switch->Device (where both switches could have one or more end devices connected.) The daisy chain aspect is that the second switch is not connected directly to the router.

I'm just trying to visualize your wiring better. My mesh WiFi system was a little pricey and I'm wondering it I could have done it with a few more E-net cables and cheap switches.

 

[CYBRSMTH]

This is genius. Hopefully it trickles down to all of their other vehicles. Not only is it more efficient, but it’s cost cutting.

 

[Nabilriaz69]

You know how cars have huge wiring harnesses?

That's because each component needs its own set of wires, connected to the central ECUs, in order to function.

Every speaker, every switch, every sensor, every actuator, every button.

Tesla threw out that entire system for Cybertruck.

Instead, they're running gigabit ethernet cabling with a 48v power + data CAN bus to every component— all on the same cable.

Instead of running one wiring harness to the driver door speaker, and another to the driver's door window motor, they can daisy-chain them together on the same self-contained cable interface. Your computer could connect to your door handle using the *same* wire that's already been through your speaker, window, ambient lights, and steering wheel.

Each of those devices/components listen to the continuous stream of data for a command relevant to its operation.

By doing this,Tesla was able to reduce the total wiring in the Cybertruck by 77%, using 1/2 the copper.

cybertruckguy

This is very misleading post someone imagination , 48v system allow smaller diameter cable , which results less wait , Tesla used 48 v for steer by wire also because that steering motors needs lot of power

 

[Petertsai]

You know how cars have huge wiring harnesses?

That's because each component needs its own set of wires, connected to the central ECUs, in order to function.

Every speaker, every switch, every sensor, every actuator, every button.

Tesla threw out that entire system for Cybertruck.

Instead, they're running gigabit ethernet cabling with a 48v power + data CAN bus to every component— all on the same cable.

Instead of running one wiring harness to the driver door speaker, and another to the driver's door window motor, they can daisy-chain them together on the same self-contained cable interface. Your computer could connect to your door handle using the *same* wire that's already been through your speaker, window, ambient lights, and steering wheel.

Each of those devices/components listen to the continuous stream of data for a command relevant to its operation.

By doing this,Tesla was able to reduce the total wiring in the Cybertruck by 77%, using 1/2 the copper.

cybertruckguy

I believe that is called power over internet. There is limited power available. I believe the current is 1 amp unless Tesla changed wire size And connectors.

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