Single wire wiring loom?

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tygertung, Mar 22, 12:23am
What if you just had one wire with 12v DC running down it, and also a high frequency AC data signal?

The wire could go to all the parts of the car such as lights, windscreen wipers etc., and the data signal would tell the little control module in all the componants such as lights and wiper motors etc. to turn on. This would make the wiring loom much simpler.

The central computer could interrogate each module and that way you could tell what was and wasn't working?

Do you think this scheme would work? What would be the advantages and disadvantages?

tweake, Mar 22, 12:30am
isn't that basically the existing canbus?

the problem with single wire is getting good quality signals down it without it being screwed over by interference.

poppy62, Mar 22, 12:31am
Save the wiring and go Bluetooth.

tygertung, Mar 22, 12:33am
I guess you could have a single shielded wire.

tweake, Mar 22, 12:49am
forget bluetooth, to unreliable.
know some guys who had bluetooth trailer controllers. not much fun when the brakes do not work.

tweake, Mar 22, 12:51am
yes. that would work.
however still the issue with the wiring from the module/relay to the device.
unless you put the module on every device and that can get problematic.

tygertung, Mar 22, 1:50am
I was thinking that each device would have a module on it, like each tail light cluster would have a wee microcontroller module on it, and the main computer would send a signal down the data/power bus saying "turn on left indicator" and the microcontroller would do so.

androth2, Mar 22, 2:16am
The data wire would need a return wire and there will still need to be a 12 volt power lead to each unit

clark20, Mar 22, 2:21am
Already happening

tygertung, Mar 22, 3:47am
Surely data can travel in both directions, it would just need to be clocked up. DC and AC can travel in the same wire, so you can just have one universal wire.

loud_37, Mar 22, 4:43am
Isn't this how most modern cars are wired today?

intrade, Mar 22, 6:43am
there was a single wire bus i cant recall if its k line of the top of my head canbus is twisted pair to offset interfearing can high and can low 2.5 volt modulated in either direction, most bus is fiber-optics as found in bmw etc
what poster 1 proposes is done and dusted already.
and now we have doors shutting down engine with faults,,

https://automotive.softing.com/standards/bus-systems.html

intrade, Mar 22, 6:56am
toyota have a 7 volt system in them 90s corollas= why they dont crap them self as fast on voltage drop as 5 volts with 2.5 volt signals
dont worry modern toyota have the 5 volt one so crap them selfs just like anything else its only the 4a-fe etc who are built rugged.

budgel, Mar 22, 7:09am
The BMW system is great while it is working. One fault is the beginning of the nightmare!

intrade, Mar 22, 7:18am
that goes for all and everything. if i have to die then i want to be the one who caused my death and not some crap from this guy who should be locked up in psycho ward since years.
https://abcnews.go.com/Business/tesla-autopilot-steered-driver-barrier-fatal-crash-ntsb/story?id=68936725

tygertung, Mar 22, 9:28am
I don't think that a door fault should shut down the engine, it should just come up with a message saying you have a dud door module.

shakespeare6, Mar 22, 10:20pm
Op has missed the boat or pulling a leg. Cars have had canbus systems for years. Now days when cab upgrades are done to yarders in the bush they are all converted to Canbus. Harvester heads on excavators have Canbus modules in the head now instead of running control looms. Tethered Harvesters are using Canbus over radio links to control the winch machine. I got involved with these projects years ago.

tygertung, Mar 22, 11:49pm
It was just an idea I came up with. I had no intention of doing anything with it.

intrade, Mar 23, 12:57am
2008 bmw toyota have this stuff now also. the more crap the more expensive it will become.
https://www.youtube.com/watch?v=B7gggowzPSE

intrade, Mar 23, 1:16am
my coffee machine has a canbus also i read somwhere.
delonghi fully automatic. my first one was seaco superautomatica in the late 1990s when they sold brow water on a hotplate as coffee in nz . I already had a fully automatic coffee machine back then.
my first one 480 swiss franks i got it before 911 i clearly remember as the jankes had lost it in transit. that was like 700$ nz
my new one was 380 about 600 bux and harvey sold it for 1200 doller few years after i got my one in the luggage from europe
my one dont has the milk thing. and it looks prices became more realistic now.
https://www.noelleeming.co.nz/shop/whiteware-kitchen-appliances/small-kitchen-appliances/coffee-machines-and-grinders/delonghi-ecam23460s-fully-automatic-coffee-machine/prod129536.html?gclsrc=aw.ds&&gclid=EAIaIQobChMI4KCblt7C7wIV2NxMAh264AI8EAQYAiABEgKviPD_BwE&gclsrc=aw.ds

onl_148, Mar 23, 1:19am
The easy part, technically, is the single bus with basic modules to do something when addressed to do it. the tricky part is to make it bullet proof / safeguards etc etc. you do not want a faulty boot opening module to drag down the bus or effect the accelerator pedal module ?

car__parts, Mar 23, 1:34am
It would worry me,Carputers are packed with up to 100 million lines of computer code, more than in some jet fighters.

Even basic vehicles have at least 30 of these microprocessor-controlled devices, known as electronic control units, and some luxury cars have as many as 100.

tygertung, Mar 23, 1:59am
I would think that the accelerator could easily just have a good old cable, no need for a module for that. Same for the boot. The brakes can just act directly on a hydraulic cylinder.

Cables should be used wherever possible to reduce excess modules.

bigfatmat1, Mar 23, 4:02am
No its a not a very good idea to much noise in a car to have data traveling over a power cable. Would also need a negative so would be two cables. We have good systems in vehicles now various types of data transmission used on cars. Lin bus is a single data wire but there will be a power and earth. Like audi wiper motors.

tygertung, Mar 23, 4:09am
You can use the car body as an earth. Use a shielded cable, and use a high enough voltage for the data signal so that noise isn't an issue.