Originally posted by monocoque_nut
Im looking at implementing ieee 1355 instead. easy to interface with any protocol and a lot more resilient than CAN. [/quote
Thats a bit cutting edge for me! seriously though being at the forefront of new technology acceptance means you are the guinea pig who finds the glitches. Also there is not hardware off the shelf available.
Interesting though!
skov - 20/9/13 at 11:59 AM
I'm using CAN bus to control the instrument cluster on my Haynes.
I did plan to run it all over the car to control various things (lights, fuel pump, etc) but decided it was much quicker, easier, and cheaper to just
use separate wires for everything.
v8kid - 20/9/13 at 12:03 PM
quote:
Originally posted by RickRick
can't see the benefit on a kitcar, i think i've only got 6 or 7 wires running to the back of the car, and there all thin low current as all the lights on the back are LED's. same ish to the front, all the others are in one loom at the dash however on a boat with lots of cables maybe it would be an advantage, but probably only if there are a few groups of electric things close together or you end up running lots of wires out from each terminal anyway
Oh there are lots of circuits on a largish boat! I'm not kidding about the 20km of cable. Winches (2 masts, 5 sails, it all adds up), generators, radar, sonar, navigation, radio (all times 2 for safety) and then there is the domestic stuff for 5 cabins and associated galleys. On top of that there are 24v citcuits, 110v and 240v circuits. not to mention lighting and computers (5).
On a locost the advantage is that all the switches, instruments and lights only need a power feed and a signal pair. I think most professional racing and endurance cars are CAN?
I'm tyring to find out if it is simpler and easier to use.
Cheers!
v8kid - 20/9/13 at 12:04 PM
quote:
Originally posted by skov
I'm using CAN bus to control the instrument cluster on my Haynes.
I did plan to run it all over the car to control various things (lights, fuel pump, etc) but decided it was much quicker, easier, and cheaper to just use separate wires for everything.
What hardware did you use?
v8kid - 20/9/13 at 12:12 PM
quote:
Originally posted by britishtrident
CAN Bus causes all sort of niggling problems on tin tops, steer clear.
Fair enough but on old cars all sorts of things cause problems.
I'm not sure its correct to say that CAN bus is any more unreliable than other things. I mean rubber bushes fail but thats not a reason to replace them with metal bearings.
It is a pain to trace CAN faults but surely thats because most people are unfamiliar with the technology and dont have the appropriate diagnostic tools. Now its easy and cheap to look on the canbus - eg Torque and other apps.
Cheers!
iank - 20/9/13 at 12:13 PM
quote:
Originally posted by v8kid
quote:
Originally posted by monocoque_nut
Im looking at implementing ieee 1355 instead. easy to interface with any protocol and a lot more resilient than CAN. [/quote
Thats a bit cutting edge for me! seriously though being at the forefront of new technology acceptance means you are the guinea pig who finds the glitches. Also there is not hardware off the shelf available.
Interesting though!
Not really cutting edge, it's just a standard written around the concepts first used by the transputer in the late 80's.
Though CAN (and LIN) are hardware tolerant to the nasty electrical environment in the engine bay and I suspect you'd need to use TS-FO optical for the physical layer of 1355 to get that level of reliability. Not worth the trouble unless you were very keen.
I'm with MikeRJ, the levels of testing and design processes around designing software for automotive are way above home project level (I design and build embedded software inside safety critical products and our testing runs to many months of engineer time even using specialised test equipment to speed things up).
v8kid - 20/9/13 at 12:15 PMquote:
Originally posted by MikeRJ
quote:
Originally posted by wylliezx9r
quote:
Originally posted by MikeRJ
Seems like an excellent way of building in a single point failure that would disable nearly all of the electrics.
Umm not exactly! All modern cars use CAN !It has built in redundancy - how much depends on the design of the system.
I'm well aware of the use of CAN and it's advantages, but I'm talking about the suggestion of using an Arduino rather than trying to adapt the system from a production car.
Yes I think you both have put your fingers on the problem. Although it is possible the hardware needs to be properly engineered and reliable.
Surely there must be adaptors out there? After all CAN is used in loads of places surelt each one id not developed fron scratch?
Cheers!
skov - 20/9/13 at 12:55 PMquote:
Originally posted by v8kid
quote:
Originally posted by skov
I'm using CAN bus to control the instrument cluster on my Haynes.
I did plan to run it all over the car to control various things (lights, fuel pump, etc) but decided it was much quicker, easier, and cheaper to just use separate wires for everything.
What hardware did you use?
Probably doesn't help you much, but I just used some little boxes I happened to have lying around (the three grey ones on the right).
I've got them monitoring various signals from the car and generating CAN messages to drive the cluster from a BMW Mini.
They were originally designed for a different purpose, but a quick re-write of the software fixed that
I can't think of any generic off the shelf modules off the top of my head, but surely someone must do something??
[Edited on 20/9/13 by skov]
stevio73 - 20/9/13 at 02:27 PMWhy complicate? CAN for me very quickly turns into CAN'T. (Or is that because I'm a dinosaur?)
Volvorsport - 20/9/13 at 04:30 PMany euro 3 bus or truck onwards is CANbus , and they all try to use there own language ...
but the signals are dead quick... and i bet you could use the modules....
we have a guy at work on contract whos apparently an expert with canbus/mapping - he does the MGs for BTCC..
ill have a word or pass on his number if its worth it ....
mad4x4 - 20/9/13 at 04:37 PMquote:
Originally posted by v8kid
quote:
Originally posted by RickRick
can't see the benefit on a kitcar, i think i've only got 6 or 7 wires running to the back of the car, and there all thin low current as all the lights on the back are LED's. same ish to the front, all the others are in one loom at the dash however on a boat with lots of cables maybe it would be an advantage, but probably only if there are a few groups of electric things close together or you end up running lots of wires out from each terminal anyway
Oh there are lots of circuits on a largish boat! I'm not kidding about the 20km of cable. Winches (2 masts, 5 sails, it all adds up), generators, radar, sonar, navigation, radio (all times 2 for safety) and then there is the domestic stuff for 5 cabins and associated galleys. On top of that there are 24v citcuits, 110v and 240v circuits. not to mention lighting and computers (5).
On a locost the advantage is that all the switches, instruments and lights only need a power feed and a signal pair. I think most professional racing and endurance cars are CAN?
I'm tyring to find out if it is simpler and easier to use.
Cheers!
We do control systems for work and would use EtherCat on a tcp/ip network using something like Beckhoff hard ware,
Texan - 22/9/13 at 08:52 PMAs we use newer & newer donor vehicles I see Can Bus becoming more of a reality for all of us PLUS I see it as a solution to all the problematic cut down wiring harnesses so I'm definitely interested in learning more about them and seeing any aftermarket alternatives.
Even without newer donors I see this as a way to lighten & simplify, things Colin would definitely have appreciated.
Unless I'm totally misunderstanding exactly how it works, which wouldn't surprise me, it doesn't seem to be all that difficult a concept.
v8kid - 23/9/13 at 07:39 AMquote:
Originally posted by mad4x4
quote:
Originally posted by v8kid
quote:
Originally posted by RickRick
can't see the benefit on a kitcar, i think i've only got 6 or 7 wires running to the back of the car, and there all thin low current as all the lights on the back are LED's. same ish to the front, all the others are in one loom at the dash however on a boat with lots of cables maybe it would be an advantage, but probably only if there are a few groups of electric things close together or you end up running lots of wires out from each terminal anyway
Oh there are lots of circuits on a largish boat! I'm not kidding about the 20km of cable. Winches (2 masts, 5 sails, it all adds up), generators, radar, sonar, navigation, radio (all times 2 for safety) and then there is the domestic stuff for 5 cabins and associated galleys. On top of that there are 24v citcuits, 110v and 240v circuits. not to mention lighting and computers (5).
On a locost the advantage is that all the switches, instruments and lights only need a power feed and a signal pair. I think most professional racing and endurance cars are CAN?
I'm tyring to find out if it is simpler and easier to use.
Cheers!
We do control systems for work and would use EtherCat on a tcp/ip network using something like Beckhoff hard ware,
We use Beckhoff twincat as well but it is quite susceptible to interference. The twincat controls gas flow on a box coater and when we turn up the plasma it slows right down as the error correction kicks in. ( I presume that's why!).
Hence the interest in CAN bus as it is inherently more immune to interference than ethernet.
Cheers!
v8kid - 23/9/13 at 07:47 AMquote:
Originally posted by Texan
As we use newer & newer donor vehicles I see Can Bus becoming more of a reality for all of us PLUS I see it as a solution to all the problematic cut down wiring harnesses so I'm definitely interested in learning more about them and seeing any aftermarket alternatives.
Even without newer donors I see this as a way to lighten & simplify, things Colin would definitely have appreciated.
Unless I'm totally misunderstanding exactly how it works, which wouldn't surprise me, it doesn't seem to be all that difficult a concept.
You are right the concept is quite simple its the implementation that gets complicated! There are so many interacting systems on a saloon that it is difficult keeping track of them all - particularly safety systems such as brakes, air bags etc.
However for a locost, or a boat, these complications do not arise and provided robust cheap modules can be sourced it would be a winner. However so far I've found you can get cheap, reliable or easy to program choose any two.
Cheers!
Texan - 23/9/13 at 02:07 PMDoesn't each device on CanBus just use different "frequencies"?
I'd not think we get anywhere near limits of different frequencies on the typical car. As a matter of fact if we did then I don't think the auto manufacturers would be using it.