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Discussion Starter · #1 ·
I am an electrical system engineer with some 10 years experience around EV technology and I have watched with interest the growth of the EV sector around leisure vehicles and classis car conversation. I can see the main modules being used and indeed the use of OEM donor parts such as Tesla donor parts but I wonder if there is a bit of a technology gap around the area of CAN and system integration?
My last EV project was the control system for the Electric Touring Car series, which had quite a large budget and a team of about 3 full time people, one of which was a controls person just doing controls and CAN database work.
I am really interested in how then home DIY-er is dealing with integration of CAN based modules, PWM and LIN
controllers or modules.
Does everything just plug and play or is it all just hard wired?
Has anybody got into functional safety?
I am considering converting a classis car to EV but I know it would be really hard to do if the OEM methods were followed.
What is happening in the shed and garages around the world?
 

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I'm the biggest rat here, as many will attest, by way of introduction.

So, you'll be placing cheese for us to find, then, since you are "considering" vs doing?

Feel free to pull up your sleeves and see if you can figure out how to get a CAN power steering pump under full control, like the one out of a 2004 Volvo as your first slab of Jarlsberg.
 

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You're probably have better luck on the Openinverter forums, they're quite a bit more technical (though more European).

CAN integration in my experience has been handled three ways:

1 - Someone highly knowledgeable does it all themselves for their car, and then never documents a damned thing and moves on.

2 - Some company pays its engineers to pour over it and write it out, or, to hijack an incomplete open source project and finish it up and make it all proprietary, sells you a finished solution.

3 - The community reverse engineers the CAN signals and builds things based on them.

Obviously #2 is the simplest, just throw money at them, but the most limited, since you get what they gave you and what was worth their development cost, and that's that.

Obviously #1 is the hardest, do everything yourself.

Obviously #3 is the best, but, even then, as most open source projects, there's 80% solutions for many things, or a "just barely got it working and then moved on" solutions that could really only be implemented or understood by the person who made them or others at their skill level. There's very little at a moderate or novice level that's actually approachable.
 

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I'll agree with Matt. The potential for reuse of OEM components is barely being scratched by goodies such as the Thunderstruck Motors VCU. I've spent that last couple of years putting late model high capacity LEAF battery packs into early cars, but remained largely in the dark because the gateway "man in the middle" module used to get past Nissan's unnecessary obstacles to this upgrade remained a hexadecimal mystery during remote reprogramming sessions by a faraway hacker. Tesla upgrade modules from Ingenext follow the same business model- you buy some hardware and then hire a remote programmer to make it work. I received some spendy training by a retired OEM EV engineer who simply responded to all our hobby-level conversion techniques with "This would never pass in a Program." Then he tried to get us to install thousands of $ worth of HV leak detection circuitry on any system greater than 60V, which kills the finances of a conversion. Following the DIY hack of a fellow hobbyist is always difficult and often ends in frustration, but is usually more practical...
 

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Discussion Starter · #5 ·
Hi,

The reason I am considering doing an hobby EV project and not actually doing one yet is that I consider using OEM components a real non-starter unless there is already a community of engineers who have already reverse engineered a few chosen components. This is really why I am here, to find out how far this path has gone.
I work with CAN on a daily bases (or have done in the past) with all industry standard tools at my disposal. I have also been a component engineer with LandRover Jaguar so have a deep understand of now a module works on a diagnostic and CAN level.
This is not a simple topic, and as a real hobbist I am not sure I could do it in my garage.

CAN itself isn't a protocol, like OBD, so different manufacturers do things in different ways. And there is a bit of 'mopping-up' done with CAN massages - bit-stuffing. Where unrelated data is added into free space in unrelated massages.

Certainly on JLR platforms modules are told what vehicle they sit on via a 'CCS' file. This is broadcast via CAN to each module at power on to instruct the module what Cal to use, Engine type/trans type/ trim level/ wheel size/ etc. Although once learnt, the module does not need to see this massage on every power up, a module can certainly lose this (loss of perm power etc). If the module can not be updated it is just a paperweight. I am sure JLR is not the only OEM to use similar techniques.

Functional safety - a bit later on vehicle architectures but certainly to be considered when selecting components. Functional safety is a technique where modules can check the rest of the system is working correctly by monitoring CAN data. A module separated from the rest of the architecture and fed with the correct CAN massages via a CAN injection tool may still stop functioning as it has detected, via functional safety, that the rest of the architecture is not functioning correctly.

I hope this isn't too negative. And on the plus side, I work on new vehicle development so the technology I work with is yet to be in car showrooms. Components in the hobbist's parts bit will be much earlier than this so easier to work with.

I am new to the topic of hobbist EV development, so I have a lot to learn. For me, with what I have seen so far, it seems that component selection is based on the ability to control the electronic or use systems that are stand-alone or indeed still offer a base level of functionality even in fault mode.
 
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