It’s a Nerd Thing – and a Geeks World After All.


It’s not my fault really. Automotive technology has simply evolved to be more….technical.

I guess when we started EVTV I thought we needed to fit into the custom car “guys in garage” motif. After all, we were computer geeks. But I found it interesting in a couple of recent informal surveys of our viewership to learn that almost ALL of them are computer or information technology/networking people as well. Indeed, I would guess at this point that 90% of our viewership is/are/was employed in the computer/internet ecosphere.

We do hear from traditional “car guys” who would like to make the trip to convert to electric drive. And we would like for them to. They profess mechanical ability and fabrication skills, but little in the way of electrical skills. Indeed a lot of the hot rod crowd have somebody else do their basic vehicle lights and horn wiring.

I’m sympathetic. And indeed it is an acquirable skill. When converting a classic, as we so often do, the “electronics” is really pretty basic and indeed you will find the batteries and motor and controller and pedal much easier to work out than the typical light and turn signal circuit (which drive me crazy by the way).

But more modern cars offer a different challenge. And the challenge is not so much to get it to roll, as it is to interface with the vehicle electronics to gain access to all the features that came with the car. And so in the past year or so, really dating back to the Escalade build, we have been more involved in that.

I’m very pleased with the Generalized Electric Vehicle Control Unit. It’s a remarkable device that I think will make most of all of this much easier. But it has its frustrations. We are just now sending out the next flight of 30 units that have been ordered and they are pretty much spoken for. So I have 100 of the 5.2 version in work as I write. I entered FOUR different orders and waited a day or two on each, just to get the right size of the little tiny nylon screws and nuts I needed to properly mount the new ConnectOne wireless board to our GEVCU board. There’s no fun in this at all. At the last minute, I noticed the pinout placard indicated version 4.00. And so those had to be reordered. And so it goes.

Are these major issues? No. But God is in the details. The difference between a confusing mess in a box with no instructions and no clue how to effectively use it, and a useful product you can use as a tool, is usually just a handful of small details. I know I order a lot of things from China and off of eBay. They usually take several weeks to arrive. And too often, I can’t even tell what it is or why I ordered it. And nothing to indicate any of that in the package.

And so an increasing amount of our time and effort goes to small electronic devices to use with your electric car. And less and less is spent on shiny motors and new batteries and the things that make cars go.

I think most of the computer geeks will be pretty sympathetic to that. In fact, I think some will actually get into to it in a pretty big way. After years of very limited interest in “hot rods” and all that implies, suddenly, we have cars they can understand. And cars they can change. And modify. And do computer guy things with.

That’s a new thing.

Speaking of things, in this episode we attempt to chase down an intermittent and fairly catastrophic failure with the electric 1973 Volkswagen Thing that simply leaves us rolling to the curb. But it has been hard to reproduce. I’ve never met a connector I admired, and I think that’s the case here as well.

We basically rewired the GEVCU device entirely into the car. It had been through several prototypes and a few too many pins had been inserted and removed from the main connector. I made a connection diagram for Jesse to use and promised to share in the blog. Here it is.


Accompanying me in this issue is Mr. Damien Maguire of Ireland. He introduces a new BMW 840CI build that should be fascinating to follow. More so as Maguire has built the power electronics to drive the Siemens motor, and indeed developed an Arduino based device to control the automatic transmission as well.

I was very pleased with Paulo Alameida’s contribution last week showing how to drive a Mazda RX-8 instrument cluster with an Arduino Due and a CAN shield. In most of Europe, you’re not even ALLOWED to have a check engine light or other lights showing on your dash panel after you convert to electric. But in any event, ultimately we want all of our dashboard to work correctly. And CAN based instrument clusters actually do lend themselves to this if we can decode the messages used and provide them.

That’s all pretty doable. But not always easy. I think it will be a bit of a puzzle that many of our computer geek viewership will enjoy – if they have the tools.

We’re working on it.

Ed Clausen and Collin Kidder and I collaborated over a year ago on a CAN shield add on for the Arduino Due that would allow you to communicate with a CAN system using inexpensive hardware. Unfortunately, in some sort of communication mangle between Ed and a U.S. based assembly house, we wound up with 100 totally useless CAN shields with the connectors on the board upside down, and no way to plug it IN to an Arduino Due. The connectors have so many pins, it is essentially impossible to desolder and remove them without damaging any of the board lands, and so I have $6000 worth of totally useless CAN boards sitting in a box. Occasionally, I try to recover one and USUALLLY get ONE of the CAN channels working. But they are not salable.

We got off on GEVCU development and as I have described, this has had its own frustrations. But we are gradually winning and we continue to improve and refine with each iteration.

As I said, I’m extremely pleased with the GEVCU. It’s a powerful device with endless flexibility. But I am aware it is a touch expensive at $595. I don’t see a clear path to making that better. Everytime we shave a bit off the cost, we also add something to the mix, and so the costs actually creep up.

In any event, the CAN gestaldt is more about lots of LITTLE processors than one big central one. So I’ve worked hard to “get over it” on the CAN shield. Collin’s DUE_CAN library is actually a marvel and he recently was persuaded to add callback interrupts to it. You can literally act on receipt of a filtered CAN message now. More, you can have a number of acts that are only triggered on DIFFERENT filtered CAN messages now. It’s actually quite startling. But because of our real time OS like tickhandler in GEVCU, it doesn’t come into play. But for other purposes, it is enormously powerful.

So I took the CAN shield to China, and I’m pleased to report it should arrive this week – quantity 50 at least.


This device, which we’ll certainly price under $100, does a couple of things. First, Arduino Due has rather left out any means of persistent storage. If you want to retain some configuration variables or options, there’s really no place to put them so they will be available the next time you power up. It IS probably possible to use the provided flash memory for this, but if you recompile the software to the board, you lose all those. So we’ve added an electrically eraseable programmable memory or EEPROM chip to this add-on board for Arduino Due.

The Due multiprocessor actually has circuitry built into it to control TWO CAN bus channels. But the Arduino guys did not think it sufficiently important to put the necessary transceiver support chips on the Arduino board. Ergo this shield.
CAN networks require an impedance termination on each end – 120 ohms. This is normally provided by a couple of devices on the network, and in tapping in, you usually don’t have to worry about it. But in the event you are using the shield to connect to ONE device for example, we have provided terminations on the board. They are not connected. To connect them, a couple of closely spaced lands are provided. You simply bridge them with a dab of solder to connect them and activate the termination. I might also mention that we provide those on the GEVCU board as well.

We used RJ-45 female connectors on the board to offer easy connections to these two CAN channels. RJ-45 connectors are a small eight pin connector used on CAT5 and CAT6 ethernet networks. They are inexpensive and easy to connect. I’ve provided a diagram showing the pinout and indeed how to wire it up to a J1962 OBDII connector if anyone is interested.


And so with a $35 Arduino Due board, and this inexpensive CAN board, along with Collin’s DUE_CAN library , you can do a lot of damage to a modern automobile.

But wait, there’s more. We are wanting to do quite a bit of reverse engineering of CAN signals here at EVTV. I persuaded Paulo to do a similar board, but with slightly different connections, and most importantly, a microSD card slot.



These little cards are a marvel of the age. They are very fast (30Mbps), of huge storage now with 128GB cards going for a little over $100 (click on card image to go to Amazon). And they are 0.6 x 0.4 inches in size weighing 0.3 ounce. That’s basically about the size of a fingernail holding 128 gigabytes of data at LESS than a buck a gigabyte. Can you spell 1983? Can you REMEMBER 1983? Future rush. 61wBnz8JK-L._SL1500_

For those of you who CAN’T remember, those were the days where 1 MEGABYTE of hard drive storage went for about $1000 and was eight inches in diameter. Five of them on a spindle gave you 5MB of hard drive for $5000 in a device the size of a portable sewing machine. This little card is over 25 THOUSAND times as much storage, for $106. That $5000 has shrunk to a bit over NINETEEN CENTS ($0.1953 actually).

I suppose you could go the other way and say that the 128GB would have cost $128 million in 1983. Of course it would have also been 1/1000th the speed – and the size of a 3-bay car wash.

So understand I’m a little agog at these little cards. We have them in the GoPro video cameras and I consider it basically UNLIMITED video storage at 1920×1080 and 30 fps. It isn’t I guess. But since the battery runs out before the storage space does, it is for our purposes.

In any event, I wouldn’t advocate a 128GB card in this shield. 2GB would be overkill. They go for $5.25 cents.

So why the memory storage? Kvaser makes a CAN bus device called the Leaf Memorator. It’s over $1000 and lets you record about a gigabyte of CAN traffic. That’s really the only difference between it and the Leaf Lite at $350. Here, with this CAN shield, a $35 Arduino Due board and a $5 microSD card, you actually have TWO CAN channels and can record both – replacing a $1000 device that works almost as well.

This goes quite beyond simply reverse engineering CAN traffic. Our inverters, both the DMOC645 and the UQM Powerphase 100, report inverter temperature, battery voltage, battery current, motor temperature, and of course torque. It would be TRIVIAL, and I mean truly trivial, to write a program to filter for those messages and record that data for all your drives. You could then graph your torque, basically your accelerations and decelerations, plotted against ampere hours or battery voltage for example. That opens the door to a huge horizon of real world battery tests. And if you sprang for a 32 GB card, you could probably record ALL your drives for a year.

This version features some rather different connections. I asked Paulo for a DB-9 connector because it is rather inexpensive for us to add a DB-9 to J1962 Type A connector cable. This allows you to plug easily into the OBDII connector on your car. We’ll include that cable with the shield but here is a diagram of the pinout.


Note that it picks up 12v and chassis ground from the OBDII connector. This is actually routed to the 12vin on the Arduino and so you can power the whole thing from the OBDII.

There are certainly times you DON’T want to use OBDII to connect to a CANbus. He’s included some screw terminals for the 12v power and ground, and the CAN HI and CAN LO signals so you can wire it as you like.

Finally, it also provides the EEPROM chip missing from the Arduino.

There is actually MUCH more to come. In final testing at the Converte labs with Celso and Paulo is the JLD505. This is a modern replacement for our JLD404. This device will do accurate current measurements of your device in ampere hours and kilowatt hours, as well as pack voltage. Like a little mini-bms. But it will report it via THREE different interfaces, USB, Bluetooth wireless, and CAN. It will also have two control outputs so you can control relays based on voltage, current, ampere hours, kilowatt hours, etc. just like the JLD404. But more accurately and CAN enabled. No doubt we can add a function in software so it can trip relays on received CAN messages from other devices.

And finally, Ed Clausen is working on a full metal jacket BMS with temperature monitoring, up to four pack segment voltages, current, and more in a GEVCU like CAN package. No, it won’t top balance your batteries or bleed energy from them so as to have enough to start the fire.

So I see a future, not only of opening up modern cars to reuse their component parts for our builds, but in many cases converting modern cars to do our will electrically. And that is going to involve things like Paulo’s Mazda RX-8 instrument cluster, or Damien’s automatic transmission controller. And I just cannot change the fact that customized and modified automobiles of the future are really going to belong more to computer geeks and nerds than they do to the previous generation of hot rod builders.

But what I can do, and we are committing inordinate time and treasure at EVTV to do now, is try to build tools to make it easier for all to make the attempt and attack the problem. Tools with clear instructions and diagrams so you can actually USE them – even if you are not a EE but do have basic computer geek skills. And we are scribing that mission on all temple walls, tablets, and obelisks throughout the EVTV realm. Easy to use tools to demystify the proprietary CAN control of cars.

For good or ill, that probably means that EVTV is moving toward more technical presentation all the time. I fear this will narrow our viewership further, and leave a few behind.

There’s no help for it. We lost some to lead-acid batteries. We lost some to the incendiary BMS. And we are going to lose a few to the future. Eventually, we may get this down to three guys here at EVTV and six viewers. But they are going to be six really SMART viewers.

Or should I say, SmartED.

Jack Rickard

45 thoughts on “It’s a Nerd Thing – and a Geeks World After All.”

  1. Looking at the Thing wiring diagram, and aware of the hard work that’s gone into it, I became worried that it could be easily stolen (I live in New Jersey). Surely not a serious issue, and probably tons of ways to solve that problem. For example, I carry around a HID card just to get into my office building. Maybe a USB card reader can be connected to GEVCU?

    1. You’re talking about the car being easily stolen? The GEVCU has no concept of such things. If someone manages to get your keys and/or hotwire the ignition then it could be possible for them to take the car. Of course, it being an EV there are probably additional hoops to jump through such as flicking switches on the dash. This is certainly not insurmountable. So, yes, I suppose it’s possible to steal a custom electric car.

      Now, the question is, who is responsible for fixing this? Do we just ignore the possibility? In some places you can. I don’t tend to lock my cars at home since it just isn’t that big of an issue. I’ve never had a car stolen but I have had things stolen out of one. Or, should the security be in the car design itself? Maybe it’s hard to pop the locks and hard to get to the ignition wires. Maybe we just bank on the theory that a custom car is too suspect to sell intact and too specialized to be of much good at a chop shop? Certainly they wouldn’t know what to do with the batteries, motor, controller, etc. They could sell the normal car parts though.

      There is no reason that the GEVCU could not have some security added. There are lots of options. You could use bluetooth with your phone to unlock the vehicle when your phone is in range. You could use ZigBee. You could use RFID, key cards, secret Masonic hand shakes, or anything you wanted. Now, that leads to the question of whether it is worth it. Does anyone steal custom built electric cars? If so I’ve not heard of it being a big problem.

      But, if enough people want high security in GEVCU I’d do it.

      1. For theft protection, RFID might be the easiest but I’m not real keen on theft protection of a custom vehicle either. I’m not one of those people with a $4,000 vehicle with $8,000 of stereo equipment in it. I live in a rural area and the last time I had a problem with auto theft was when I spent 2 days in Chicago. They didn’t steel the car, just the tires. Now if only the lug nuts had rfid…..

  2. dont give up on us car guys just yet, Jack anyone who began working in the auto repair trade after ’96 has daily interactions with CAN. the only difference is if the technician gives a shit on how it actually works. the potential network you can customize, to your own needs/requirements in your specific build that GEVCU can provide is awesome. gonna try to keep up.

    mechanic/wanna be computer geek

  3. Jack, be not dismayed. Please do not abandon your original proclamation to gather 100,000 guys with garages to change the world. Your greatest talent is the uncanny ability to decipher the arcane and let the rest of us reap the benefits. I too have a modestly geeky history, however the acronyms and arrogance of geeks provides an impenetrable barrier to entry for your 100,000 battery of men with garages. As you lose yourself in the minutia of C++ and CAN coding, remember that your greatest impact is to continue to bring the rest of us along with you for the ride.

    1. I agree and indeed that’s the purpose of the cable diagrams. They are not precisely schematics. I try to use photos of the equipment kind of vaguely connected so they are easy to follow.

      If we do well, you won’t need C++ to build or use a car. And my intention is to make tools that are useful and understandable.

      One major annoyance is that tuner software to allow you access to proprietary ECU data, is often ITSELF deemed proprietary and oh so secret. The HP Tuners software for the Escalade actually has “licenses” letting you do like four cars. If you attempt to use it on a fifth VIN, it won’t work and demands you return to them to buy more “credits” because you are using THEIR software more than you are “licensed” for. It is absurd to the extreme.

      Jack Rickard

  4. I am no computer geek but have followed the computer scene from the early eighties. I bought mac in ’84 while in college at the educational discount price of around 2K. This was a 128k memory mac. A 3.5″ sony floppy disc you had to insert all the time to get any work done. Stewart Brand said buy into Apple about the time of the Mac introduction and I ignored his advice in print in the defunct CoEvolution Quarterly of Whole Earth Review as it was also called. I responded to Jack’s tip on Tesla and was rewarded commensurate with my risk. A hundred shares quadrupling in price and out of the frey was me. Risk averse farmer that I am though that is kind of a false image for all farmers. I can’t really share in the geeky world your working in but I appreciate your efforts. I’m staying with the tried and true w/ my dc tractor conversions and the
    AC 50 conversion upgrade of my rabbit pickup. This should perform well with the betterplace pack and the Brusa charger. Thanks for all you do

    1. Jim Fields and Michel Bertrand: I too am planning a restoration and electrification of a Mk1 VW Rabbit. I found the site where Derek Spratt is doing the “Ultimate 1983 VW Rabbit GTI Restoration” on YOUTUBE to be very enlightening. Although he is doing a straight Gasoline restoration (with Nitrous added of course) he still provides a excellent illustration of the work involved. As we see with the Karmann Ghia project, many VW are subject to the pitfalls of rust and corrosion of the years. Derek shows his methods for dealing in detail with these issues. I look forward to further correspondence on this topic. Please feel free to email me if you have questions.

  5. Heat gun, welding glove, and a vise.

    Clamp your connector gently in the vise. Heat the whole area with the heat gun. As soon as the solder flows, lift the board off the connector, wearing the glove.

    I’ve successfully removed 28 pin connectors that way. If I’m too slow, the plastic part of the connector deforms.

    OTOH, it’s probably cheaper just to mass-produce new ones than to do this, then wick up the old solder and attach new connectors to a big run of boards.

    1. Yes, that can work. In fact, it’s one of the only ways to even do something like that. But, it also tends to leave the holes a bit crusted over with solder. Then you’ve got to use desoldering braid or something and suck up all the old solder. In the end it becomes a huge fiasco and takes tons of time to do this to 100 boards. It’s basically cheaper to just say “whoops” and get totally new boards made. That all REALLY sucks but sometimes it just takes too long to do rework and results never end up looking quite as nice as you want them to.

  6. The tools to easily capture and log CAN messages at a much lower price point is something that should appeal to the “car guy” segment that wants to tweak later model cars and customize the factory displays. I know the last of the Pontiac Grand Prix have basic led / lcd type display called a Driver Information Center (DIC) that I have been considered modifing. These new tools actually look to be a good enouh value proposition to get me moving on that front.
    And the obvious next step/benefit, once the CAN is cracked open, is to convert it to elctro-magnetic drive without having to replace the factory instruments and displays.

    Very interesting set of tools; very intersting indeed.

  7. I’ve been a car guy for a very long time. Car geek might be more accurate. I’ve built 700 hp drag race cars using state of the art 1965 technology and diagnosed and repaired cars with CAN networks since they came along. I also know almost nothing about writing code, I do do some automotive programming but its more a matter of adjusting settings and uploading files. Mechanically however my aptitude is exceptional, and have been repairing cars at a professional level since 1996. These days the bulk of my spare time is spent pondering EV conversions. The Electrod will be the first of many, I’ve also taken it upon myself to enlist as many fellow car guys as possible in the 100,000 man army. Thanks for bringing us together Jack

    1. What Jack describes with the evolution of automotive technology and its impact on automotive customization reminds me of the multifunctional learning in agile product development teams first described in The New New Product Development Game (HBR, 1966): This has influenced corporate product development teams, and maybe now applies to automotive customization as well.

  8. Saw a Smith electric truck for the third time as a Staples delivery truck. This afternoon in downtown Atlanta and twice on the Interstate in the mornings. They did a nice job of advertising that it is electric powered including a sign that says this electric truck is limited to 50mph to save juice.
    And I see Smith is trying to raise capitol by playing in Over The Counter stocks.
    So perhaps they will make it; or at least delay death long enough that there will be some space at EVTV to store goodies purchased at a discount. At least Kansas is relatively near to Cape if it happens.

  9. I started out as a car/aircraft guy (mechanics licence and built a GT40 replica with a 302). I also worked with software. A background in both domains is helpful, but in my view a car guy who can follow a wiring diagram, troubleshoot electrical problems and handle email and the web should do just fine if he/she chooses well sorted standard components.

  10. Jack just saw this article

    in it they say the Zeod RC broke last June during 24hr Le Mans, not finishing race. The reason the standard transmission broke, why are they using a standard transmission with a 400-horsepower turbocharged three-cylinder and the pair of 110-kw electric motors? don’t they watch your show and know they need a better transmission?


    1. This transmission thing is getting very wierd. It’s just not something you think about. Oh, well, the transmission broke. But it is happening so often, to so many, I think we’re onto one of those “sleeper” issues. Kind of like acid reflux. Bring it up at a party and you’ll quickly learn that 90% of the entire population is on nexium, with everyone of them thinking they are the only one having the problem.

      My working theory is that we need some sort of “soft start” thing and that the damage is done subliminally to human perception. It’s not how much power we are applying, it’s going from none to a little bit, but in 10 msec.

      I’m actually thinking of adding some code to the GEVCU UQM module that if your last torque command was zero or negative, that it “spool up” in tiny values for the first five or ten licks. It sends a command every 10 msec so this would spool you up for 50 ms. Our threshold of perception is more like 200 so I don’t think anyone would ever notice. But it might make a difference with the rest of the drive train.

      This should actually more properly be in the firmware in the inverter itself.

      jack Rickard

      1. I believe they’re already doing this in non-Tesla commercial EVs. At least with the Citroën C-Zero I just bought (on the cheap), if you floor it in the lights it’ll do a really soft start off the line and only once you’ve got the mass moving it’ll leave the average ICE cars behind. Of course it only has a 47 kW powertrain, but still, I think they’ve got it covered. Tesla probably just took a gamble to get nice numbers to woo petrolheads and now they’re paying for it. Having a soft start feature in the GEVCU would probably pay off in the long run. You could always have TURBO-button in your dash to disable it when needed…

        1. Confirmed. Our i-MiEV is just the same thing. Release the breakes and it starts creeping. Meet the metal with the pedal feels almost the same but when it gets past some 10 kilometers per hour it wakes up and shoots past those gassers that felt comfortable a second ago. We never leave marks on the tarmak and we rarely shoot snowballs when starting in winter but on the pro side we never get stuck in the mud either.

          Our wheels are awfully expensive. Maybe they do it to save rubber. Nobody expects an i-MiEV to be an EVO in the first place.

          Peter and Karin

      2. Perhaps if your GEVCU could monitor current draw vs RPM of the motor you would have an idea if it is losing efficiency due to loss of alignment. Of course it would also need to know when it is on the flat, straight and narrow.
        An initial bench test before installation might be of use before adding the adapter(s).

        1. Early DIYers use to loosely couple the DC motor to the transmission and apply a low DC voltage. With a tachometer attached they would tap the motor into alignment for maximum RPM before match drilling alignment pins. It was a hillbilly way, but they got away with it.

    1. Not bad an idea. But I’d prefer integration in software. That beautifies old potentiometers with jumpy resistance as well. Does the same trick but it is easier to change a variable than a capacitor and the variable does not change its value when it grows older.

  11. I saw an i8 at the weekend. It looks absolutely amazing but I prefer the i3 and certainly wouldn’t swap it for my Ampera. According to the salesman it has fewer electric only miles than the Ampera and even with the piston engine in play it is slower 0-60 than a Model S. The rear seat is for deformed midgets and the boot space is just about big enough for Margaret Thatcher’s handbag. It did did however make the Model S sitting next to it look dowdy, which is some trick.

  12. I looked into your converte/CAN Due board design. There is a mistake in the wiring of the DB-9 connector. It does not conform to the CAN in Automation specification (abbreviated CiA). If you had used the CiA standard you could have used an existing cable OBD-M-DB9-F-ES sold by Mouser Electronics and others. I’m sorry if this had been discussed on the forum, I don’t do forums.

    1. Not to worry. CIA specification wasn’t our determinant. It matches the DB-9 to OBDII cables we can get out of Hong Kong really well. We’ll actually include those cables with the board when we get them in.

      Jack RIckard

  13. I believe Jack alluded to that fact a static rotor has windings that more resemble heating coils.
    I’ve done some efficiency graphs on a small PM motor and the initial start has the lowest efficiency but as soon as it’s rolling it’s all good.
    These start load’s of course measured from the supply. Made no distinction if it was the controller etc.

  14. Our replies don’t seem to nest any more.
    The last message was in response to Jarkko and Peters comment how most production ev’s seem to soft start from the line before they really pull.
    Point taken about a software fix for the accelerator. Highly recommended but it’s not a “will do for now” fix 😉

  15. Back to the subject of “is it my car or the manufacturers car”? Tesla stopped Otmar from purchasing parts to rebuild his Model S, and now it seems there are several others who are caught in the same situation. I read some additional complaints on Otmar’s blog post comments in the “pariah” entry . There is even a post where someone entered the actual document that Tesla asks the owners to sign. Now recently another person caught in this has been discussed on TMC forum.

    This will probably continue for a while until Tesla establishes some clear rules on how they are going to handle salvage vehicles, but it may cause the insurance rates for the vehicles to skyrocket since they cars are worthless to sell as parts or repairable vehicles to the insurance company given the current state. I’m hoping to be able to purchase a wrecked Model S cheap because of this.

    1. I buy a car, its my vehicle, not the dealers or the manufacturers, but mine. I guess Tesla is trying to treat their vehicles the same as users have to do with software…ie you don’t own its just licensed to you for your usage….if that’s the case don’t buy it.

  16. There is a change that needs to be made to the brake light relay circuit. In a car with cruse control every time the vehicle crests a hill the regen turning on the brake lights will cause the cruse control to disengage. The SPDT relay will have its common terminal go to only the brake lights. The normally open contact goes to the brake light power source. The normally closed contact goes to the output of the brake light switch. Also the this connection is fed to the cruse control andpossibly to the motor controller function that monitors the brake pedal. A dummy load may be required on this connection to keep from having a false positive during regen braking.

    This isn’t a problem with the Thing since there is no cruse control. But cars that have cruse control it can be annoying.

    1. First, cruise control has kind of limited utility in town with an electric vehicle. But more to the point, what are you looking at? What brake light relay circuit? In the GEVCU diagram for the VW Thing? As you point out, the VW THING doesn’t have cruise control.

      GEVCU provides an active low switched output through a MOSFET. You can do anything with it you want. If you hook it up to a blender, it will make you a margarita every time regen exceeds 10 Newton meters of torque.

      In any event, put the relay output to your brake light and put a diode in the circuit back to the brake switch and I think everything will be fine.

      Jack Rickard

      1. Just for curiousity, we are living at about two thirds on the backside of a (little?) pass and most of the time I have to go to the other side. Gassers are annoying, automatic gears in particular because from top to bottom their lights are switching on and of like a Chinese Christmass Tree. V8 engines, lorries and our i-MiEV easily make it down without any lights showing.

        For elder drivers seeing break lights down a pass smells like danger and I know how it feels passing a red traffic light without any breakes at all although my feet are already touching the tarmak. (Dont ask me how I know)

        I do know, other electric cars (BMW i3?) do switch the break lights on when your foot leaves the thrust pedal but I am quite sure lorries dont switch the lights on when they engage motor breaking.

        Touching the break pedal on the i-MiEV does not necessarily mean I am breaking. For speeds below 20 miles per hour I use “the breaks” going faster the other pedal.

        Peter and Karin

        1. I’m not sure where all that leads, but GEVCU makes it pretty much a configurable item. We have set a threshold of 10 Newton Meters of regenerative torque for turning on the brake lights.

          However, you have full control of the amount of regenerative braking used on both throttle and brake. You also have full control over where it is deployed. We usually provision a COAST gap between regen zone and forward drive zone making it easy to find a place where the car just coasts.

          Bottom line is there is no known issues here. And we have built in SEVERAL ways to modify the action of regenerative braking to suit PRECISELY your own tastes or desires. Kind of the point.

          Jack Rickard

      2. I use the cruse control all the time, even in the city (helps keep me legal). I live In Seattle which is not flat. I’ve had a car with a burned out brake light. I hit the turn signal to change lanes the cruse control drops out from a false positive on the brake light wire. Why because the other bulb was not there to hold the cruse control input low. Yes, it was an American car with combined brake and turn signal tail lights and no third brake light.

        No, this does not apply to the Thing. It’s the only drawing available of how you propose to hook up the brake light relay. But if people use this wiring in a car with cruse control the drop out while cresting a hill would be a problem when the drive switches from power to regen. My suggested wiring will work in all cars and allow other functions hooked to the brake light circuit to operate normally. Some of use convert cars that are more advanced than an old VW.

        1. Randy, if you are trying to implement cruise control into an ev by utilizing the original cruise control hardware, whether vacuum or electric actuated, they usually just pull on the throttle linkage. So unless you are leaving the throttle linkage, engine computer and doing a similar conversion to what Jack did on his Escalade, you have other problems more important than cruse control to solve first. Me, I’d simply trash the ICE cruse control claptrap, and just ad a couple lines of code into the GEVCU. Sample vehicle speed when you press the cruise button and then set up a pid to regulate torque to maintain speed. Could even limit to NOT regen if you wanted. On a manual or single speed tranny, you could use motor rpm and regulate that instead of vehicle mph, since rpm is available from the inverter over CAN.

          just sayin.

          1. Most of the late model cars today have a vehicle speed sensor (VSS) in the transmission be they manual or automatic. As Brian mentioned once cruise is locked-in the regen code should be temporarily bypassed. When the brake pedal is taped, or cruise unlocked the regen needs to be enabled again. How topical considering I’m just now studying hardware interrupts in Jeremy Blum’s excellent book on the Arduino. Cruise is not for everyone. I use it even in town as long as traffic is lighter than the cell-phone idiot level.

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