Tesla Door Handle Improvements

September 16, 2021 by Chris Lott 31 Comments

Automotive engineer and former Tesla employee [SuperfastMatt] takes at look at the notorious Tesla door handle design and how it’s changed over the years (see the video below the break). The original handle design consisted of many moving parts, switches and wires which were prone to failure. Strictly speaking, the door handle is located on the outside of the car’s interior. While it’s sheltered from direct exposure to the elements, it still experiences the extremes of temperature, humidity, and condensation. The handles were so prone to failure that a cottage industry sprang up to provide improved parts and replacements.

Tesla made various improvements over the years, culminating in the latest version which [Matt] reviews in this video. Nearly all the failure points have been eliminated, and the only moving parts, other than the handle itself, is a magnetic sensor to detect handle motion (previously this was sensed by microswitches). [Matt] indelicately opens up the control module, and discovers an NXP programmable angle sensor ( KMA215 ). This all-in-one sensor detects the angle of a magnetic field, and reports it over an automotive communications bus that’s become more and more common over the last ten years: Single Edge Nibble Transmission (SENT) aka SAE J2716. SENT is a low-cost, transmit-only protocol designed for sensors to send data to the ECU. Check out [Matt] decoding it on the oscilloscope and Raspberry Pi in the video — it looks pretty simple at first glance.

We agree with [Matt]’s conclusion that the door handle design has been significantly improved with this latest iteration, questions of whether one needs a retracting door handle aside. If you’d like to learn more about SENT, here is a tutorial written by IDT (now Renasas) applications engineer Tim White. This isn’t [Matt]’s first encounter with a Tesla door handle — back in 2012 we covered his project which used one to dispense beer. Thanks to [JohnU] for sending in this tip.

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Lithium Mine To Battery Line: Tesla Battery Day And The Future Of EVs

September 14, 2021 by Maya Posch 15 Comments

After last year’s Tesla Battery Day presentation and the flurry of information that came out of it, [The Limiting Factor] spent many months researching the countless topics behind Tesla’s announced plans, the resource markets for everything from lithium to copper and cobalt, and what all of this means for electrical vehicles (EVs) as well as batteries for both battery-electric vehicles (BEVs) and power storage.

A number of these changes are immediate, such as the use of battery packs as a structural element to save the weight of a supporting structure, while others such as the shift away from cobalt in battery cathodes being a more long-term prospective, along with the plans for Tesla to set up its own lithium clay mining operation in the US. Also impossible to pin down: when the famous ‘tabless’ 4680 cells that Tesla plans to use instead of the current 18650 cells will be mass-produced and when they will enable the promised 16% increase.

Even so, in the over 1 hour long video (also linked below after the break), the overall perspective seems fairly optimistic, with LFP (lithium iron phosphate) batteries also getting a shout out. One obvious indication of process to point out is that the cobalt-free battery is already used in Model 3 Teslas, most commonly in Chinese models.

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Making A Car Key From A Ratcheting Wrench

September 12, 2021 by Lewin Day 45 Comments

Car keys these days are remarkably complex beasts. Covered in buttons and loaded with security transponders, they often cost hundreds of dollars to replace if you’re unlucky enough to lose them. However, back in the day, keys used to just be keys — a hunk of metal in a mechanical pattern to move some levers and open a door. Thus, you could reshape a wrench into a key for an old car if that was something you really wanted to do.

The concept is simple. Take a 12mm ratcheting wrench, and shape the flat section into a profile matching that of a key for an older car without any electronic security features. The first step is to cut down the shaft, before grinding it down to match the thickness and width of the original key.

The profile of the key is then drawn onto the surface, and a Dremel used with a cutting disc to create the requisite shape. Finally, calipers are used to mark out the channels to allow the key to slide into the keyway, before these are also machined with the rotary tool.

Filing and polishing cleans up the final result to create a shiny, attractive ratchet wrench key. Even better, it does a great job of opening the car, too.

Similar machining techniques can be used to duplicate a key from just a photo (something I did back in 2019 to prank my friend). Alternatively, 3D printing can be great for reproducing even high-security keys. Video after the break.

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Hacker Claims Honda And Acura Vehicles Vulnerable To Simple Replay Attack

August 30, 2021 by Lewin Day 25 Comments

Keyless entry has become a standard feature on virtually all cars, where once it was a luxury option. However, it’s also changed the way that thieves approach the process of breaking into a car. After recent research, [HackingIntoYourHeart] claims that many modern Honda and Acura vehicles can be accessed with a simple replay attack using cheap hardware.

It’s a bold claim, and one that we’d love to see confirmed by a third party. The crux of the allegations are that simply recording signals from a Honda or Acura keyfob is enough to compromise the vehicle. Reportedly, no rolling code system is implemented and commands can easily be replayed.

Given these commands control features like unlocking the doors, opening the trunk, and even remote starting the vehicle, it’s a concerning situation. However, it’s also somewhat surprising. Rolling code technology has been around for decades, and makes basic replay attacks more difficult. Range extender attacks that target keyfobs sitting inside homes or gas stations are more common these days.

Whether Honda has made a security faux pas, or if there’s something more at play here, remains to be seen. If you’ve got more information, or have been able to recreate the same hack on your own Honda, be sure to let us know.

Tesla Automatic Driving Under Scrutiny By US Regulators

August 16, 2021 by Al Williams 66 Comments

The US National Highway Traffic Safety Administration (NHTSA) has opened a formal investigation about Tesla’s automatic driving features (PDF), claiming to have identified 11 accidents that are of concern. In particular, they are looking at the feature Tesla calls “Autopilot” or traffic-aware cruise control” while approaching stopped responder vehicles like fire trucks or ambulances. According to the statement from NHTSA, most of the cases were at night and also involved warning devices such as cones, flashing lights, or a sign with an arrow that, you would presume, would have made a human driver cautious.

There are no details about the severity of those accidents. In the events being studied, the NHTSA reports that vehicles using the traffic-aware cruise control “encountered first responder scenes and subsequently struck one or more vehicles involved with those scenes.”

Despite how they have marketed the features, Tesla will tell you that none of their vehicles are truly self-driving and that the driver must maintain control. That’s assuming a lot, even if you ignore the fact that some Tesla owners have gone to great lengths to bypass the need to have a driver in control. Tesla has promised full automation for driving and is testing that feature, but as of the time of writing the company still indicates active driver supervision is necessary when using existing “Full Self-Driving” features.

We’ve talked a lot about self-driving car safety in the past. We’ve also covered some of the more public accidents we’ve heard about. What do you think? Are self-driving cars as close to reality as they’d like you to believe? Let us know what you think in the comments.

A New Flying Car Illustrates The Same Old Problems

August 9, 2021 by Lewin Day 98 Comments

For almost as long as there have been cars and planes, people have speculated that one day we will all get around in flying cars. They’d allow us to “avoid the traffic” by flying through the air instead of sitting in snarling traffic jams on the ground.

The Klein Vision AirCar hopes to be just such a panacea to our modern traffic woes, serving as a transformable flying car that can both soar through the air and drive on the ground. Let’s take a look at the prototype vehicle’s achievements, and the inherent problems with the underlying flying car concept.

It Flies and Drives

The AirCar is a somewhat futuristic looking, yet simultaneously dated, vehicle. It’s a two-seater with a big bubble canopy for the driver and a single passenger. At the rear, there’s a propeller and twin-boom tail, while the folding wings tuck along either side of the vehicle in “car” mode. At the flick of a switch, the wings fold out and lock in place, while the tail extends further out to the rear. The conversion from driving mode to flight mode takes on the order of a few minutes. The powerplant at the heart of the vehicle is a 160-horsepower BMW engine which switches between driving the wheels and the propeller as needed.

Unlike some concepts we’ve explored in the past, the AirCar has successfully demonstrated itself as a working flying car without incident. Additionally, it did so as a single vehicular package, without removable wings or other such contrivances. On June 28th, 2021, it successfully flew from an airport in Nitra, Slovakia, down to the neighbouring city of Bratislava in 35 minutes – roughly half the time it takes by car. Company founder Stefan Klein was behind the controls, casually driving the vehicle downtown after the successful landing. Continue reading “A New Flying Car Illustrates The Same Old Problems” →

Custom Instrument Cluster For Aging Car

August 1, 2021 by Bryan Cockfield 32 Comments

All of the technological improvements to vehicles over the past few decades have led to cars and trucks that would seem borderline magical to anyone driving something like a Ford Pinto in the 1970s. Not only are cars much safer due to things like crumple zones, anti-lock brakes, air bags, and compulsory seat belt use, but there’s a wide array of sensors, user interfaces, and computers that also improve the driving experience. At least, until it starts wearing out. The electronic technology in our modern cars can be tricky to replace, but [Aravind] at least was able to replace part of the instrument cluster on his aging (yet still modern) Skoda and improve upon it in the process.

These cars have a recurring problem with the central part of the cluster that includes an LCD display. If replacement parts can even be found, they tend to cost a significant fraction of the value of the car, making them uneconomical for most. [Aravind] found that a 3.5″ color LCD that was already available fit perfectly in the space once the old screen was removed, so from there the next steps were to interface it to the car. These have a CAN bus separated from the main control CAN bus, and the port was easily accessible, so an Arduino with a RTC was obtained to handle the heavy lifting of interfacing with it.

Now, [Aravind] has a new LCD screen in the console that’s fully programmable and potentially longer-lasting than the factory LCD was. There’s also full documentation of the process on the project page as well, for anyone else with a Volkswagen-adjacent car from this era. Either way, it’s a much more economical approach to replacing the module than shelling out the enormous cost of OEM replacement parts. Of course, CAN bus hacks like these are often gateway projects to doing more involved CAN bus projects like turning an entire vehicle into a video game controller.

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