Hackaday Links Column Banner

Hackaday Links: September 26, 2021

Dealing with breakdowns is certainly nothing new for drivers; plenty of us have had our ride die in mid-flight, and experienced the tense moment when it happens in traffic. But the highly integrated and instrumented nature of the newest generation of electric vehicles can bring an interesting twist to the roadside breakdown, if the after-action report of a Tesla driver is any indication.

While driving on a busy road at night, driver [Pooch] reports that his Tesla Model S started beeping and flashing warnings to get to the side of the road right away. [Pooch] tried to do so, but the car died, coasted to a stop in the middle of the road, and engaged the parking brakes. The bricked Tesla would have been a sitting duck in the middle of the road but for a DOT crew who happened to be nearby and offered to provide some protection while [Pooch] waited for help. The disturbing part was the inability to get the car into any of the service modes that might let it be pushed off to the shoulder rather than stuck in traffic, something that’s trivial to do in ICE vehicles, at least older ones.

In other electric vehicle news, Chevy Bolt owners are turning into the pariahs of the parking garage. General Motors is telling Bolt EV and EUV owners that due to the risk of a battery fire, they should park at least 50 feet (15 meters) away from other vehicles, and on the top level of any parking structures. There have been reports of twelve battery fires in Bolts in the US recently, which GM says may be due to a pair of manufacturing defects in the battery packs that sometimes occur together. GM is organizing a recall to replace the modules, but isn’t yet confident that the battery supplier won’t just be replicating the manufacturing problem. The social distancing rules that GM issued go along with some fairly stringent guidelines for charging the vehicle, including not charging overnight while parked indoors. With winter coming on in the northern hemisphere, that’s going to cause a bit of inconvenience and probably more than a few cases of non-compliance that could end in tragedy.

Fans of electronic music might want to check out “Sisters with Transistors”, a documentary film about some of the pioneering women of electronic music. Electronic music has been around a lot longer than most of us realize, and the film reaches back to the 1920s with Theremin virtuoso Clara Rockmore, and continues on into the 1980s with Laurie Spiegel, whose synthesizer work has been speeding away from Earth for the last 44 years on the Golden Records aboard the Voyager spacecraft. Hackaday readers will no doubt recognize some of the other women featured, like Daphne Oram and Delia Derbyshire, who cobbled together the early Dr. Who music with signal generators, tape loops, and random bits of electronics in the pre-synthesizer days of the early 60s. We’ve watched the trailer for the film and it looks pretty good — just the kind of documentary we like.

We’re big fans of circuit sculpture around here, and desperately wish we had the patience and the skill to make something like Mohit Bhoite or Jiri Praus can make. Luckily, there’s now a bit of a shortcut — Geeek Club’s Cyber Punk PCB Construction Kit. These kits are a little like the love child of Lego and PCBWay, with pieces etched and cut from PCB stock. You punch the pieces out, clean up the mouse bites, put Tab A into Slot B, and solder to make the connection permanent. Each kit has some components for the requisite blinkenlight features, which add to the cool designs. Looks like a fun way to get someone started on soldering, or to build your own skills.

And finally, another nail was driven into the coffin of Daylight Savings Time this week, as the island nation of Samoa announced they wouldn’t be “springing ahead” as scheduled this weekend. Daylight Savings Time has become a bone of contention around the world lately, and mounting research shows that the twice-yearly clock changes cause more trouble than they may be worth. In Europe, it’s due to be banned as soon as all the member nations can agree on normal time or summer time.

In the case of Samoa, DST was put into effect in 2010 on the assumption that it would give plantation workers more productive hours in the field and save energy. Instead, the government found that the time change just gave people an excuse to socialize more, which apparently upset them enough to change the rule. So there you have it — if you don’t like Daylight Savings Time, start partying it up.

Tesla Door Handle Improvements

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.

Continue reading “Tesla Door Handle Improvements”

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

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.

Continue reading “Lithium Mine To Battery Line: Tesla Battery Day And The Future Of EVs”

Tesla Automatic Driving Under Scrutiny By US Regulators

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.

Qote from Tesla support page: "The currently enabled Autopilot and Full Self-Driving features require active driver supervision and do not make the vehicle autonomous."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.

Tesla’s Megapack Battery Burned For Days In Grid Storage Fire

Lithium rechargeable batteries have been heralded for their high-density energy storage, enabling all manner of technologies to come to fruition. From drones to practical electric cars to large-scale grid storage, the applications are endless.

The fire as seen from a drone overhead. Source: Twitter/@FireRescueVic

However, the lithium rechargeable battery has always had one major flaw–flammability. Pushed outside their operating range or otherwise tipped into thermal runaway, and they can burn ferociously as a result.

This came to pass in late July, at the Victorian Big Battery in Geelong, Australia, and it took significant effort to extinguish the blaze. Let’s take a look at the project and see how this came to occur.

Grid-Scale Storage

The Victorian Big Battery is a grid storage project similar in construction to the Hornsdale Power Reserve in neighboring South Australia. However, where the Hornsdale facility fields 194 MWh of capacity and 150MW peak power delivery, the new project aims to go much further. The Victorian project aims to install 450 MWh of capacity and deliver a peak power output of 300 MW.

Continue reading “Tesla’s Megapack Battery Burned For Days In Grid Storage Fire”

Repair Hack Saves Tesla Owner From Massive Bill

As expensive as a new car is, it almost seems like a loss leader now to get you locked into exorbitantly expensive repairs at the dealership’s service department. That’s the reason a lot of us still try to do as much of the maintenance and repairs on our cars as possible — it’s just too darn expensive to pay someone else to do it.

Case in point: this story about a hapless Tesla owner who faced a massive repair bill on his brand new car. [Donald]’s tale of woe began when he hit some road debris with his two-wheel-drive Model 3. The object hit penetrated the plastic shield over the front of the battery pack, striking a fitting in the low-pressure battery cooling plumbing. The plastic fitting cracked, causing a leak that obviously needed repair. The authorized Tesla service center gave him the bad news: that he needed a new battery pack, at a cost of $16,000. Through a series of oversights, [Donald]’s comprehensive insurance on the car had lapsed, so he was looking at funding the repair, approximately half the cost of a new Model 3, out of pocket.

Luckily, he got in touch with [Rich Benoit] of The Electrified Garage, one of the few independent garages doing Tesla repairs and customizations. The video below is queued up to the part where they actually do the repair, which is ridiculously simple. After cutting off the remains of the broken fitting with a utility knife, [Rich]’s tech was able to cut a thread in both the fitting and the battery pack, and attach them together with a brass nipple from the plumbing section of the local home store. The total bill for the repair was $700, which still seems steep to us, but a far cry from what it could have been.

Hats off to [Rich] and his crew for finding a cost-effective workaround for this issue. And if you think you’ve seen his EV repairs before, you’re right. Of course, some repairs are more successful than others.

Continue reading “Repair Hack Saves Tesla Owner From Massive Bill”

A Robot To Top Up Your Tesla

The convenience of just plugging in your car in the evening and not going into a gas station is great as long as you remember to do the plugging. You really don’t want to get caught with an empty battery while you’re in a rush. [Pat Larson]’s Tesla plugging robot might be a handy insurance policy if you count forgetfulness among your weaknesses.

The robot consists of a standard Tesla charging plug attached to a 2-axis robotic arm mounted on [Pat]’s garage wall. Everything is controlled by a Python script running on Raspberry Pi 4. After taking a picture with a camera module, it uses a Tensor Flow Lite machine learning model to determine the position of a reflector on the charging port cover. The platform moves back and forth to align with the charging port, after which it opens the charging port using the Tesla API. It then extends the arm towards the charging port, using ultrasonic proximity sensors for distance control, and again uses the camera module and Tensor Flow to look for the illuminated Tesla logo adjacent to the charging port. The charge plug is flipped out using a large servo, and after some final position adjustment, it takes the plunge. While robot won’t be winning any interior design contests, it does the job well, and adds a bit of convenience and peace of mind.

Other Tesla hacks we’ve seen include building a working Model S for $6500, turning an old Honda into a speed demon using Tesla parts, and a Casio F-91W that can unlock your Tesla.