2022: As The Hardware World Turns

January 3, 2023 by Tom Nardi 30 Comments

Well folks, we made it through another one. While it would be a stretch to call 2022 a good year for those of us in the hacking and making community, the light at the end of the tunnel does seem decidedly brighter now than it did this time 365 days ago. It might even be safe to show some legitimate optimism for the year ahead, but then again I was counting on my Tesla stocks to be a long-term investment, so what the hell do I know about predicting the future.

Eh, my kids probably weren’t going to college anyway.

Thankfully hindsight always affords us a bit of wisdom, deservedly or otherwise. Now that 2022 is officially in the rearview mirror, it’s a good time to look back on the highs (and lows) of the last twelve months. Good or bad, these are the stories that will stick out in our collective minds when we think back on this period of our lives.

Oh sure, some might wish they could take the Men in Black route and forget these last few years ever happened, but it doesn’t work that way. In fact, given the tumultuous times we’re currently living in, it seems more likely than not that at some point we’ll find ourselves having to explain the whole thing to some future generation as they stare up at us wide-eyed around a roaring fire. Though with the way this timeline is going, the source of said fire might be the smoldering remains of an overturned urban assault robot that you just destroyed.

So while it’s still fresh in our minds, and before 2023 has a chance to impose any new disasters on us, let’s take a trip back through some of the biggest stories and themes of the last year.

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We Can’t Switch To Electric Cars Until We Get More Copper

August 31, 2022 by Lewin Day 205 Comments

Reducing emissions from human activity requires a great deal of effort in many different sectors. When it comes to land transport, the idea is generally to eliminate vehicles powered by combustion engines and replace them with electric vehicles instead. At a glance, the job is simple enough. We know how to build EVs, and the technology is getting to the point where they’re capable of replacing traditional vehicles in many applications.

Of course, the reality is not so simple. To understand the problem of converting transportation to electric drive en masse, you have to take a look at the big numbers. Focus in on the metrics of copper, and you’ll find the story is a concerning one.

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Recycling Will Be Key To The Electric Vehicle Future

July 15, 2021 by Lewin Day 113 Comments

Electric vehicles have become a mainstay in the global automotive marketplace, taking on their gasoline rivals and steadily chewing out their own slice of market share, year after year. Government mandates to end the sale of polluting internal combustion engine vehicles and subsidies on cleaner cars promise to conspire to create an electric vehicle boom.

The result should be much cleaner air, as generating electricity in even the dirtiest power plants is far cleaner and more efficient than millions of individual engines puttering about the place. However, if the electric car is to reign supreme, they’ll need to be built in ever greater numbers. To do that is going to take huge amounts of certain materials that can be expensive and sometimes in very limited supply. Thus, to help support the EV boom, recycling of these materials may come to play a very important role.

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Hackaday Podcast 080: Trucks On A Wire, Seeing Sounds, Flightless Drone, And TEA Laser Strike

August 14, 2020 by Mike Szczys 1 Comment

Hackaday editors Elliot Williams and Mike Szczys flip through the index of great hacks. This week we learn of a co-existence attack on WiFi and Bluetooth radios called Spectra. The craftsmanship in a pneumatic drone is so awesome we don’t care that it doesn’t fly. Building a powerful TEA laser is partly a lesson in capacitor design. And join us in geeking out at the prospect of big rigs getting their juice from miles of overhead wires.

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (60 MB or so.)

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Choosing The Right Battery For Your Electric Vehicle Build

January 7, 2020 by Lewin Day 43 Comments

Many a hacker has looked at their scooter, bike, or skateboard, and decided that it would be even better if only it had a motor on it. Setting out to electrify one’s personal transport can be an exciting and productive journey, and one that promises to teach many lessons about mechanical and electronic engineering. Fundamentally, the key to any build is the battery, which has the utmost say in terms of your vehicle’s performance and range. To help out, we’ve prepared a useful guide on selecting the right battery for your needs.

One Chemistry To Rule Them All

Batteries come in all shapes and sizes, and a variety of different chemistries that all have their own unique properties and applications. When it comes to small electric vehicles, it’s desirable to have a battery with a low weight, compact size, plenty of current delivery for quick acceleration, and high capacity for long range.

30 years ago, options were limited to lead acid, nickel cadmium, and nickel metal hydride batteries. These were heavy, with low current output, poor capacity, and incredibly slow charge times. Thankfully, lithium polymer batteries have come along in the meantime and are more capable across the board. Offering huge discharge rates, fast charging, light weight and high capacity, they’re undeniably the ultimate choice for a high performance electric vehicle. They’re also wildly popular, and thus cheap, too!

There are some hangups, however. It’s important to keep all the cells in a pack at the same voltage in order to avoid cells back-charging each other. This can cause damage to the pack, or even explosions or fire. Maintaining the battery voltages to avoid this is called “balancing”. It can be handled in various ways, depending on the exact style of battery you’re using, as we’ll cover later.

Additionally, lithium batteries do not like being over-discharged. As a rule of thumb, it’s a good idea not to let your batteries drop below 3.0 V per cell. Failure to keep this in check can lead to ruining a pack, hurting its maximum capacity and ability to deliver current.

There are thankfully ways around these issues, and which ones you use depends on the battery you choose for your application. Continue reading “Choosing The Right Battery For Your Electric Vehicle Build” →

New Silicon Carbide Semiconductors Bring EV Efficiency Gains

November 25, 2019 by Lewin Day 47 Comments

After spending much of the 20th century languishing in development hell, electric cars have finally hit the roads in a big way. Automakers are working feverishly to improve range and recharge times to make vehicles more palatable to consumers.

With a strong base of sales and increased uncertainty about the future of fossil fuels, improvements are happening at a rapid pace. Oftentimes, change is gradual, but every so often, a brand new technology promises to bring a step change in performance. Silicon carbide (SiC) semiconductors are just such a technology, and have already begun to revolutionise the industry.

Mind The Bandgap

A graph showing the relationship between band gap and temperature for various phases of Silicon Carbide.

Traditionally, electric vehicles have relied on silicon power transistors in their construction. Having long been the most popular semiconductor material, new technological advances have opened it up to competition. Different semiconductor materials have varying properties that make them better suited for various applications, with silicon carbide being particularly attractive for high-power applications. It all comes down to the bandgap.

Electrons in a semiconductor can sit in one of two energy bands – the valence band, or the conducting band. To jump from the valence band to the conducting band, the electron needs to reach the energy level of the conducting band, jumping the band gap where no electrons can exist. In silicon, the bandgap is around 1-1.5 electron volts (eV), while in silicon carbide, the band gap of the material is on the order of 2.3-3.3 eV. This higher band gap makes the breakdown voltage of silicon carbide parts far higher, as a far stronger electric field is required to overcome the gap. Many contemporary electric cars operate with 400 V batteries, with Porsche equipping their Taycan with an 800 V system. The naturally high breakdown voltage of silicon carbide makes it highly suited to work in these applications.

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Electric Vehicles On Ice

August 16, 2019 by Sharon Lin 10 Comments

This winter, a group of electric vehicle enthusiasts, including [Dane Kouttron], raced their homemade electric go-karts on the semi-frozen tundra nearby as part of their annual winter tradition. These vehicles are appropriately named Atomic Thing and Doom Sled, and need perfect weather conditions to really put them to the test. You want a glass-like race track but snowfall on ice freezes into an ice-mush intermediate that ends up being too viscous for high-speed ice vehicles. The trick is to watch for temperatures that remain well below zero without snow-like precipitation.

The group is from the community makerspace out of MIT known as MITERS and already have EV hacking experience. They retrofitted their VW Things vehicle (originally built for a high speed electric vehicle competition) to squeeze even more speed out of the design. Starting out with an 8-speed Shimano gearbox and a 7kW motor, they assembled a massive 24S 10P battery out of cylindrical A123 cells salvaged from a Prius A123 Hymotion program. This monster operates at 84V with a 22AH capacity, plenty for power for the team to fully utilize the motor’s potential.

The battery is ratchet strapped to the back of the Atomic Thing to provide more traction on the ice. It must feel just like riding on top of a different kind of rocket.

Original configuration of battery packs

Battery packs ratchet strapped

They tried using ice skates in the front of the Atomic Thing, but the steering was difficult to control over rough ice. Studded solid tires perform quite well, resulting in less jarring movement for the driver. Doom Sled is a contraption built from a frame of welded steel tube and a mountainboard truck with ice skate blades for steering. The motor — a Motenegy DC brush [ME909] — was salvaged from a lab cleanout, transferring power to the wheels through a chain and keyed shaft. The shaft-to-wheel torque was duly translated over two keyed hub adapters.

The crew fitted a seat from a longscooter and made a chain guard from aluminum u-channel to keep the flying chain away from the driver’s fingers. The final user interface includes a right-hand throttle and a left-hand “electric brake” (using resistors to remove the stored energy quickly to combat the enormous inertia produced by the vehicle).

Overall, ice racing was a success! You can see the racing conditions were just about perfect, with minimal ice mush on the lake. Any rough patches were definitely buffered smooth by the end of the day.

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