Arduino Gear Shift Indicator Finds ‘Em So You Won’t Grind ‘Em

March 20, 2024 by Dan Maloney 75 Comments

Now, it’s been a shamefully long time since we’ve driven a car with a manual transmission, but as we recall it was pretty straightforward. It certainly didn’t require a lot of help with the shifting pattern, at least not enough to require a technical solution to know what gear you’re in. But then again, we suspect that’s not really the point of [upir]’s latest build.

Oh sure, it’s pretty cool to display your current gear selection on a little LCD screen using an Arduino. And [upir] promises a follow-up project where the display goes inside the shifter knob, which will be really cool. But if you take a look at the video below, you’ll see that the real value of this project is the stepwise approach he takes to create this project. [upir] spends most of the time in the video below simulating the hardware and the code of the project in Wokwi, which lets him make changes and tune the design up before committing anything to actual hardware.

That turned out to be particularly useful with this build since he chose to use analog Hall sensors to detect the shift lever position and didn’t know exactly how that would work. Wokwi let him quickly build a virtual prototype for one sensor (using a potentiometer as a stand-in, since the simulator lacked a Hall sensor model), then quickly expand to the four sensors needed to detect all six gear positions.

By the time his simulation was complete, the code was almost entirely written. [upir] also walks us through his toolchains for both designing the graphics and laying out the PCB, a non-trivial task given the odd layout. We particularly enjoyed the tip on making smooth curved traces around the oval cutout for the shift lever in the board.

The video below is on the longish side, but it’s chock full of great little tips. Check out some more of [upir]’s work, like his pimped-out potentiometer or his custom animations on 16×2 LCDs.

Continue reading “Arduino Gear Shift Indicator Finds ‘Em So You Won’t Grind ‘Em” →

Running Power And Data Over Just Two Wires

March 19, 2024 by Lewin Day 50 Comments

When you’re hooking up equipment across a vehicle, you’re often stuck sending power and data to and from things like sensors or actuators. The more wires you have to run, the more hassle, so it’s desirable to get this number as low as possible. That’s an especially big deal in the world of cycling electronics, where every additional gram is considered a drawback. To this end, companies have developed two-wire methods of sending power and data together, and now, [Keith Wakeham] has devised his own way of doing so.

[Keith] was inspired by Shimano’s E-Tube system which is fairly fancy in its encoding schemes, but he went his own way. His concept relied on old-school On-Off Keying methods to take a signal and capacitively couple a signal into power lines. He explains the theory behind the method, and shares schematics that can be used to actually communicate over power lines. Then, he shows off the real hardware that he built to test the concept for himself.

The results? Good! [Keith] was able to maintain speeds of 57,600 bits/second even with an electrically-noisy gear motor operating on the lines. That’s more then enough for all kinds of applications.

If you’ve got your own data-over-powerline hacks, don’t hesitate to let us know. Continue reading “Running Power And Data Over Just Two Wires” →

Shôtarô Kaneda’s Motorcycle, For Real

March 17, 2024 by Jenny List 25 Comments

For fans of the iconic anime Akira, there’s only one way to traverse the mean streets of post-apocalyptic neo-Tokyo, and that’s the futuristic mount of motorcycle gang leader Shôtarô Kaneda. It’s a low-down feet-forward machine with, we’re told, “Ceramic double-rotor two-wheel drive,” which we’re guessing is some kind of hybrid electric drive with what sounds like a gas-turbine motor. Over the years, there have been a few different attempts to create a real version of Kaneda’s bike, and we’re pleased to see the latest from ヲタ工房「ポンちゃンネル」(Ota Kobo “Ponchanner”). It uses a twin-cylinder Kawasaki motor in an entirely custom-made frame, with dual single-sided swingarms front and rear and hub-centre steering.

The full build in the video below the break is pretty long but well worth a watch, and it includes a lot of very highly skilled metalwork. It’s an interesting choice not to attempt to make a direct replica of Kaneda’s bike. Still, we think some of the differences are dictated by this being very much a roadworthy and everyday-rideable machine.

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The Insurance Buys The Wheelchair, But Not The App To Run It

March 9, 2024 by Jenny List 35 Comments

The writer Cory Doctorow coined the term enshittification to describe the way that services decline in quality as their users become the product. He was talking about online services when he came up with the word, but the same is very much true when it comes to hardware. Items which once just worked now need apps and online services, with marginal benefit to the user if any. It’s one thing when it’s your soundbar or your washing machine, but thanks to Lemmy user [@win95] from the Netherlands we’ve seen a far more egregious example. People with disabilities are being provided with new powered wheelchairs through their medical insurance, but are then discovering that unaffordable in-app purchases are needed to use their features. Continue reading “The Insurance Buys The Wheelchair, But Not The App To Run It” →

Older Nissan Leafs Lose Their App, Are They The First Of Many?

March 7, 2024 by Jenny List 103 Comments

There was a time when all you needed to use your car was a key. On older vehicles it was a traditional metal key, on more recent ones it had some kind of RFID chip for the immobilizer. As vehicles have become more and more computers on wheels though, the key has disappeared in favor of an electronic key using RF, and in many cases a smartphone application. It’s even used as a selling point: “Look how amazing our car is, you open it with an app!”

Now the obvious flaw is beginning to show in this strategy, as Nissan Leafs made before 2016 and on the road in the UK are to have their app support withdrawn. The manufacturer cites the withdrawal of 2G services, but this seems a little fishy when you consider that the older networks will continue to exist in some form until 2030.

Frankly, there’s part of us that welcomes this news. On one hand, it affects relatively few early adopters. But at the same time, it has the promise of finally educating a gullible public that while a car may last into its second or third decade, the superfluous technology with which it has been loaded probably won’t. If it makes consumers clamor for longer support, or better built vehicles, it can only be a good thing. We’re guessing stories like this will become increasingly common in the next few years — luckily for Leaf owners, its relatively trivial loss of functionality won’t be the worst among them.

If the carmakers have forgotten how to make a vehicle without the dross, we’d be delighted to remind them.

Header: Kārlis Dambrāns, CC BY 2.0.

Thanks [CampGareth] for the tip.

How Powerful Should An Electric Bike Be? The UK Is Asking

March 6, 2024 by Jenny List 119 Comments

As electric drives sweep their way to dominance in the automotive world, there’s another transport sector in which their is also continuing apace. Electric-assisted bicycles preserve the feeling of riding a bike as you always have, along with an electric motor to effortlessly power the rider over hill and dale. European electric two-wheelers are limited to a legal top speed of about 15 miles per hour and a 250 watt motor, but in a post-Brexit dash for independence the British government are asking whether that power should be increased to 500 watts.

The Westminster politicians think such a move will make electric bikes more attractive to consumers, and along with a move to motorcycle-style throttles rather than pedal-to-go throttles they want it to accelerate the take-up of greener transport in a country with plenty of hills. Meanwhile cycling groups and safety groups are concerned, the former whether the move is needed at all, and the latter over the fire risk from more powerful battery packs.

The Hackaday electric bike stable gives us a bit of experience on the matter, and our take is that with a 15 mile-per-hour limit there’s little point in upping the motor power. There’s a 350 watt European limit for three-wheelers though, which we could see would really benefit from a raise if applied to cargo bikes. We can however see that a readily-available supply of cheap 500 W motors would be worth having.

Retrotechtacular: The Free Piston Engine

March 4, 2024 by Jenny List 20 Comments

We all know how a conventional internal combustion engine works, with a piston and a crankshaft. But that’s by no means the only way to make an engine, and one of the slightly more unusual alternatives comes to us courtesy of a vintage Shell Film Unit film, The Free Piston Engine, which we’ve placed below the break. It’s a beautiful period piece of mid-century animation and jazz, but it’s also an introduction to these fascinating machines.

We’re introduced to the traditional two-stroke diesel engine as thermally efficient but not smooth-running, and then the gas turbine as smooth but much more inefficient. The free piston engine, a design with opposed pistons working against compressed air springs and combining both compression and firing strokes in a single axis, doesn’t turn anything in itself, but instead works as a continuous supplier of high pressure combustion gasses. The clever part of this arrangement is that these gasses can then turn the power turbine from a gas turbine engine, achieving a smooth engine without compromising efficiency.

This sounds like a promising design for an engine, and we’re introduced to a rosy picture of railway locomotives, ships, factories, and power stations all driven by free piston engines. Why then, here in 2024 do we not see them everywhere? A quick Google search reveals an inordinately high number of scientific review papers about them but not so many real-world examples. In that they’re not alone, for alternative engine designs are one of those technologies for which if we had a dollar for every one we’d seen that didn’t make it, as the saying goes, we’d be rich.

It seems that the problem with these engines is that they don’t offer the control over their timing that we’re used to from more conventional designs, and thus the speed of their operation also can’t be controlled. The British firm Libertine claim to have solved this with their line of linear electrical generators, but perhaps understandably for commercial reasons they are a little coy about the details. Their focus is on free piston engines as power sources for hybrid electric vehicles, something which due to their small size they seem ideally suited for.

Perhaps the free piston engine has faced its biggest problem not in the matter of technology but in inertia. There’s an old saying in the computer industry: “Nobody ever got fired for buying IBM“, meaning that the conventional conservative choice always wins, and it’s fair to guess that the same applies anywhere a large engine has been needed. A conventional diesel engine may be a complex device with many moving parts, but it’s a well-understood machine that whoever wields the cheque book feels comfortable with. That’s a huge obstacle for any new technology to climb. Meanwhile though it offers obvious benefits in terms of efficiency, at the moment its time could have come due to environmental concerns, any internal combustion engine has fallen out of fashion. It’s possible that it could find a life as an engine running on an alternative fuel such as hydrogen or ammonia, but we’re not so sure. If new free piston engines do take off though, we’ll be more pleased than anyone to eat our words.

Continue reading “Retrotechtacular: The Free Piston Engine” →