speed

38 Articles

Train Speed Signaling Adapted For Car

September 11, 2024 by 33 Comments

One major flaw of designing societies around cars is the sheer amount of signage that drivers are expected to recognize, read, and react to. It’s a highly complex system that requires constant vigilance to a relatively boring task with high stakes, which is not something humans are particularly well adapted for. Modern GPS equipment can solve a few of these attention problems, with some able to at least show the current speed limit and perhaps an ongoing information feed of the current driving conditions., Trains, on the other hand, solved a lot of these problems long ago. [Philo] and [Tris], two train aficionados, were recently able to get an old speed indicator from a train and get it working in a similar way in their own car.

The speed indicator itself came from a train on the Red Line of the T, Boston’s subway system run by the Massachusetts Bay Transportation Authority (MBTA). Trains have a few unique ways of making sure they go the correct speed for whatever track they’re on as well as avoid colliding with other trains, and this speed indicator is part of that system. [Philo] and [Tris] found out through some reverse engineering that most of the parts were off-the-shelf components, and were able to repair a few things as well as eventually power everything up. With the help of an Arduino, an I/O expander, and some transistors to handle the 28V requirement for the speed indicator, the pair set off in their car to do some real-world testing.

This did take a few tries to get right, as there were some issues with the power supply as well as some bugs to work out in order to interface with the vehicle’s OBD-II port. They also tried to use GPS for approximating speed as well, and after a few runs around Boston they were successful in getting this speed indicator working as a speedometer for their car. It’s an impressive bit of reverse engineering as well as interfacing newer technology with old. For some other bits of train technology reproduced in the modern world you might also want to look at this recreation of a train whistle.

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Art of 3D printer in the middle of printing a Hackaday Jolly Wrencher logo

3D Printering: Speed Is So Hot Right Now

January 29, 2024 by 34 Comments

Speed in 3D printing hasn’t been super important to everyone. Certainly, users value speed. But some value quality even more highly, and if gaining quality means giving up speed, then so be it. That’s more or less how things stood for a while, but all things change.

The landscape of filament-based 3D printing over the past year or so has made one thing clear: the market’s gotten a taste of speed, and what was once the domain of enthusiasts installing and configuring custom firmware is now a baseline people will increasingly expect. After all, who doesn’t want faster prints if one doesn’t have to sacrifice quality in the process?

Speed vs. Quality: No Longer a Tradeoff

Historically, any meaningful increase in printing speed risked compromising quality. Increasing print speed can introduce artifacts like ringing or ghosting, as well as other issues. Printing faster can also highlight mechanical limitations or shortcomings that may not have been a problem at lower speeds. These issues can’t all be resolved by tightening some screws or following a calibration process.

The usual way to get into higher speed printing has been to install something like Klipper, and put the necessary work into configuring and calibrating for best results. Not everyone who prints wishes to go this route. In 3D printing there are always those more interested in the end result than in pushing the limits of the machine itself. For those folks, the benefits of speedy printing have generally come at too high a cost.

That’s no longer the case. One can now buy a printer that effectively self-calibrates, offers noticeably increased printing speeds over any earlier style machines, and does it at a reasonable price.

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50-Year-Old Program Gets Speed Boost

November 7, 2023 by 19 Comments

At first glance, getting a computer program to run faster than the first electronic computers might seem trivial. After all, most of us carry enormously powerful processors in our pockets every day as if that’s normal. But [Mark] isn’t trying to beat computers like the ENIAC with a mobile ARM processor or other modern device. He’s now programming with the successor to the original Intel integrated circuit processor, the 4040, but beating the ENIAC is still little more complicated than you might think with a processor from 1974.

For this project, the goal was to best the 70-hour time set by ENIAC for computing the first 2035 digits of pi. There are a number of algorithms for performing this calculation, but using a 4-bit processor and an extremely limited memory of only 1280 bytes makes a number of these methods impossible, especially with the self-imposed time limit. The limited instruction set is a potential bottleneck as well with these early processors. [Mark] decided to use [Fabrice Bellard]’s algorithm given these limitations. He goes into great detail about the mathematics behind this method before coding it in JavaScript. Generating assembly language from a working JavaScript was found to be fairly straightforward.

[Mark] is also doing a lot of work on the 4040 to get this program running as well, including upgrades to the 40xx tool stack, the compiler and linker, and an emulator he’s using to test his program before sending it to physical hardware. The project is remarkably well-documented, including all of the optimizations needed to get these antique processors running fast enough to beat the ENIAC. We won’t spoil the results for you, but as a hint to how it worked out, he started this project using the 4040 since his original attempt using a 4004 wasn’t quite fast enough.

Latency Meter For Accurate Gaming

September 19, 2023 by 15 Comments

The gaming world experienced a bit of a resurgence in 2020 that is still seen in the present day. Even putting aside the effects from the pandemic, the affordability and accessibility has arguably never been better. Building a gaming PC can have its downsides, though, and a challenging issue to troubleshoot is input lag or input latency. This is something that’s best measured with standalone hardware, and if this is an issue on your setup you may want to take a look at this latency meter.

Unlike other measurement devices that use the time between a mouse button input and the monitor’s display of a bullet or shooting event, this one looks at mouse movement and the change in the scene instead. This makes it much more versatile than other methods since it’s independent of specific actions, and can be used in any game without any specific events needed to perform the measurement. A camera phototransistor is placed on the monitor’s top edge and the Arduino-based device sends mouse commands to the computer while measuring the time between those commands and the shift in the image on the monitor.

The project is open source, so with the right hardware it’s possible to build one to troubleshoot latency issues or just to learn more about a particular hardware configuration’s behavior. Arduinos and other microcontrollers have been doing all kinds of things by pretending to be human interface devices like this for a while now. One of our favorites of late was this effects pedal that replicates musical effects on mice and keyboards.

A black race car with white text of sponsors moves across an asphalt surface. There is a blue wall and a green, grassy field in the background. The car has white and red stripes as well.

Students Set EV Acceleration World Record

September 14, 2023 by 29 Comments

Humans have a need for speed, and students from the Academic Motorsports Club Zurich (AMZ) have set a new acceleration record for an electric vehicle with a 0 to 100 km/h (0 to 62 mph) time of 0.956 seconds.

The mythen features four custom electric hub motors with a total output of 240 kW and a vehicle weight of 140 kg (309 lb) thanks to the use of carbon fiber and aluminum honeycomb. The car was able to get up to speed over only 12.3 m (40 ft)! As with many student design team projects, every component was hand built and designed to optimize the power to weight ratio of the vehicle.

The students from ETH Zurich and Lucerne University of Applied Sciences and Arts were excited to regain the record from the team at the University of Stuttgart, having previously held the title in 2014 and 2016. We suspect that they will find any European EV maker’s engineering department excited for the chance to hire them come graduation.

If you want to go fast at a smaller scale, checkout 3D printing RC car wheels for speed, and if you’d rather ride the rails at an accelerated rate, here’s an article on high speed rail.

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Computer Speed Gains Erased By Modern Software

July 2, 2023 by 284 Comments

[Julio] has an older computer sitting on a desk, and recorded a quick video with it showing how fast this computer can do seemingly simple things, like open default Windows applications including the command prompt and Notepad. Compared to his modern laptop, which seems to struggle with even these basic tasks despite its impressive modern hardware, the antique machine seems like a speed demon. His videos set off a huge debate about why it seems that modern personal computers often appear slower than machines of the past.

After going through plenty of plausible scenarios for what is causing the slowdown, [Julio] seems to settle on a nuanced point regarding abstraction. Plenty of application developers are attempting to minimize the amount of development time for their programs while maximizing the number of platforms they run on, which often involves using a compatibility layer, which abstracts the software away from the hardware and increases the overhead needed to run programs. Things like this are possible thanks to the amount of computing power of modern machines, but not without a slight cost of higher latency. For applications developed natively, the response times would be expected to be quite good, but fewer applications are developed natively now including things that might seem like they otherwise would be.  Notepad, for example, is now based on UWP.

While there are plenty of plausible reasons for these slowdowns in apparent speed, it’s likely a combination of many things; death by a thousand cuts. Desktop applications built with a browser compatibility layer, software companies who are reducing their own costs by perhaps not abiding by best programming practices or simply taking advantage of modern computing power to reduce their costs, and of course the fact that modern software often needs more hardware resources to run safely and securely than equivalents from the past.

Using Sonar To Measure Traffic Speeds

June 19, 2023 by 21 Comments

One of the most common ways of measuring the speed of a vehicle is by using radar, which typically involves generating radio waves, directing them at a moving vehicle, and measuring the various ways that they return to the device. This is a tried-and-true method, but can be expensive and technically complex. [GeeDub] wanted an easier way of measuring vehicles passing by his home, so he switched to using sonar instead to measure speeds based on the sounds the cars generate themselves.

The method he is using is similar to passive sonar in submarines, which can locate objects underwater based on the sounds they produce. After a false start attempting to measure Doppler shift, he switched to time correlation using two microphones, essentially using stereo audio input to detect subtle differences in arrival times of various sounds to detect the positions of passing vehicles. Doing this fast enough and extrapolating the data gathered, speed information can be calculated. For the data gathering and calculation, [GeeDub] is using a Raspberry Pi to help keep costs down, and some further configuration of the microphones and their power supplies were also needed to ensure quality audio was gathered.

With the system in place in a window, it detected around 9,000 vehicles over a three-day period. The software generates a normal distribution of vehicle speeds for this time, with the distribution centered on around 35 MPH, slightly above the posted speed limit of 30. As long as there’s a clear line of sight to the road using this system it’s just as effective as some other passive systems we’ve seen to measure vehicle speed. Of course, active speed measurement systems are not out of the realm of possibility if you’re willing to spend a little more.