GPS Overlays Give Real Life Racing A Video Game Feel

Racing is certainly exciting for the person rocketing around the track fast enough to get the speedometer into the triple digits, and tends to be a decent thrill for the spectators if they’ve got good seats. But if you’re just watching raw race videos on YouTube from the comfort of your office chair it can be a bit difficult to appreciate. There’s a lack of context for the viewer, and it can be hard to get the same sense of speed and position that you’d have if you saw the event first hand.

In an effort to give his father’s racing videos a bit more punch, [DusteD] came up with a clever way of adding video game style overlays to the recordings. The system provides real-time speed, lap times, and even a miniature representation of the track complete with a marker to show where the action is taking place. The end result is that recordings of Dad’s exploits on the track could pass as gameplay footage from Gran Turismo (we know GT doesn’t have motorcycles, but you get the idea).

The first part of the system is the tracker itself, which consists of a GPS receiver, an Arduino Pro Micro, and an SD card module. [DusteD] powers the device with two 18650 cells in parallel, and a DC-DC boost converter to step it up to 5V. Everything is contained in a 3D printed enclosure that he designed in OpenSCAD, with the only external elements being a toggle switch, a momentary switch, and most critically, a set of LEDs.

These LEDs play into the second part of the system, the software. The blinking LEDs are positioned so they’ll get picked up by the camera, which is then used to help synchronize the data stored on the SD card with the video. [DusteD] came up with some software that will take the speed and position information from the card, and turn it into PNG files with transparent backgrounds. These are then placed on top of the video with the help of FFmpeg. It takes a little adjustment to get everything lined up properly, but as the video after the break shows the end result is very impressive.

This build reminds us of the Raspberry Pi powered GPS helmet camera we featured a few years back, and it’s interesting to see how the two projects achieved what’s essentially the same goal in different ways.

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OpenSCAD handles the Math in 3D Printed Holder for Magnetic Spheres

3D printed holder mounted to bike wheel, fitting precisely 38 magnetic spheres around its perimeter. Tedious math? Not if you make OpenSCAD do it.

Off-the-shelf components are great; the world and our work simply wouldn’t be the same without. But one of the constraints is that one has to design around them, and that’s what led [Antonio Ospite] to create a parametric design in OpenSCAD for a 3D printed holder which snugly fits a number of magnetic spheres around its diameter.

If that sounds a bit esoteric, it will become much clearer in the context of [Antonio]’s earlier work in making a DIY rotary encoder out of a ring of magnetic spheres. He found that such a ring in front of two Hall effect sensors was low in cost, high in precision, and thanks to 3D printing it also had a lot of potential for customizing. But hampering easy design changes was the need for the spheres to fit snugly around whatever shape was chosen for the hardware, which meant constraints on the encoder diameter.

In this case, [Antonio] wished to create an encoder that could be attached to a bicycle wheel but needed to know what outer diameter would best fit a ring of magnetic balls perfectly, given that the balls were each 5 mm. OpenSCAD did the trick, yielding a design that fit the bike wheel and spokes while perfectly nestling 38 magnetic balls around the outside edge with a minimum of wasted space.

OpenSCAD is a CAD program that’s really more like a programming language than anything else. For those who are not familiar with it, [Brian Benchoff] walked through how to make a simple object in OpenSCAD, and [Elliot] has sung the praises of a few advanced functions. Now that this project makes DIY encoders easier, perhaps they could be used to add intuitive new controls to OpenSCAD itself.

The A to Z of Building Your Own Keyboard

We’ve featured a number of people who’ve taken the plunge and created their own customized keyboard; at this point it’s safe to say that there’s enough information and source code out there that anyone who’s looking to build their own board won’t have much trouble figuring out how to do so. That being said, it’s nice to have a comprehensive at a process from start to finish. Why sift through forum posts and image galleries looking for crumbs if you don’t have to?

That’s precisely what makes this write-up by [Maarten Tromp] so interesting. He walks the reader through every step of the design and creation of his customized keyboard, from coming up with the rather unique layout to writing the firmware for its AVR microcontroller. It’s a long read, filled with plenty of tips and tricks from a multitude of disciplines.

After looking at other custom boards for inspiration, [Maarten] used OpenSCAD to create a 3D model of his proposed design, and had it printed at Shapeways. His electronics are based around an Atmel ATMega328P using vUSB, and Microchip MCP23017 I/O expanders to connect all the keys. He wrapped it all up by designing a PCB in gEDA PCB and having it sent off for production. As a testament to his attention to detail, everything mated up on the first try.

[Maarten] is happy with the final product, but mentions that in a future revision he would like to add RGB lighting and use a microcontroller that has native USB support. He’d also like to drop the I/O expanders and switch over to Charlieplexing for the key matrix.

From uncommon layouts to diminutive technicolor beauties, it seems there’s no end of custom keyboards in sight. We aren’t complaining.

3D Printering: When an STL File is Not Quite Right

STL files are everywhere. When there’s something to 3D print, it’s probably going to be an STL. Which, as long as the model is good just as it is, is no trouble at all. But sooner or later there will be a model that isn’t quite right in some way and suddenly project progress hits a snag.

When models interface with other physical things, those other components may not always be exactly as the designer expected. Being mindful about such potential inconsistencies during the design phase can help prevent problems, but it’s not always avoidable. The reason it’s a problem is because an STL file represents a solid model as a finished unit; it is not really intended to be rolled back into CAD programs for additional design changes.

STL files can be edited, but just like re-modeling a component from scratch, it can be a tricky process for those who don’t live and breathe this stuff. I’ll describe a few common issues related to STLs that can hold up getting that new project together, along with ways to deal with them. Thanks to 3D printing becoming much more commonplace, basic tools are within reach of even the least CAD-aware among us.

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Parametric Hinges with Tinkercad

Simple tools are great, but sometimes it is most convenient to just use something easy, and since it gets the work done, you don’t try out some of the other features. Tinkercad is a great example of that kind of program. It is actually quite powerful, but many people just use it in the simplest way possible. [Chuck] noticed a video about making a 3D-printed hinge using Tinkercad and in that video [Nerys] manually placed a bunch of hinges using cut and paste along with the arrow keys for positioning. While it worked, it wasn’t the most elegant way to do it, so [Chuck] made a video showing how to do it parametrically. You can see that video below, along with the original hinge video.

There are really two major techniques [Chuck] shows. First, he adds the necessary pieces to create the hinges to the Tinkercad toolbox. That makes it really simple to add them to any of your future designs. Second, he uses a combination of numeric parameters and duplication to quickly and precisely place the hinge components across another object — in this case a Batman logo.

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Customize All the Fan Covers You Never Knew You Needed

Do you need a fancy fan cover with precisely specified attributes, but have no desire to design one from scratch? If you answered yes (or no) then [mightynozzle] has the answer. The Customizable Fan Grill Cover is a parametric design in OpenSCAD that allows adjusting the frame style, size, and grill pattern for any fan cover one may possibly need. [mightynozzle] also went the extra mile to provide a large number of pre-made STL files for a variety of designs in a wide range of sizes, so those who don’t want to fuss with customizing can simply download and print.

Normally Thingiverse would allow customizing this model’s attributes with their built-in Customizer, but the functionality and availability of that feature is spotty. Luckily it’s always an option to download the source and do the customizing directly in OpenSCAD. For those who may be intrigued but are not sure where to start, here’s a reminder that we covered how to make a thing with OpenSCAD that demonstrates the whole process.

A True 3D Printed Weather Station

If the term “3D printed weather station” makes you think of a printed enclosure for off-the-shelf sensors, don’t feel bad. We thought the same thing when we first read the message [Rob Ward] sent in about his latest project. Surely he couldn’t mean that he actually printed all the principal parts of a serious weather station setup, such as the wind vane, anemometer, or rain gauge?

Except, on closer inspection, that’s exactly what he did. Every part of the weather station is designed in OpenSCAD, printed out, and infused with various vitamins to turn them into functional pieces of hardware. Interestingly enough, most of the magic is done with simple reed switches and magnets.

For example, the wind vane uses eight reed switches and an embedded magnet to communicate the current wind direction to the Arduino Uno which handles the user interface. Wind speed, on the other hand, it done with a single reed switch as it just needs to count rotations to calculate speed.

[Rob] did “cheat” by using an off-the-shelf barometric pressure sensor, but we’ll give him a pass for that one. Unless somebody wants to hit the tip line with a design for a printable barometer, we’ll consider this the high water mark in printable weather stations.

This isn’t the first time we’ve seen a DIY anemometer or rain gauge, of varying degrees of complexity. But the clean look of the final version, completely open nature of the OpenSCAD source, and the low part count make this an extremely compelling option for anyone looking to up their home forecasting game.