That TRS Jack On Your Graphing Calculator Does More Than You Think

September 25, 2018 by 28 Comments

It’s not Apple IIs, and it’s not Raspberry Pis. The most important computing platform for teaching kids programming is the Texas Instruments graphing calculator. These things have been around in one form or another for almost three decades, and for a lot of budding hackers out there, this was the first computer they owned and had complete access to.

As hacking graphing calculators is a favorite for Maker Faires, we were pleased to see Cemetech make it out to this year’s World Maker Faire in New York last weekend. They’re the main driving force behind turning these pocket computers with truly terrible displays into usable computing platforms.

As you would expect from any booth, Cemetech brought out the goods demonstrating exactly what a graphing calculator can do. The most impressive, at least from a soldering standpoint, is their LED cube controlled by a graphing calculator. The electronics are simple, and just a few 595s and transistors, but this LED cube is taking serial data directly from the link cable on a graphing calculator. Of course, the PCB for the LED cube is designed as an Arduino shield for ease of prototyping, but make no mistake: this is an LED cube controlled by a calculator.

If you can send serial data to a shift register from a graphing calculator, that means you can send serial data to anything, bringing us to Cemetech’s next great build featured this year. It’s an N-gauge model train, with complete control over the locomotive.

There’s a lot more to controlling model trains these days than simply connecting a big ‘ol variac to the tracks. This setup uses Direct Cab Control (DCC), a system that modulates commands for locomotives while still providing 12-15V to the tracks. There’s a good Arduino library, and when you have that, you can easily port it to a graphing calculator.

Cemetech is one of the perennial favorites at Maker Faire, and over the years we’ve seen everything from the Ultimate TI-83+ sporting an RGB backlight and a PS/2 port to a game of graphing calculator Whac-A-Mole. It’s all a great example of what you can do with the programmable computer every 90s kid had, and an introduction to computer programming education, something Cemetech is really pushing out there with some hard work.

Box Forts For Adults: Best Practices And Design Strategies

September 24, 2018 by 33 Comments

Many a grown up can reminisce about building various architectural wonders in their youth. Forts, whether based on boxes or blankets, were the order of the day, and an excellent way to spend a rainy Sunday afternoon.

It just so happens that there is no law against scaling up such activities once one has reached the age of majority. However, to build a structure at this level takes some careful planning and consideration, and that is the purpose of our article here today.

Location, Location, Location

To avoid an awkward conflict, be sure to warn your housemates of impending construction well ahead of time.

The first major consideration when starting your build should be the area in which you wish to do it. Building inside has the advantage of avoiding the weather, however hard floors can lead to sore knees when crawling around. Additionally, you’re a grown up now, so it’s less likely your peers will be impressed to hear you sat inside a box in your living room.

No, if you’re going to do this right, you’ll want to go outside. A nice flat lawn is best, providing soft ground and plenty of space. The challenges of the elements will guide your work – sitting inside your cardboard home feels all the more satisfying when you’re cosy and dry as you listen to the patter of rain on the roof. There’s a real sense of accomplishment when you’ve built something that can survive the harsh outdoors, and besides, the views are better, too. Continue reading “Box Forts For Adults: Best Practices And Design Strategies” →

Space Garbage Truck Passes Its First Test

September 20, 2018 by 54 Comments

Back in April we reported on the successful launch of the SpaceX Falcon 9 rocket to the International Space Station which carried, along with supplies and experiments for the orbiting outpost, the RemoveDEBRIS spacecraft. Developed by the University of Surrey, RemoveDEBRIS was designed as the world’s first practical demonstration of what’s known as Active Debris Removal (ADR) technology. It included not only a number of different technologies for ensnaring nearby objects, it even brought along deployable targets to use them on.

Orbital debris (often referred to simply as “space junk”) is a serious threat to all space-faring nations, and has become even more pressing of a concern as the cost of orbital launches have dropped precipitously over the last few years, accelerating number and frequency of new objects entering orbit. The results of these first of their kind tests have therefore been hotly anticipated, as the technology to actively remove debris from Low Earth orbit (LEO) is seen by many in the industry to be a key element of expanding access to space for commercial purposes.

Six months after its arrival in space we’ve now starting to see the first results of the groundbreaking tests performed by the RemoveDEBRIS spacecraft, and so far it’s very promising.

Continue reading “Space Garbage Truck Passes Its First Test” →

Learn To Loop The Python Way: Iterators And Generators Explained

September 19, 2018 by 17 Comments

If you’ve ever written any Python at all, the chances are you’ve used iterators without even realising it. Writing your own and using them in your programs can provide significant performance improvements, particularly when handling large datasets or running in an environment with limited resources. They can also make your code more elegant and give you “Pythonic” bragging rights.

Here we’ll walk through the details and show you how to roll your own, illustrating along the way just why they’re useful.

Continue reading “Learn To Loop The Python Way: Iterators And Generators Explained” →

The Tiny, Pocket-Sized Robot Meant For Hacking

September 15, 2018 by 7 Comments

The world is full of educational robots for STEAM education, but we haven’t seen one as small or as cute as the Skoobot, an entry in this year’s Hackaday Prize. It’s barely bigger than an inch cubed, but it’s still packed with motors, a battery, sensors, and a microcontroller powerful enough to become a pocket-sized sumo robot.

The hardware inside each Skoobot is small, but powerful. The main microcontroller is a Nordic nRF52832, giving this robot an ARM Cortex-M4F brain and Bluetooth. The sensors include a VL6180X time of flight sensor that has a range of about 100mm. Skoobot also includes a light sensor for all your robotic photovoring needs. Other than that, the Skoobot is just about what you would expect, with a serial port, a buzzer, and some tiny wheels mounted in a plastic frame.

The idea behind the Skoobot is to bring robotics to the classroom, introducing kids to fighting/sumo robots, while still being small, cheap, and cute. To that end, the Skoobot is completely controllable via Bluetooth so anyone with a phone, a Pi, or any other hardware can make this robot move, turn, chase after light, or sync multiple Skoobots together for a choreographed dance.

While the Skoobot is an entry for this year’s Hackaday Prize, the creator of the Skoobot, [Bill Weiler] is also making these available on Crowd Supply.

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One Small Step For A Space Elevator

September 14, 2018 by 149 Comments

Space elevators belong to that class of technology that we all want to see become a reality within our lifetimes, but deep-down doubt we’ll ever get to witness firsthand. Like cold fusion, or faster than light travel, we understand the principles that should make these concepts possible, but they’re so far beyond our technical understanding that they might as well be fantasy.

Except, maybe not. When Japan Aerospace Exploration Agency (JAXA) launches their seventh Kounotori H-II Transfer Vehicle towards the International Space Station, riding along with the experiments and supplies for the astronauts, will be a very special pair of CubeSats. They make up the world’s first practical test of space elevator technology, and with any luck, will be one of many small steps that precedes the giant leap which access to space at a fraction of the cost will be.

Of course, they won’t be testing a fully functional space elevator; even the most aggressive of timelines put us a few decades out from that. This will simply be a small scale test of some of the concepts that are central to building a space elevator, as we need to learn to crawl before we can walk. But even if we aren’t around to see the first practical space elevator make it to the top, at least we can say we were there on the ground floor.

Continue reading “One Small Step For A Space Elevator” →

Temperature Controlled Fan Keeps Printer Cool

September 11, 2018 by 15 Comments

There are many annoying issues associated with desktop 3D printers, but perhaps none are trickier than keeping the machine at the proper temperature. Too cold, and printed parts can warp or fail to adhere to the bed. Too hot, and the filament can get soft and jam, or the motors will start clanking and missing steps. High-end industrial 3D printers have temperature-controlled enclosures for precisely this reason, but the best you can hope for with a printer that’s little more than some aluminum extrusion and an Arduino is a heated bed that helps but is no substitute for the real thing.

Like many 3D printer owners chasing perfect prints, [Steve Thone] ended up putting his machine into a DIY enclosure to help keep it warm. Unfortunately, there gets to be a point when things get a little too hot inside the insulating cube. To address this issue, he put together a simple but very elegant temperature controlled fan to vent the enclosure when the internal conditions go above the optimal temperature.

[Steve] picked up the digital temperature controller on Amazon for about $4 USD, and found a 60 mm fan in the parts bin. He then came up with a clever two-part printed enclosure that slides together to make the fan and controller one unit which he can place in a hole he cut in the enclosure.

A lot of attention was paid to the front panel of the device, including mid-print filament swaps to create highlighted text and separate buttons printed in different colors. The end result is a very professional looking interface that involved relatively little manual labor; often a problem when trying to come up with nice looking panels.

Whether it’s to keep from breathing ABS fumes, or to quiet the thing down enough so you can get some sleep, it looks like an enclosure of some type is becoming the latest must-have 3D printer accessory.