Mintomat: An Overcomplicated Gumball Machine

How do you get teenagers interested in science, technology, and engineering? [Erich]’s team at the Lucerne University of Applied Sciences makes them operate three robots to get a gumball. The entire demonstration was whipped together in a few days, and has been field-repaired at least once; a green-wire fix was a little heavy on the solder and would short out to a neighboring trace when mechanical force was applied.

Continue reading “Mintomat: An Overcomplicated Gumball Machine”

Portable Classroom Upgrade: Smaller, Cheaper, Faster

[Eric] at MkMe Lab has a dream: to build a cheap, portable system that provides the electronic infrastructure needed to educate kids anywhere in the world. He’s been working on the system for quite a while, and has recently managed to shrink the suitcase-sized system down to a cheaper, smaller form-factor.

The last time we discussed [Eric]’s EduCase project was as part of his Hackaday Prize 2016 entry. There was a lot of skepticism from our readers on the goals of the project, but whatever you think of [Eric]’s motivation, the fact remains that the build is pretty cool. The previous version of the EduCase relied on a Ku-band downlink to receive content from Outernet, and as such needed to stuff a large antenna into the box. That dictated a case in the carry-on luggage size range. The current EduCase is a much slimmed-down affair that relies on an L-band link from the Inmarsat satellites, with a much smaller patch antenna. A low-noise amp and SDR receiver complete the downlink, and a Raspberry Pi provides the UI. [Eric]’s build is just a prototype at this point, but we’re looking forward to seeing everything stuffed into that small Pelican case.

Yes, Outernet is curated content, and so it’s not at all the same experience as the web. But for the right use case, this little package might just do the job. And with a BOM that rings up at $100, the price is right for experimenting.

Continue reading “Portable Classroom Upgrade: Smaller, Cheaper, Faster”

Germans React to UK’s micro:bit

Getting kids interested in programming is all the rage right now, and the UK is certainly taking pole position with its BBC micro:bit, just recently distributed to every seventh-grader in the land. Germany, proud of its education system and technological prowess, is caught playing catch-up. Until now.

The Calliope Mini (translated here) is essentially a micro:bit clone, but one that has learned from the experience of its spiritual forefather — the connection points are spread around the outside of the board where the crocodile clips won’t accidentally touch each other.

Not content to simply copy, the Calliope also adds additional functionality. A microphone and speaker are integrated onboard, as is a Grove-style I2C connector. They’ve even added a TI DRV8837 H-bridge motor driver, so students could make a rolling robot straight out of the box.

Continue reading “Germans React to UK’s micro:bit”

Books You Should Read: Engineer to Win By Carroll Smith

One problem with engineering education today is a lack of experimental teaching. Oh sure you may have a project or two, but it’s not the focus of the program because it’s hard to standardize a test around. Typically sections of the field are taught in a highly focused theoretical course by a professor or graduate student with a specialization in that section. Because classes treat individual subject areas, it’s entirely possible to get a really good understanding of two pieces of the same puzzle, but never realize that they fit together to make a picture. It’s only when a freshly minted engineer gets out into the real world that they start to make the connections between seemingly disparate fields of knowledge.

This is why Carroll Smith’s book “Engineer to Win” is so good. He spent a lifetime as a practicing engineer in a field where a small failure could mean the death of a friend. So when he set out to write a book, he wrote a book that related everything needed to properly conceptualize and solve the mechanical engineering problems in his field.

One warning though; the book is not for the faint of heart. If you want to learn something difficult well, then this is book for you. Carroll skips the comforting analogies and gives the information exactly. It can get a little dense, but he makes the assumption that the reader is there to learn and, most importantly, understand. This takes work.

2016-08-01_02h06_34For example, you can’t really understand why a rolled bolt is stronger than a bolt cut on a screw machine until you understand how metal works on a crystalline level. The same goes for metal fatigue, brittle fractures, ductile failures, and all the maladies that metal can suffer. The difference between an engineer and a technician is this deep understanding. Otherwise the equations learned are just parts in a toolbox and not paint on an artist’s palette.

This is why the first half of the book is dominated by all things metallurgical. The book starts with the simple abstractions of the crystalline structures of metal. Unlike my materials class in university, it maintains a practical bend to the presentation of the information throughout the whole process. For example, it moves on to what all this practically means for metals undergoing stresses and failures before it launches into a (short) digression on how metals are made and their history.

However, if racecar plumbing is your thing his treastise, "Carroll Smith's Nuts, Bolts, Fasteners and Plumbing Handbook" is also fantastic.
However, if racecar plumbing and fasteners are kinda your thing, “Carroll Smith’s Nuts, Bolts, Fasteners and Plumbing Handbook” is also a fantastic read.

This first half of the book touches on non-ferrous metals and their proper use as well. After that comes some of the best explanations of metal fatigue, fasteners, and metal bonding I’ve ever read. When the failure of a joint causes a mechanism to fail in a toaster that’s one thing, but when it fails in a racecar people get hurt. Carroll is very exacting in what constitutes a forgivable oversight in engineering, and what does not.

Once the book has finished conveying a working understanding of metals and fasteners it seems to fracture into a pot-luck of different racecar-related topics. During my first reading of the book I resisted this strange turn of events. For example, I didn’t really want to read about racecar plumbing in the eighties, or what kind of springs and aerofoils Carroll likes. However, when I reread those sections in a more focused manner, I realized that many of them were teaching the practical application of the knowledge learned in the previous chapters. How does the metal make a good spring? Why is one kind of plumbing better than another?

Importantly, the anecdotes at the end of the book impart an understanding of the importance of professionalism in engineering. What is the true responsibility of an engineer? He teaches not to take the trust others place in your skills for granted. He teaches to trust in the skills of others. The book teaches humility as an engineer. He shows the kind of person one can become after a lifetime of earnest study in their craft.

Thanks to reader, [Dielectric], for recommending the book to me. Also, from the bit of research I’ve done, the older motorworks edition is generally considered to have better quality reproductions of the diagrams than the newer printings of the book.

Hackaday Prize Entry: Electronic, Visual Harmonicas

[sholnkin] is tasked with teaching a kindergarten class how to play a musical instrument. No, not those cheap plastic recorders. [shlonkin] is teaching kindergarteners how to play the only instrument that both blows and sucks: the harmonica.

Unlike a classroom of kids with plastic recorders, where the fingering is either right or it isn’t, [shlonkin] needs to teach kids to put their mouth over the right hole, and suck or blow to produce a note. The classroom has a poster laying out the notes on the harmonica, but they needed something better. [shlonkin] envisioned a large illuminated sign that lit up in different colors, and could play the displayed notes with a speaker.

The high-level design for this project includes a Teensy 3.2 with the Audio Adapter breakout driving a small audio amp. The Teensy also controls a bunch of LEDs mounted inside a wooden case. The layout of these LEDs went surprisingly well, and it’s rare to find a backlit panel that is lit this evenly.

As a classroom musical teaching aid, this type of device has been around for decades – deep in the recesses of band rooms in schools across the world, you can find old Wurlitzer pianos with devices that aren’t much different from this simple device. It’s a pedagogical method that worked back then, and should work now.

The HackadayPrize2016 is Sponsored by:

Multipurpose Robot For the Masses

As the cost of almost every technology comes falling down, from electronics to batteries to even tools like 3D printers, the cost to build things formerly out of reach of most of us becomes suddenly very affordable. At least, that’s what [John Choi] has found by building a completely DIY general purpose robot for around $2000.

OK, so $2000 isn’t exactly “cheap” but considering that something comparable (like Baxter) costs north of what a new car would cost means that [John] has dropped the price for a general-purpose robot by an order of magnitude. And this robot doesn’t skimp on features, either. It has a platform that allows it to navigate rooms, two manipulating limbs with plenty of servos, a laptop “head” that allows for easy interface, testing, and programming, and an Arduino Mega that allows it to interface with any sensors or other hardware with ease. It’s also modular so it can be repaired and transported easily, and it uses open source software and open hardware so it’s easy to build on.

This robot is an impressive piece of work that should help bring this technology to more than just high-end factories and research labs. They’ve already demonstrated the robot watering plants, playing the piano, picking things up, and many other tasks. We’d say that they’re well on their way to their goal of increasing the number of students and hobbyists who have access to this technology. If the $2k price tag is still too steep, though, there are other ways of getting into robotics without diving headfirst into a Baxter-like robot.

Continue reading “Multipurpose Robot For the Masses”

Hands-On With The BBC Micro:Bit

It’s been a long wait, but our latest single board computer for review is finally here! The BBC micro:bit, given free to every seventh-grade British child, has landed at Hackaday courtesy of a friend in the world of education. It’s been a year of false starts and delays for the project, but schools started receiving shipments just before the Easter holidays, pupils should begin lessons with them any time now, and you might even be able to buy one for yourself by the time this article goes to press.

The micro:bit top view
The micro:bit top view

It’s a rather odd proposition, to give an ARM based single board computer to coder-newbie children in the hope that they might learn something about how computers work, after all if you are used to other similar boards you might expect the learning curve involved to be rather steep. But the aim has been to position it as more of a toy than the kind of development board we might be used to, so it bears some investigation to see how much of a success that has been.

Opening the package, the micro:bit kit is rather minimalist. The board itself, a short USB lead, a battery box and a pair of AAA cells, an instruction leaflet, and the board itself.  Everything is child-sized, the micro:bit is a curved-corner PCB about 50mm by 40mm. The top of the board has a 5 by 5 square LED matrix and a pair of tactile switches, while the bottom has the surface-mount processor and other components, the micro-USB and power connectors, and a reset button. Along the bottom edge of the board is a multi-way card-edge connector for the I/O lines with an ENIG finish. On the card edge connector several contacts are brought out to wide pads for crocodile clips with through-plated holes to take 4mm banana plugs, these are the ground and 3V power lines, and 3 of the I/O lines.

Continue reading “Hands-On With The BBC Micro:Bit”