Lego Avengers Assemble to the Helicarrier!

The massive engineering-defying Helicarrier from the Avengers is a brilliant work of CGI. Too bad it’d never actually fly… Like… Never.

Luckily, that didn’t stop our favorite RC hackers over at FliteTest from making a scale model of it — that actually works! If you’re not familiar, the Helicarrier is a fictional ship, the pride of S.H.I.E.L.D’s air force, or is it their navy.

It’s a massive aircraft carrier with four huge repulsor engines built into it, borrowing tech from Stark Industries. The shear size of it is what makes it completely ridiculous, but at the same time, it’s also unbelievably awesome.

Unfortunately, repulsor technology doesn’t seem to exist yet, so the FliteTest crew had to settle with a set of 8 brushless outrunner motors, with two per “engine”. The whole thing is almost 6′ long.

It doesn’t handle that well (not surprising!) but they were able to launch another RC  plane off of it, mid-flight! Landing however… well you’ll have to watch the video. Continue reading “Lego Avengers Assemble to the Helicarrier!”

BLDC Controller With The Teensy 3.1

[Will] is on the electric vehicle team at Duke, and this year they’re trying to finally beat a high school team. This year they’re going all out with a monocoque carbon fiber body, and since [Will] is on the electronics team, he’s trying his best by building a new brushless DC motor controller.

Last year, a rule change required the Duke team to build a custom controller, and this time around they’re refining their earlier controller by making it smaller and putting a more beginner-friendly microcontroller on board. Last years used an STM32, but this time around they’re using a Teensy 3.1. The driver itself is a TI DRV8301, a somewhat magical 3 phase 2A gate driver.

The most efficient strategy of driving a motor is to pulse the throttle a little bit and coast the rest of the time. It’s the strategy most of the other teams in the competition use, but this driver is over-engineered by a large margin. [Will] put up a video of the motor controller in action, you can check that out below.

Continue reading “BLDC Controller With The Teensy 3.1”

MagnID – Sneaky New Way of Interacting With Tablets

New magnetic tech dubbed “MagnID” is being presented this weekend at Stanford’s annual TEI conference. It is a clever hack aimed to hijack a tablet’s compass sensor and force it to recognize multiple objects. Here is a sneak peek at the possibilities of magnetic input for tablets.

Many tablets come with some sort of triaxial magnetic sensor but as [Andrea] and [Ian]’s demo shows, they are only capable of passing along the aggregate vector of all magnetic forces. If one had multiple magnetic objects, the sensor is not able to provide much useful information.

Their solution is a mix of software and hardware. Each object is given a magnet that rotates at a different known speed. This creates complex sinusoidal magnetic fields that can be mathematically isolated with bandpass filters. This also gives them distance to each object. The team added an Arduino with a magnetometer for reasons unexplained, perhaps the ones built into tablets are not sufficient?

The demo video below shows off what is under the hood and some new input mechanics for simple games, sketching, and a logo turtle. Their hope is that this opens the door to all manner of tangible devices.

Check out their demo at Standford’s 9th annual “Tangible, Embedded, Embodied Interaction” this January 15-19, 2015.

Continue reading “MagnID – Sneaky New Way of Interacting With Tablets”

Universal Active Filters: Part 1

Today I am experimenting with a single chip Universal Active Filter, in this case I made a small PCB for the UAF-42 from Texas Instruments. I chose this part in particular as it facilitates setting the filter frequency by changing just a pair of resistors and the somewhat critical values that are contained on the chip have been laser trimmed for accuracy. This type of active filter includes Operational Amplifiers to supply gain and it supports various configurations including simultaneous operating modes such as Band Pass, Low Pass and High Pass make it “Universal”.

Filter Basics

Speaker Crossover Example
Speaker Crossover Example

Looking at the block diagram you can see where I have inserted a dual-ganged potentiometer to change both resistors simultaneously which should allow a straight forward adjustment for our purposes here.

Looking into the components of a simple RC filter which can easily implement a simple Low Pass or High Pass filter, we see that the math is fairly straight forward and swapping the components with each other is all that is needed to change the type of filter. Continue reading “Universal Active Filters: Part 1”

Cheap DIY Microscope Sees Individual Atoms

This is not an artist’s rendering, nor a physics simulation. This device held together with hardware-store MDF and eyebolts and connected to a breadboard, is taking pictures of actual atomic structures using actual measurements. All via an 80¢ piezo buzzer? Madness.

Gold atoms in a crystal.

This apparent wizardry is called a scanning tunneling microscope which takes advantage of quantum tunneling. The device brings a needle atomically close to the object to be measured (by hand), applying a small voltage (+-15V), and stopping when it starts to conduct. Depending on the distance between the tip and the target, the voltage varies and does so precisely enough to identify whether an atom is underneath or not, and by how much.

The “pictures” are not photographs like a camera might take from a standard optical microscope, however they are neither guesses nor averages. They are representations of real physical measurements of specific individual atoms as they exist on the infinitesimal area being probed. It “sees” by measuring small voltage changes. Another difference lies in the “scanning.” The probe examines atoms the way one would draw ASCII images – single pixels at a time until an entire atom was drawn. Note that the resolution – as shown in the pictures – is sub-atomic. Sizes of atoms are apparent as are the distances between them. In this they are closer related to the far more expensive Scanning Electron Microscope technology, but are 10-100x zoomier; resolving 0.00000000001m, or 0.00000000039″.

Scan Head – Piezo cut into quadrants

One would presume that dealing with actual atoms requires precision machining vast orders of magnitude beyond the home hobbyist but, no. Any one of us could make this at home or in our hackerspaces, for nearly free. Apparently even sharpening a tip to a single atom is, as [Dan] says “not as hard to achieve as you might think!” You take some tungsten wire and pull on it as you cut so that it shatters diagonally. There are better ways he suggests, but that method is good enough.

The ordinary piezo buzzer that is key to the measurement is chopped into quadrants with an ordinary X-Acto knife by hand. Carefully, because it is fragile, but, nothing more to it than that. There are two better and common methods but they cost hundreds of dollars, not 80 cents. It should be carefully glued since soldering heat will damage it, but, [Dan] soldered his anyway because it was easier. Continue reading “Cheap DIY Microscope Sees Individual Atoms”

Jamming Robot will Destroy You at Beer Pong

DSC_0363Wandering the aisles of Eureka Park, the startup area of the Consumer Electronics Show, I spotted a mob of people and sauntered over to see what the excitement was all about. Peeking over this gentleman’s shoulder I realized he was getting spanked at Beer Pong… by a robot!

Those in the know will recognize that the bot has only 3 cups left and so the guy definitely was giving it run for its money. But the bot’s ability to swish the ball on nearly every throw accounts for the scoreboard which read Robot: 116, Humans: 11. Unlike the ping pong robot hoax from last March, we can vouch for this one being real!

If you’re trying to attract the geek demographic, this must be one of the best offerings ever shown at a trade show. Empire Robotics manufactures the VERSABALL gripper. We know this as a jamming gripper and have been looking at the tech progress for many years now. Looking back to this Cornell research video from 2010 we realize it is based on the white paper which [John Amend, PhD] co-authored. He’s now CTO and Co-Founder of the company and was one of the people running the booth. We love it when trade show booths are staffed by the engineers!

Join me after the break for a rundown of how the system works along with a video clip of it hitting the target.

Continue reading “Jamming Robot will Destroy You at Beer Pong”