A Very, Very Small IMU

May 20, 2015 by Brian Benchoff 18 Comments

The reason we’re playing with quadcopters, flight controllers, motion controlled toys, and hundreds of other doodads is the MEMS revolution. A lot is possible with tiny accelerometers and gyroscopes, and this is looking like the smallest IMU yet. It’s an 18mm diameter IMU, with RF networking, C/C++ libraries, and a 48MHz ARM microcontroller – perfect for the smallest, most capable quadcopter we’ve ever seen.

The build started off as an extension of the IMUduino, an extremely small rectangular board that’s based on the ATMega32u4. While the IMUduino would be great for tracking position and orientation over Bluetooth, it’s still 4cm small. The Femtoduino cuts this down to an 18mm circle, just about the right size to stuff in a model rocket or plane.

Right now, femtoIO is running a very reasonable Kickstarter for the beta editions of these boards with a $500 goal. The boards themselves are a little pricey, but that’s what you get with 9-DOF IMUs and altimeter/temperature sensors.

[Sophi Kravitz] On Ask An Engineer Tonight

May 19, 2015 by Mike Szczys 9 Comments

Whew, your Wednesday night entertainment is all sorted out. Mark it in your calendar, [Sophi Kravitz] will be appearing on Adafruit’s Ask an Engineer at 8pm EDT (UTC -4).

Of course she’ll be talking about The Hackaday Prize with all of the incredible entries so far and the amazing opportunities waiting for you as THP continues through the summer. But [Sophi’s] life experience runs far-and-deep and so will the conversation. She is an Electronics Engineer, an Artist, and a huge part of the Hackaday crew. This year she landed a grant to bring one of her projects to life for Burning Man (and to document the process which we’re really excited about). She’s brewing up a new project involving Quadcopters and the technology [Alan Yates] has been working on for Valve. And [Sophi] frequently works on projects like Breathe that delight us with her creativity.

But hey, we better leave some of it for the show. The live link is above, here’s the Adafruit page as well.

Continue reading “[Sophi Kravitz] On Ask An Engineer Tonight” →

Hackaday Prize Entry: Density Altitude Gauge

May 18, 2015 by Brian Benchoff 16 Comments

Despite what extraordinarily overpowered quadcopters suggest, the air pressure of whatever a flying machine flys at is extremely important. Pressure is dependent on altitude and temperature, and there are hundreds of NTSB investigations that have concluded density altitude – pressure altitude corrected for nonstandard temperature variations – was the reason for a crash. Normally density altitude is computed through a slide rule or a flight computer, with the pilot entering in altitude and temperature, but somehow accidents still happen. For his entry to The Hackaday Prize, [Neil McNeight] is building an automated density altitude calculator to automate the process entirely.

Instead of having a pilot enter the altitude and temperature into a flight computer manually, [Neil]’s device grabs the current altitude from a GPS unit, and reads the temperature with a tiny sensor acquired from SparkFun. With just a little bit of math, this device will spit out the altitude an airplane or ‘copter thinks it’s at.

While the FAA won’t allow instruments that are cobbled together on a breadboard, this does have a few applications in the RC world. There are extremely high performance racing quadcopters out there now, and knowing how the craft will perform before flying it will save a few props.

The 2015 Hackaday Prize is sponsored by:

Transmitting HD Video From A Raspberry Pi

March 28, 2015 by Brian Benchoff 30 Comments

It’s been a few years since the RTL-SDR TV Tuner dongle blew up the world of amateur radio; it’s a simple device that listens in on digital television frequencies, but it’s one of those tools that’s just capable enough to have a lot of fun. Now, we have a transmitting dongle. It’s only being used to transmit live HDTV from a Pi, but that in itself is very interesting and opens up a lot of possible builds.

The key piece of hardware for this build is a UT-100C DVB-T modulator. It’s a $169 USB dongle capable of transmitting between 1200-1350 MHz, and with a special edition of OpenCaster it’s possible to transmit over-the-air TV. There’s no amplifier, so you won’t be sending TV very far, but it does work.

On the Raspberry Pi side of the build, the standard camera captures H.264 video with raspivid, which is converted to a DVB compliant stream using ffmpeg. These are well-worn bits of software in the Raspberry Pi world, and OpenCaster takes care of the rest.

While this seems like the perfect solution to completely overbuilt quadcopters, keep in mind transmitting on the 23cm band does require a license. Transmitting in the UHF TV bands is a bad idea.

Switchable Magnet With A Simple Circuit

March 17, 2015 by James Hobson 26 Comments

Magnets are awesome. Electromagnets are even cooler. But what if you could make a semi-permanent switchable magnet that acts like an electromagnet, but doesn’t use any energy to hold metal? You’re going to want to take a look at this Low-power Magnetic Hold and Release Mechanism.

It’s actually a very simple concept. It is basically an electromagnet attached to a permanent magnet — it’ll hold any metal object exactly as you’d expect — but if you run current through the inductor attached to it, the magnetic field created by the electricity will temporarily cancel out the field of the magnet — thus freeing your object being held. Since gravity is pretty fast acting, this impulse of current doesn’t need to be very long, only fractions of a second.

Now the real question is how big could you go? We covered another project a while ago called Open Grab which discusses the possibility of using technology like this in Quadcopters.

For a solution that uses no power at all take a look at switchable magnet clamps used for welding — they’re pretty cool — but patent protected of course.

2015 THP Inspiration: The Environment

March 10, 2015 by Brian Benchoff No comments

It’s not as flashy as Tesla coils or electric vehicles going 200 mph, but the environment is more important than a bunch of cool baubles and sparks flying everywhere. When it comes to this year’s Hackaday Prize, you’re going to need a project that matters, and what’s a better way to do it than with something to help the environment?

While not traditionally a domain that rocks people’s socks, there are a lot of cool builds that can help the environment like this hyperspectral imager that’s a mashup of a spectrometer and a camera, or something that takes an image of an object, complete with the spectral data of each pixel. It’s useful for everything from farming, to forestry, to medicine.

Perhaps you want to get your hands messy by mucking about in the dirt. You’ll probably find something interesting to build for this year’s Hackaday Prize, like the modular farmer’s market we saw in Detroit last year. How about an urban farming and aquaponics setup? Tilapia do well in giant buckets, you know.

If robots are more your speed, then how about an RC tractor or an entire robotic farm? You could always eradicate invasive plants with a quadcopter if flying around is more suited to your expertise. There are plenty of ways to do something that matters for this year’s Hackaday prize, but we’d be lying if we had all the answers. That’s where you come in with your entry for The Hackaday Prize.

2015 THP Inspiration: Medical Hacks

March 10, 2015 by Brian Benchoff 6 Comments

Last year’s Hackaday Prize focused on building something cool, useful, and open. This led to builds as impressive as quadcopters nicknamed the Decapitron, to devices as useful as an Everything Radio. It’s a big field, and if you want to build something that will win, you first need an idea.

This year we’re making that part of the process a little easier for you. We’re looking for builds that matter, be they devices that monitor pollution, feed entire populations, lay the groundwork for powering an entire city, or reduce the cost and increase access to medical care.

Medical builds are a tricky subject, but over the years we’ve seen a few that stand out. Some can be as simple as a pill dispenser that tells the Internet when you don’t take your meds. This type of build is actually pretty popular with several iterations, one that works with pill bottles.

Maybe a gadget you could find in a drug store isn’t your thing. That’s okay, instead you can turn your attention to advanced medical imaging, like 3D printing a brain tumor and preventing a misdiagnosis. We’ve seen 3D printed MRI and CT scans for a while now, and coming up with a system that automates the process would be a great entry for the Hackaday prize.

Of course with 3D printers, you have a bunch of prosthesis applications; from a nine-year-old who designed his own prosthetic arm, a printed prosthetic arm for a stranger, or something simpler like our own [Bil Herd]’s quest to rebuild a finger.

These are all simple builds, but ones that clearly meet the criteria of doing something meaningful. The sky is the limit, and if you want to improve the desktop CT scanner, learn CPR (correctly) from an automated assistant, or be brought back to life with your own design, that’s all well within the goals of this year’s Hackaday Prize.