Posts Tagged ‘hackaday’

h1

I’ve got an IMU in my pocket and it wants out

December 23, 2014

I have this idea for another ring…

I ordered an Adafruit 9-DOF IMU board for a client who went on holiday vacation before signing the contract so now I’ve got this board burning a hole in my pocket. Given how much I spent at their site, Adafruit sent along a free Trinket board. At the same time, I was starting slides for a presentation entitled “Introduction to Inertial” and working out scheduling details to have ThingM’s Tod Kurt on our Embedded podcast. Combine all these things and what do you get?

One thing you don’t get is something that will easily fit on a ring. Still, if it could, what would I want it to do? Maybe I’ll even get boards made…

The idea stemmed from a magnetometer first. I’ve read about anklets with several cell-phone motors and a magnetometer that subtly teaches you which way is north. I’d love a little ring that glowed white when I was facing north, red when west, and green for east. It would be dark for south. It would be a neat little beacon.

Never mind that the almost-always-on LED will drain a battery fairly quickly so ring mounted will need to be easily rechargeable. Never mind that I’ll need an accelerometer to tilt compensate the magnetometer (oh! must add why to the presentation!). Of course, adding an accel does give me a way to turn it off and on.

Well, if I’m to make the ring, I need to write the code. Hardware is not my forte but if I get it working well, I can probably get help laying out an ATtiny and a magnetometer/accelerometer chip. Though, as long as I’ve got a whole IMU to play with, I might as well use it all.

I spent a few days stripping the Adafruit sensor code of anything I considered unnecessary (floating point? gone! functions that make the sensors interface generic? gone!) so it would fit on the ATtiny in the Trinket (5000 bytes of code space! whee!). And then I wised up and realized I was going to spend all my time making atan2 tables, I should do the prototype on a regular Arduino.

It is funny how 32k feels HUGE and the ATmega is blazingly fast compared to the ATtiny. I stopped rewriting the Adafruit code and started writing the code I wanted. This was a good decision as it gives me more time to play (and since that’s what this is for me, making it seem like work was a good way to get frustrated and move on to another, more fun project).

I think the accelerometer mode should be the simplest. It should glow red if gravity is felt in the X direction (positive or negative), green if Y, blue if Z. This would let me talk about how accelerometers are used as gravity sensors the majority of the time. While free fall detection and actual acceleration are interesting, mostly we want our devices to know which way is down. (Since I’ll use double taps to move between accel, gyro, mag, and off modes, discussing gestures will be natural.)

For the gyro mode, the LED will light proportionally to how fast the rate sensors see movement. This will go nicely with my notes about how rate sensors are only useful when things are moving.

The mag mode will be the North Star implementation I described before.

I started out wanting a ring on a Trinket. Now I want a multi feature demo tool in a box.

(Note: I cross posted this project log from a new Hackaday project. I’ll be putting build details over there as I get it working. I’ll probably post here when I write less technical stuff.)

Posted in Uncategorized | Tagged , , , | Comments Off on I’ve got an IMU in my pocket and it wants out

h1

Why this should win the Hackaday Prize…

November 11, 2014

I was a judge for the Hackaday Prize. The contest was to build something awesome (and connected). The first prize was a trip to space (or the ~$200k they thought it would cost). All of the top five finalist rewards were pretty incredible.

I judged the 50 semi-finalists, scoring them on openness, wow factor, connectedness, reproducibility, innovation, and user experience. Once we had the top five, they got another month to work on their projects and we re-judged, adding manufacturability to the judging criteria.

It was hard. While I thought all of the top five belonged, there were many of the top 50 that could so easily have been in the top five. Now that Hackaday is about to announce the prize winner, let me advocate for which one(s) I think should win, in no particular order.

SatNOGS aims to build a global network of ground stations to listen to satellites. Their new finalist video was great, a perfect introduction to the problem (and the team). And this, unlike the other finalists, was a clearly team effort: a huge project with lots of parts to it (hardware, mechanical, embedded software, servers, UIs).  Still, the application to readers was nontrivial: in my backyard, I could build one of their widgets and help people around the world listen to the satellites.

Enabling technologies are tough to make appealing. It is easy to fall into the lure of a personal satellite (e.g., cubesat) but listening requires more infrastructure than most non-governments have access to. This is exactly the sort of problem that needs to be crowdsourced. The SatNOGS team made it easy for people to join. Their fantastic documentation leaves lots of options for building; it is a good instruction set that still lets me customize to my particular interests (and parts available). It would be fun to build this with a middle or high school student to get them interested in space technology. Between their excellent build instruction, good use of other open source components, and their topic (space-oriented so therefore prize-related), SatNOGS should win.

In the RamanPi project, the creator makes a spectrometer. OMG, you guys, I have ALWAYS wanted a spectrometer!!!!! (This is a total OMG Ponies! moment.) What’s even better, after reading the documentation, I feel like I could build one. Before Christmas. I could have my own little gadget to tell me what things are made of. I could take it with me and explore the water components around the bay or the soil composition. I could be a SCIENTIST.

Err… sorry, where was I? Ahh, right RamanPi. Not only was RamanPi a great item to build, the way the creator did it was great. Being new to the area, the project logs show the real sort of two steps forward, one step back that is a part of engineering we hide too often. Even better, the use of 3D printing to avoid expensive optical benches is something I’m going to be using myself. I like that the home 3D printer is being put to use to create this level of awesomeness. This project was all about what is possible and kindles the desire to explore: RamanPi should win.

The PortableSDR project is a software defined radio. It is small (truly portable) and has a well thought out display (aka I loved the waterfall display). I very much want a kit of this. Though I may use it as a portable spectrum analyzer instead of a way to listen to all of the radio bands at once.

While the tech on PortableSDR was neat, what I liked most was teh humanness of the creator. While the finalist and semifinalist videos were clean (I liked that the finalist video was outside, where the PortableSDR is likely to live), there was at least one video with a messy bench and cartoons running in the background (I suspect a kidlet). This was a person who had an idea, who put it on Hackaday because it was neat. Now he’s a finalist and people want kits and finished products. I don’t know what he meant to do next in his career but he’s probably changed the course of his life by following through on his idea. I want to see what happens next. PortableSDR shows the best side of Hackaday: follow your dreams and the rest will follow. PortableSDR should win.

The ChipWhisperer project is one I keep sending to all of my hardware friends and saying, “see! look!” The project uses power analysis to crack software security in chips… which is to say that this gadget breaks most of the security on most of the devices we all use right now. It is terrifying. On the other hand, these sorts of tools already existed, they just cost a lot. Now it is cheap ($1500 for the prebuilt kit, as low as $100 for DIY pieces) but we were never safe in the “secure because math” mindset.  While this makes my job more difficult, it will make everything better in the long term.

Even as scary and important as this project is, there were many other things going for it. It takes a complicated topic and makes it sound easy and interesting.  Many people want to know where to get started with FPGAs. This is a great project for that. It would be hard to do this power analysis in a microprocessor or single board computer. This is a good use of FPGA to solve a non-contrived problem. It would be useful to read the code (which was well written, at least the stuff I looked at). There are lots of pieces here: desktop software, the embedded, hardware, and FPGAs. I’m impressed that he didn’t stick to his hardware, he talked about how to reproduce with other kits. Hackaday has traditionally been about breaking things open to see how they worked. ChipWhisperer takes that ethos and puts a rocket behind it; ChipWhisperer should win.

The Arducorder is an “open source science tricorder”. I think the most important thing in there is “science” though I could see it doing a smackdown with “tricorder”. The author took a lovely display and a tiny Arduino based board, added a dozen (seriously) sensors. I truly want one of these.

Let me pause here to say that I don’t think I’ll be going to Mars. This makes me sad. I don’t even think I’ll get to the moon. I can only hope that someone in my future goes to at least one of these places. But unless we stop teaching kids that science means boring memorization, no one is going to go. Space will become a cold, dark, empty wasteland.

Back to Arducorder… by having a charming display, easily extensible software, and all of these neat sensors, it lets people walk around saying, “how is this different than that?” It fosters curiosity and reminds us that science is about discovery. Talking about gravity as acceleration is a lot more fun when you can see the data. Arducorder enables science education in a way that is just brilliant: Arducorder should win.

 

Posted in Uncategorized | Tagged , , , | 5 Comments »