Judge Spotlight: Limor “Ladyada” Fried

June 24, 2014 by 52 Comments

judge-spotlight-ladyada

We sent off a list of questions, just like every week, and [Ladyada] offered to do a video response. How awesome is that? Not only did she answer our questions, but she talked at length for several of them. We’re biased, but her explanation about Adafruit’s manufacturing processes and options for home hackers to get boards spun was a real treat.

Perhaps we should step back for a minute though. In case you don’t know [Limor Fried], aka [Ladyada], is a judge for The Hackaday Prize which will award a trip into space and hundreds of other prizes for hackers who build connected devices that use Open Design (Open Hardware and Open Source Software). She’s the founder of Adafruit Industries, an MIT double-grad, and all around an awesome engineer!

Check out the video after the break. We’ve included a list of the questions and the timestamps at which they are answered.

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The 200 LED Ring Clock

June 24, 2014 by 9 Comments

There are LED clocks, and then there are LED clocks that can blind you from 30 paces. [Stiggalicious’s] LED ring clock is of the latter variety. 200 WS2812B/Neopixel RGB LEDs drive the ring clock to pupil searing levels. The clock runs on ATMega1284P, with timekeeping handled by an NXP PCF8563 real-time clock chip. Code is written in Arduino’s wiring language using Adafruit’s Neopixel library.

Building the clock with a single Printed Circuit Board (PCB) would be both expensive and wasteful. [Stiggalicious] cleverly designed his clock to be built with 8 copies of the same PCB. Each board makes up a 45° pie slice of the ring. All 8 PCBs have footprints for the CPU, clock chip, and other various discrete parts, but only the “master” section has these parts populated. 7 “slave” sections simply pass clock, data, power and ground through each LED. He used Seeedstudio’s board service to get 10 copies of his PCB made, just in case there were any mistakes.

[Stiggalicious] rolled the dice by buying exactly the 200 LEDs he needed. Either he got really lucky, or the WS2812 quality testing has improved, because only one LED had a dead blue LED.

If you’d like to find out more, [Stiggalicious] gives plenty of details in his Reddit thread. He doesn’t have a webpage setup for the clock but he’s uploaded his source code (pastebin link) and Altium schematic/PCB files (mega.nz link). We may be a bit biased, but hackaday.io would be a perfect spot for this or any other project!

The State-Based Nixie Multimeter

June 24, 2014 by 29 Comments

state

Instead of numbers the IN-15A Nixie tube has symbols, specifically n, μ, P, -, +, m, M, k, Π, and %. The related IN-15B Nixie has letters: A, F, H, Hz, Ω, S, V, and W. These should look familiar to you. [kittan] decided it would be really cool to have a Nixie-equipped multimeter, and since he’s going retro fabulous anyway, he might as well make his multimeter controllerless, with discrete logic and comparator ICs. It’s a state-based Nixie multimeter, and it’s going to be freakin’ awesome.

The basic plan of the multimeter is a precision 1V voltage reference, a bunch of opamps, and a ton of resistors to form a ladder All the opamps in each decade are XOR’d together, so when one of the ten comparators for each decade stage is tripped, only one number will display on the (numeric) Nixie tube.

With a reasonable plan for measuring a voltage, it’s not too hard to expand the design for other measurements. V=IR, so with a constant current, V=R. The same equation can be used with a fixed resistance to determine current. Capacitance can be measured by comparing the change in charge of a known capacitor. Inductance, conductance, power, and frequency are all planned for this monster of a multimeter.

The initial PCB design is completed (and shown above) and it’s theoretically possible to do on a single-sided board with a minimum of jumpers. An amazing project, and even though you could probably find a similar, ancient meter in a trash heap or on a collector’s shelf, this is by far one of the best Nixie projects we’ve ever seen.

 

5000 Lumen LED Projector? Naw, How About A Whopping 1 Candela?

June 23, 2014 by 23 Comments

1 candle projector

One of our readers recently found a ASK Proxima C170 (also sold as the InFocus LP600) in the waste bin, thrown away because it stopped working — He snatched it up and decided to try tinkering with it. A visual inspection quickly found the problem, a 100uF cap had blown!

He replaced the capacitor and got the projector to turn on again without much difficulty. Not wanting to pay a few hundred dollars for a bulb he’s ordered a 5000lm 50W LED array from China to give it new life as an LED projector, because as it turns out it’s a fairly simple hack to trick the projector into thinking it has an official lamp in it. It’s just a matter of shorting a few leads on some of the photo-couplers!

In fact, once this hack is done, you can use any kind of light source you want! So just for kicks he decided to try using a tea light candle. It actually managed to project an image on the wall thanks to the optics of the projector! Functional? Not really, but it’s a cool way to prove a successful hack towards an even cooler end project though!

For other fun projector hacks, check out this roundup we did a few years ago.

[Thanks thefamoushat!]

Using Echoes Of Light To Turn Walls Into Mirrors

June 23, 2014 by 21 Comments

using a wall as a mirror

 

[Matthias] recently published a paper he worked on, in which he details how his group managed to reconstruct a hidden scene using a wall as a mirror in a reasonably priced manner. A modified time-of-flight camera (PMD CamBoard Nano) was used to precisely know when short bursts of light were coming back to its sensor. In the picture shown above the blue represents the camera’s field of view. The green box is the 1.5m*1.5m*2.0m scene of interest and we’re quite sure you already know that the source of illumination, a laser, is shown in red.

As you can guess, the main challenge in this experience was to figure out where the three-times reflected light hitting camera was coming from. As the laser needed to be synchronized with the camera’s exposure cycle it is very interesting to note that part of the challenge was to crack the latter open to sniff the correct signals. Illumination conditions have limited impact on their achieved tolerance of +-15cm.

Programming Pi Games With Bare Metal Assembly

June 23, 2014 by 21 Comments

pifoxWhile the most common use for a Raspberry Pi is probably a media center PC or retro game emulator, the Pi was designed as an educational computer meant to be an easy-to-use system in the hands of millions of students. Team 28 at Imperial College London certainly living up to the Raspberry Pi Foundation’s expectations with their bare metal assembly clone of Star Fox, aptly titled PiFox.

This isn’t the first time a college course has taken up the task of developing software for the Pi without an operating system; a few years ago, Cambridge University started that off with a series of bare metal tutorials for the Pi that included drawing graphics on the screen and playing around with USB keyboards. PiFox greatly expands on what those early tutorials could do, reading an NES joystick from the GPIO pins, sound with DMA, and rendering 3D objects.

If you’d like to build PiFox for yourself, or better yet, expand on the existing build, all the code is up on Github. There’s also a Raspberry Pi emulator for Linux, just in case you have an ARM assembly bug you just can’t scratch with a Raspberry Pi.

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Hackaday’s Wikipedia Page Needs Help

June 23, 2014 by 42 Comments

Wikipedia-logo-en-bigHey, did you know we have a Wikipedia page? We didn’t either. Until today you could search for “Hackaday” and nothing would come up. That’s because it’s listed as “Hack a Day” and it hadn’t seen any TLC in at least a couple of years.

Here’s the great thing about Wikipedia, they want factual information so they discourage people with Conflicts of Interest from editing the pages. That means that having the Hackaday Staff edit the page is a sticky issue. I did indeed edit the page in order to add more sections (History, Hackaday Projects, Accolades) to make it easier for the community to work on the article. I disclosed this in the “Talk” section, requested the logo be uploaded, and began a discussion suggesting the page be moved.

Ethically this is about all I think we should do. It’s up to you now. We’d love to see a well-written, immaculately cited Wikipedia article for this great thing we’re all involved in.