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Adam Davis
Works at Micro Basics
Attended University of Michigan
Lives in Ann Arbor, MI
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Signal processing software designed for amateur radio is being used to detect pings from the black box of the missing airline flight.

Go ham radio!
 
Looks like HAM radio software SpecLab created by Wolf DL4YHF, is being used to help find the black box recorder for the missing flight MH370;
  https://www.dropbox.com/s/qo57o3f1oyoful4/Screenshot%202014-04-07%2012.47.30.png

From the RSGB LF mail list;
"I have been amazed at the low tech methods apparently being used in the hunt for the 'pings' from the black box of the missing Malaysian plane. But today the BBC lunchtime news showed the Ocean Shield search ship using DL4YHF's Spectrum Laboratory, presumably with a 96kHz soundcard as its input - exactly the kit used for the recent amateur radio transatlantic tests on 29kHz. Well done, Wolf. Your excellent software may help solve this mystery. de Mike, G3XDV"

#hamr #SpecLab #MH370  
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Played with Sprint today, then took a look at the source code running Sprint on the website.  Here are a few observations.
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FOR SCIENCE!
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There is no flaw with the reasoning here.
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This is the CL package for the 128x1 pixel line imaging array TSL1401. I have the smaller CSP package I might take pictures of later, but here's this for those who enjoy looking at small things. The wire is 30awg wire wrap wire, and the capacitor is the recommended 0.1uF that is supposed to be placed as close to the imager as possible. Note in the close up that the end pixels are thinner and longer. They have the same surface area so they return the same exposure as the inner pixels, but they are thinner and closer so they can make longer pixel arrays by butting the dies up against each other with the same effective pixel density, while allowing for die cutting error. In most applications this won't matter, but sometimes it does, and it pays to read the data sheet carefully.

Three pictures taken at 10x, one at 40x. Ruler has 0.5mm marks.
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Digital theremin V2
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It's a lot of work for just a few cups of maple syrup, but it's fun and the kids are excited.
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The ending reminds my of my kids fighting in the backseat after I've told them to be quiet...
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Here's the next milestone of my filament profiler. I haven't done the full code yet, but it's reading both axis just fine. The geometry should provide 0.05mm measurement accuracy without subpixel interpolation for objects between 0.5mm and 4.5mm in diameter. Interpolation should more than double the resolution.

Next step is to add code to locate the filament exactly within the hole, then use a little trigonometry to get the diameter, knowing its location within the two cones of light.

If it's not obvious, I'm not using any optical lenses. This is projecting light onto the sensor, and the filament blocks the light, leaving a shadow.

One sensor isn't enough, though, since the shadow grows the closer the filament is to the light source. Mechanical means could hold the filament in place, but filament is stiff, and it would add significant drag.

With two sensors you can find out where the filament is exactly, then correct for the placement of the filament inside the cone of light.

Further by measuring along two axis you gain a little more information about the filament profile, such as roundness. This isn't perfect, but it's better than a single measurement.

I also did some speed measurements and the digital writes and analog reads are consuming way too much time, allowing only 8 measurements per second. I expected it to be slow, but not this bad. I'll work on the math first, though, and leave the speed issue for another day.


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We were just talking about the need for something like this at the last SD Robotics club meetup last week.
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Filament profile sensor, milestone one finished. Still a ways to go before having something useful, but the initial testing went as expected. 
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Interesting to see this development going :)
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I know stackoverflow isn't everyone's cup of tea, but for those that find the stack exchange way of concentrating expert information into one site useful, please visit and consider committing to the beta of the Fabrication and Manufacturing site. 3D printing is an obvious fit, but we hope to see questions and answers that discuss everything and anything that could be made in a makerspace. 
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Engineer, Software, Hardware
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  • Micro Basics
    Software and hardware design and engineering, 2004 - present
  • Lear Corporation
    Software Engineer, 2007 - 2010
  • Digi International
    Hardware Engineer, 2005 - 2007
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Make ideas fly!
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Embedded engineer - both hardware and software engineering.  Father of 5 boys.  Enjoys cycling (placed 1st in my category, 4th overall in a 24 hour ultramarathon race).

Learning iPhone/iPod software and hardware development (Made for Ipod program)
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  • University of Michigan
    Computer Engineering, 2005
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