The Balloon Launch Project

Balloon project payload housing and spare GPS parts

Balloon project payload housing and spare GPS parts

I’m forming a group to work on a balloon-launch project. With a tentative launch date of June 2013, we plan to launch a weather balloon-powered payload to the mid-stratosphere, take measurements, and recover it.

The first question I always get is “Why”, and I invariably look up, seeking the depths of the sky for an answer. George Mallory, one of the first hikers to climb Mount Everest, was once asked why he felt compelled to climb the world’s highest peak. His famous answer was “Because it’s there”. Those that have ever felt the call of the explorer know how irresistible that is. I’ve come to love hearing people tell me “Well, people have done that before.” True, but *we* have not. Not yet, but we will.

We will not be the first to get to this altitude, nor will we be the last, but it isn’t a trivial task. For the trouble we’re going through to try to achieve our goals, we’re serious about doing some science while we’re there. Up there, we’ll be outside of typical FAA flight zones – this airspace is usually reserved for military use. We know its cold, we know the air is thin, but we also know it’s beautiful up there – a silent and rareified place where, in the words of Felix Baumgartner, you feel as if “you’re on top of the world.” We will collect temperature measurements, pressure measurements, and, of course, take some pictures. We will have the rare opportunity to change our perspective on the world for a little while, and maybe even make some ‘firsts’ while we do it.

In the end we’ve got so much going for us: a legacy of flights to build and improve upon, a hackerspace full of know-how and ingenuity, and the patience to know that we may fail here and there, but what we learn will get us to our goal with that much more experience.

We’re always excited to hear from people who are inspired by this project and we welcome anyone who wants to join the group, learn how to move the project forward, and contribute to the team effort.

Flowers made of light

When Karen (yes, that Karen) decided to host a DIY birthday party, and said that she wanted people to make flowers, my mind went blank. Mario brought casting resin to make plastic flowers, Roger brought color-changing LEDs that got used in a bunch of things. I saw flowers made of yarn, flowers made of vinyl, flowers made of piano keys, flowers made of filter media, flowers made of sheetmetal, flowers made of mylar, and of course, flowers made of Red Bull cans. Still having no ideas, I decided to ignore the party for a bit, and started salvaging some motors from a soon-to-be-recycled CDROM drive.

Then something clicked: At Tuesday’s electronics meetup, we used signal generators and oscilloscopes to display Lissajous curves. With a laser and some mirrors and some motors, I could make Rose curves! Those are flowers, right? Flowers made of light!

The only small mirror available was still much too large, so it got cracked into a bunch of sharp but useful little pieces. With some hot glue, some solder, and a quick trip to the bin of lasers, I had a rudimentary optical path. Joe helped set up a quick-and-dirty pot-and-FET motor speed control (inspired by reading an article about PC PSU testing a few days ago), and with a few more minutes’ work, the whole thing was stuffed into a project box and shooting flowers onto everything within reach, including Karen. Happy Birthday!


(Caution: Laser light emitted from this aperture. Warning: Whirling bits of broken glass within this aperture. Danger: Flowerguns are addictive.) 

Reset-on-LAN: An ethernet-aware remote reboot device from junkbox parts.

Testing the concept.

What do you get when you mix an old 10/100 NIC, a handful of components, and a home server that goes off into the weeds once in a while?  A network-connected reset button, and the ability to recover from the majority of mishaps!  The concept is simple:  Use a standalone NIC’s Wake-on-LAN capability to poke a different signal, specifically, the PC’s reset line.  Best yet, the whole thing costs less than $3, and goes together in under an hour. Not too shabby, when you consider that comparable network-aware remote-reboot devices go for about $200!

The important realization behind the project is that a WoL-capable NIC can run standalone, given nothing but power. It seems so obvious in retrospect! This same concept could be easily used to drive an SSR for true cold-boot capability, interface with a UPS for output-disable, or other functions.

(UPDATE: There’s prior art! Their version is called “whack-on-lan” and uses a NIC without the retriggering problem, so their circuit is much simpler.)

Lots and lots of detail after the break…

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Rule of Acquisition #141: Only Fools Pay Retail.

At the Hamvention fleamarket, Dustin got an amazing price on a Handheld Products 3800r barcode scanner, probably because the cable wasn’t included. The connector on the bottom of the scanner is a nonstandard 10p10c (aka RJ50), so most folks wouldn’t just be able to make one, but buying a $57 cable for a $1 scanner seemed silly. Further frustrating the situation is that Handheld (acquired by Honeywell) is pretty tight-lipped about certain info. The pinout for the RS232 cable (p/n 42206300) was easy enough to find, but the innards of the USB cable (p/n 42206161 or 42206203) proved elusive.


Luckily for Dustin’s iTrackMine habit, i3’s electronics lab had a set of 10p10c crimpers and a box of connectors (and a resourceful mentor geek), waiting to solve just such a problem. After building a little 10p10c breakout cable and a USB breakout cable, some breadboard jumper wires made it relatively straightforward to investigate every permutation until the device enumerated. (Note that ‘straightforward’ does not equate to ‘quick’.)

For the purpose of saving some hapless future scanner technician some time, the pinout is as follows:

USB pin number function color 10p10c pin number
1 +5 (Vcc) Red 7
2 D- White 10
3 D+ Green 2
4 Gnd Black 4

Two construction tips:

First, it’s difficult to position the wires in a modular connector if you’re not using every position. Stuffing the unused ones with little stubs of wire made it easy to guide the relevant wires into position.

Second, modular connectors can be reinforced by flooding the back with hot-melt glue. (This works very well on cat-5 patch cords.) Since this build used a flexible, thin USB cable in a giant 10p10c connector, the glue is the only reason it didn’t fall right out.