Cell reception

One of my biggest fears for this project is that the payload will come down safely with no damage to the cameras but have no cell service to send its GPS coordinates to Instamapper, leaving me absolutely no idea where it is.  Now I'll have a general idea using the balloon tracking predictors mentioned earlier, but if that's off by a mile or two, it will make searching for it very unpleasant (and finding it less likely).

LA County coverage map (boostmobile.com/coverage)

But after a quick check on the coverage map for the phone, it turns out I should be adequately covered at both the launch site in the desert and the general landing area in the IE.  There are a few splotches of "Fair" coverage which I will avoid if possible, but I'm pretty confident now that cell reception won't be a problem. Whew!

My second camera

Found another great deal on Craigslist- this Canon A480 10 megapixel camera for only $40!  It was in surprisingly good condition, with barely a single scratch on the entire thing.  Everything works great (and I have an extra 1Gb card now too).

Of course the first step once I got home was to install CDHK.

So to recap-

Get 2 cameras:      Check
Buy new SD cards: Check
Install CDHK:         Check

I now have all my electronics hardware! The final things to finish are picking the balloon, making the enclosure, and attaching/testing the parachute.

CHDK up and running

After a few false starts, I got the correct version of CHDK running on the SD400! 

Start-up splash screen

Script menu with Ultra Intervalometer running

Figured out how to load up the 'Ultra Intervalometer" script, and wanted to test it out.  What better way than to slap the camera on my windshield and drive on the freeway?  Yesterday on my drive into work I set up the camera to take a picture every 5 seconds.  Everything worked as expected and the suction mount stayed in place.  Combined all the photos into the video below (for the HD version check out vimeo)-

More Inspiration

In an unrelated search today on Arduino boards and GPS units (for another overly-ambitious project), I stumbled upon another California group doing high altitude balloon launches. The California Near Space Project.  They use HAM radios and APRS for tracking with various different setups.  I love how small their payloads are. Compact and efficient!

Their payload from the August 30, 2010 flight (CNSP)

They've already done 4 flights to date from the San Jose area, and actually have one scheduled for this Saturday (Feb 5, 2011)!  Check them out if you're into Ham radio.
[I used to be N3XUP, but that expired 5 years ago.  Somehow I still show up on this directory for Cogan Station, PA.  So does my Dad and a few of my friends.]

The winds, they are (always) a changin'

While I'm trusting my phone to tell me the final GPS coordinates of the payload, it's helpful to know the general area in which it will land.  Not only for reasons of finding it but also for planning.  If I launched the balloon from my condo, for example, it would end up way out in the Pacific past Catalina.  Not ideal.  Thankfully there are a few online trajectory predictors out there which can help with this.

The best one is CUSF Landing Predictor 2.0 provided by the University of Cambridge. The preset locations are all in England, but you can input any starting coordinates you want (as well as ascent and decent rates too).  Once the simulation is done, the flight path is overlaid onto Google Maps.  And if you want, the raw data can be exported as CSV or KML files.

Because the exact wind patterns are always changing, I won't really know my exact starting point until the day before the launch.  My target landing area is still Riverside/Moreno Valley.  Not many mountains or people to deal with, and I'd like to avoid LAX traffic for obvious reasons.  And there are plenty more chances of landing in a field were recovery is easiest. Since I'm really at the mercy of the winds, I very well might delay the launch until the winds are the way I like them.

Videos (not mine)

Found a great collection of videos today from similar balloon projects.  Gives you a good idea of what it should look like.  One of the videos is by a group in Livermore, CA made back in March 2010.  Pretty cool, but still haven't found an example from SoCal.

http://wn.com/High_altitude_balloon

"New" Camera (1 of 2)

On Sunday I picked up this Canon SD400 camera off Craigslist for a reasonable price of $37.  She's a little beat up, but works perfectly.  This one should do well as my horizontal camera.  Once my new SD cards come in later this week, I'll get to work loading CHDK and setting up the intervelometer.

 Still searching for the second camera (and contemplating on whether to add an IR one as well), though I may just go with a new Canon A490, which are relatively cheap, even new.

Parachute assembly

To my detriment at times, I usually follow two mantras- "if it's worth doing, it's worth OVER-doing" and "DIY". I realize I could have just purchased a parachute somewhere, but any idiot can order a parachute online.  It takes  a semi-skilled idiot to make their own parachute.  After finding a template for a hemispherical chute, I picked up the brightest orange rip-stop nylon I could find.

Not having access to a sewing machine and not wanting to sew the whole thing by hand, I found an inexpensive compromise...

What you're looking at is a $15 sewing "machine" I found at Target.  How well does it work?  Well, as good as you would expect from something of that price.  Actually, if you just use the wheel to advance the needle instead of the motor (which is way too fast to control) it works pretty nicely.  Expect some sore fingers.

 

Next up will be to attach the cords and test it out.  I'm still not set on using this one, but I'll wait to see how well it works.  I have a feeling it needs a much larger vent.