Near-space Photo Update #1

The project is moving along.  I've ordered the balloons, and found a used Canon Powershot SD600 on Ebay.  The camera's gears are stripped, so the lens won't retract, but it apparently still takes photos and was $20.

Several people have expressed interest in helping, so there should be a pretty good bunch.  We're trying to decide where to launch from next.  It's tempting to try to drive somewhere that will allow a more likely landing zone within cell phone range, but I think we'll just launch from the Physics Building rooftop.  We'll have to watch the winds.  The picture below shows a launch from the Physics Building today at noon:

As you can see, today it would have followed 64 pretty closely.  This would be quite fortunate.

To maximize our chances of recovering the balloon, I'm considering making an antenna for the cell phone.  The antenna could hang down from the craft, and be tipped with a blinking LED for greater visibility.  This way, even if the craft ends up far from a cell phone tower, we'll have a better shot of at least some data reaching us as it falls.

We may also remove the battery pack from the camera and wire in our own.  I trust a set of lithium ion AAs more than a used NiCd rechargeable.

While a streamer seemed sufficient at first, I think a real parachute will be safer.  Now I've got to find or make one.  To minimize weight, I think we'll use a much smaller styrofoam body than the MIT students.

I just found a video that details how to make a directional cell phone antenna with coffee cans.  This might be something to consider.

Near-Space Photo Project

I loved model rocketry as a kid, and I always wanted one of those rockets with a camera.  This project looks to be much cooler.  Although the coolness factor of this project is reduced by the fervor surrounding the success of MIT students' near-space photos, this is still going to be lots of fun.

Essentially, I hope to take pictures with a camera attached to a weather balloon.  The students I linked above give nearly step by step instructions, so this should be obscenely easy.  All you need are a sounding balloon (already ordered, $30 for 2), a camera (Canon, to take advantage of the firmware needed to take pictures at a given time interval), a cell phone (to provide GPS tracking to locate the thing after it lands, $50), and a vehicle.  I think I'll just steal the styrofoam cooler idea for the vehicle, although I think I'll use a streamer instead of a parachute.  Then you need extra batteries for the cell phone (although maybe not), and some heat packs (also maybe not needed).

The camera firmware is CHDK, and the tracking will be done with InstaMapper.  I'll just buy the cell phone from Best Buy; a used camera will be the hard thing to find.

Cell phone coverage is a worry.  To get GPS data from the phone, it'll need reception.  The coverage map for boostmobile above will suggest launch location.


I'll use this Balloon Trajectory Forecast tool to try to figure where the thing will land.  Here's what the trajectory might have looked like today:

 

Here, the vehicle ended up almost 50 miles away, 30 miles northwest of Richmond, 10 miles from Kings Dominion.  This would be bad, as this is not quite in cell phone range, it seems.  Of course, this will change day-to-day.

More to come on preparations for launch!

Low Power Home Server Project

For too long I've left a computer running in my house to act as a little server, eating up electricity and heating up the living room. I general have used old machines that are useful for little else, but while these computers are essentially free, they use your standard 300 W power supply.

My goal in this project was to find a cheap server configuration that I wouldn't feel guilty about leaving on all the time. I went ahead and bought two 1 TB hard drives; these are cheap as free nowadays. But what to use for the mainframe?

I thought about the Eee Box, a lost cost, low power desktop. Running Linux, it would be as flexible as I could hope for, and I could plug in the TB drives with a USB enclosure, but the price, at $300, was a bit steep. I looked at all in one network storage solutions such as this one from Netgear, but the cost was still a bit more than I wanted, and the flexibility was essentially nil.

It was the Eee Box that reminded me of the Eee PC netbook I wasn't using. This Eee PC was an old Celeron 900MHz model, clocked down to 630MHz. I had always found it difficult to use; the screen is just a touch too small, the keyboard was painful, and it was just plain slow. But, as a server I wouldn't have to interact with locally, it became very attractive.

I found here that the Eee PC draws about 910mA when on but with the screen off. With a ~10V power adapter this means about 9W. Running a USB hard drive adds around 160mA when idle, or 500mA when busy and the heaviest CPU and SSD usage pulls another 250mA This means I would be pulling about 11W at idle, but only as much as 16.5W busy. That's like one of those compact fluorescent bulbs running all the time. Not too shabby.

I picked up a two drive USB enclosure from Newegg, so next I had to decide how to do backup. A TB is beyond my current needs, so mirroring the drives was my plan. But, should I set them up in RAID 1? This was the idea, but I decided this was a mistake. Faulty writes to a RAID 1 still result in data loss. The smart approach is to use one disk as the main data drive, and set the other up as a backup.

After I installed Ubuntu, I wrote a simple RSYNC script to do the backups for me, and added it to cron for thrice a week. Here's the script:

#!/bin/bash

rsync -avc --progress --log-file=/home/my_user_name/rsync_log/$(date +%Y%m%d)_rsync.log /media/data/ /media/backup/

Now, my data is backed up three times a week to the "backup" drive. I was worried about the speed of the Eee and the USB enclosure for serving movies, but I haven't seen any problem streaming movies to my set top box yet. There is no doubt that copying big files is slow, but it's managable.

I then set up LAMP for serving, UFW as a firewall (redundant, since my router is acting a firewall, too), and NX for remote access. After port forwarding on my cable modem and router, I can access this machine through ssh from anywhere. My next plans are to setup sharing with my XBox 360 and use a spiffy sharing tool like Tonido in case I start to hate Samba.

Overall, tons of fun, cheap and eco-friendly. How can you go wrong?

Why did I start a blog?

Why, indeed. I guess I wanted one place to put up thoughts and interesting stuff. Hence, this blog, or blarg as I will refer to it. Since the blogosphere is so played out by now, I don't think I'm in danger of looking trendy. Anyway, clever blog name? Check!

The real test: how long until I make a real, substantive post?

Meta-post complete.