OpenSourcery

Now that the days are getting shorter, bike commuting demands some lights - and the brighter the better! To this end, I recently acquired a powerful LED flashlight that mounts on my handlebars. The light contains the impressive Seoul Semiconductor P7, with an advertised output of 900 lumens, but it comes at the cost of battery life. I wanted to find out precisely how long the battery would last, but I didn't feel like sitting around watching it. I also thought it would be cool to see how the intensity changes over time.

Lacking a lumen meter, or any other sophisticated test equipment, I came up with a plan: My aging Canon camera, ImageMagick, and a little Perl. The camera came with some remote capture software, so I configured it to take a photo every 30 seconds, while the light was aimed at a white wall. Note that it's important to manually set the camera's shutter and aperture so that you get a consistent exposure. I also locked the ISO speed, white balance, and focus - no auto-anything to interfere with my measurements. Finally, I set the resolution to the smallest available setting, to save processing time later.

The next morning, I had several hundred JPEG files on my desktop. A quick perl script, and I had a CSV file ready for plotting.

#!/usr/bin/perl -w
 
open MAGICK, "convert *JPG -colorspace gray -verbose info: |";
open STATS, ">stats.csv";
 
while (<MAGICK>) {
  if (/Mean:/) {
    @fields = split /[()]/;
    print STATS "$fields[1],";
  } elsif (/Exif:DateTime:/) {
    @fields = split " ";
    $fields[1] =~ s/:/-/g; # convert to ISO 8601
    print STATS "$fields[1] $fields[2]\n";
  }
}

OpenSourcery is proud to sponsor the Clean Technology Alliance's special Smart Grid technology event tonight. The event will be hosted by noted expert Jesse Berst of GlobalSmartEnergy, who will chronicle the rapid growth of Smart Grid technology, forecast what's next, and point out the profit opportunities for regional businesses.

The sponsorship is a perfect fit for companies - like OpenSourcery - that practice what they preach. We're proud of our connection to renewable fuel development, intelligent urban growth, bicycle commuting, green energy-powered offices, and the consistent use of earth-friendly materials for print (that is, when we print anything at all...).

Smart Grid brings together moderator Jesse Berst and a panel of experts to discuss the state of the industry and where to go from here. This is a must-attend event for energy professionals, tech executives, and business leaders interested in the opportunities that surround a newer, smarter electrical grid.

Please visit the SAO's website to learn more, get directions, and register. We look forward to seeing you there.