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Ragnar Wasatch Back Light Vests

Posted by JEC on June 24th, 2013

We, along with local gym Rage Fitness were asked to sponsor a relay team for the 2013 Ragnar Wasatch Back relay race.  Teams of 12, 6 or 3(!) take between 17 and 48 hours to run almost 200 miles through Utah’s mountain ranges.

Since 1/3 of the race takes place at night, the team wanted an easy way to identify their support vehicles and team members.  They asked us to come up with a neat LED display of some sort.

For the two cars (both of which had roof racks) the choice was fairly easy.  We installed strings of RGB pixels around the roof perimeter.  They were controlled by portable playback boxes and sealed lead-acid batteries.  We’d designed this portable system several years ago for a theme park on the east coast.  As the playback boxes moved through the park, an on-board GPS system would trigger various patterns and colors, depending on where the system was currently located.  It gave the park entertainment group a way to match the moving lights with local decorations, which was pretty neat.

In this case, we had a pair of the playback boxes left over, and they were perfectly suited for the job.  The lights ran a ~15 minute loop of different looks, and the batteries easily powered the system through the night.

The runners all loved having such and easy-to-find landmark amidst a sea of other vehicles and people.  Over 250 teams participated, each with 2 vans and 6-12 people.  Makes for some crowded mountain roads and parking lots.

IMG_6450

 

For the runners themselves, we needed a different approach.  The result had to be durable, fairly lightweight, resistant to the elements and cleanly executed.  And, we had about 36 hours to complete them.

Last year, we designed the pixel-mapped jogging jacket.

It was awesome.  However, it was form-fitted to a single person, and that wouldn’t be convenient for an overnight team to share.  So we started differently for the team vests.  Race rules said that each night runner had to wear a yellow reflective safety vest, so we purchased a handful of them from Lowes.

IMG_6443

 A somewhat flexible grid of lights seemed like a good idea.  So I grabbed some bits and pieces from the local craft store.

Plastic Yarn Grid

Plastic Yarn Grid

 

Fake Leather & Sheer Synthetic Fabric

Fake Leather & Sheer Synthetic Fabric

Clear Vinyl, Heavy Gauge

Clear Vinyl, Heavy Gauge

A 7 x 7 grid of smart pixels was attached:

IMG_6440

DMX Playback Card

DMX Playback Card

The circuit board was left over from a different project.  It was designed to record incoming DMX, save it to an SD card, then drive 7 x RGB ‘dumb’ strips (ie, add +12v, then ground the red, green or blue lines to build different color mixes).  It was easy enough to rewrite the firmware and bypass the FET output stages in order to drive the smart pixels.  Plus, using old stock saves $300 in overnight PCB charges.

IMG_6444Add velcro, diffusing layers and sew the whole pouch to the stock jacket.

Test Pattern

Test Pattern

The vests worked wonderfully well.  Tons of compliments from other runners. There was no chance that our team’s runners would pass the support vans in the middle of the night unnoticed.

Running Vest at Night

Running Vest at Night

Night w/ flash

Night w/ flash

 

The lights were crazy bright, even though I’d compressed their maximum intensity to just 68% of normal.  The attached LiPo battery packs were easy to recharge and contained more than enough power to get through the night.  44 frames per second of DMX playback made the patterns and transitions silky-smooth.

All in all, a great success.  The runners vow to return next year for another round.

If there’s any interest, I’ll track down some video clips of the vests in action later this week.

-John

2 Responses to “Ragnar Wasatch Back Light Vests”

  1. Wolfgang Says:

    Of course there is interest in the video clips! Thanks for sharing. Awesome feat to accomplish all this in 36 hours, congratulations!!

  2. stephen provost Says:

    did you find the video clips?
    I see this project can be done any time of the year!
    stephen