The LED Matrix Backpack

I commute roughly 10 miles round-trip through Los Angeles each day for work. This is awesome (fun! exercise! no traffic!) and terrible (cars! nobody watches where they’re going! my body is made of soft meats and cars are made of terrible metal! oh god cars!). With the short winter days upon us, all of my evening rides are through the darkness… and I really don’t feel all that safe out there.

I have front and back bike lights, but they just don’t cut it. When I pass other bikers, I’m always startled to realize how small their bike lights look from a distance, and how long it takes me to notice them.

So, I grabbed an LED matrix I soldered together a while back from when AdaFruit first came out with (what was then the alpha version of) their NeoMatrix library, soldered it to an Arduino Pro Mini, uploaded the code, and sewed it all to my backpack.
The song in the background is Robert DeLong’s remix of Cigarette Barbies’ The Beauty Myth, if you’re curious
I think it came out pretty nice! It’s painfully bright in person, and the LEDs aren’t even turned all the way up. (The text scrolling across it just says “*****”. It was really tempting to write “Hey! Don’t hit me!” or “CAUTION” or something, but I really don’t want to needlessly distract any drivers that are that close to my back.)

Here’s what it looks like in the light:

For future projects, I have my eyes on the Night Bike 2.0, and the Spoke POV.


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