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MAKE@SXSW 2013So far the coolest thing I’ve seen at SXSW has been this clever early-stage prototype from our own Matt Richardson. It’s a “dynamic bike headlight” that projects your speed (and potentially other useful information) onto the road in front of you as you ride.

The prototype has a Raspberry Pi for a brain, which is connected through its onboard HDMI port to an LED pico projector mounted between the handlebars. A Hall effect sensor, connected to the Pi’s GPIO pins via an adafruit Pi T-Cobbler breakout kit, detects revolutions of the front wheel. The software counts these, converts their rate into a speed in MPH, and sends the numbers to the projector for display on the road surface.

Matt showed off the proof-of-concept build this morning at Bike Hugger’s Built: Make & Tell event.

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Right now, the setup is battery-powered, and is limited to one hour’s use. Matt’s already making plans for dynamo power in a later build. Check Matt’s Flickr set, linked below, for more pics of the system in action.

Dynamic Bike Headlight

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Sean Michael Ragan

I am descended from 5,000 generations of tool-using primates. Also, I went to college and stuff. I write for MAKE, serve as Technical Editor for MAKE magazine, and develop original DIY content for Make: Projects.



  1. miroslava von schlockbaum says:

    if i had that thing, i’d run into a stopped car in front of me while looking down messing about with it. but then, i’m a klutz (with a nice broken clavicle to prove it)

  2. Is that velcro or zip ties holding it all together?

    1. Matt Richardson says:

      It’s all velcro. I wanted to be able to detach and reattach the development version without wasting materials.

  3. That is just brilliant. I love it!

  4. Malphas says:

    Looks nice only sad thing is, i see the light on the street but not the light that is comming from the bike.

    1. Malphas says:

      Dont know if i drive my car if i’m going to see the light on the street. I’m positionned higher and i like to see light on the bike so i could see the bike’s distance in my rearview mirrors make’ it easyer.

  5. robk says:

    there is one big problem with this;
    how do you see your speed during the day?

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