GLOW, SPEED RACER
With less than 12 hours
remaining before our
deadline, we began
work on our floor
display. We made a
mannequin to wear the
Speed Vest by casting Brady, using Mark
Jenkins’ packing tape
( tapesculpture.org). Add one bicycle and one bicycle
work-stand, and we were ready to wow the public.
It’s hard to know just how car drivers feel about the
Speed Vest, but so far nobody bicycling while wearing it has been honked at or run over. Meanwhile,
we’re now working on SpeedVest II, with four major
areas of improvement:
» Wirelessness If the rider forgets he’s plugged
into the bicycle when he dismounts, the electronics get yanked. In practice, this happens almost
every time, and we’ve had to resolder the connectors three times already. SpeedVest II will use
Zigbee wireless modules to transmit speed data
from the wheel to the Arduino.
Photography by Mykle Hansen
» Size In bicycle equipment, lightness is everything.
The Arduino USB board is handy, but contains
a lot of parts we don’t use. With a custom PCB
design, we can get the whole system much
smaller and lighter.
» Power The Arduino is powered by a 9V battery,
but the EL wire inverter has its own AA battery
and a separate power switch. The batteries run
out at different times, and turning the unit on and
off is a two-step process. Our improved single-board design will integrate the inverter, driven from
the same power source as the rest of the board.
» Speed range Bicycles are fast, and getting faster!
Our vest displays speeds up to 69mph, but the
current bicycle land speed record is 81mph. (And
that’s not even close to the drafting speed record
of 152mph, set by a bicyclist chasing a specially
designed car that pushed away the forward wind
resistance.) So we’re redesigning our numeric
display to show all speeds from 1 to 99 miles per
hour. We hope that will suffice for normal use.
We handily accomplished
our first mission: winning
The Hub’s Bike Gadget
Then we set about
testing the Speed Vest
in real traffic. We’ve had great success with it, and
the feedback from everyone who’s seen it has been
wonderful. Many people want their own.
Also, simulating a wheel with your hands, and
seeing how fast you can make the speed display go,
has become a strangely compelling party game.
Download all project code, schematic diagrams,
and templates at makezine.com/19/speedvest.
Keep up with the Speed Vest project