EL wire can’t take sharp bends without breaking. To create the
hard corners that discerning digit-users crave, run it out the back
through a hole, loop it around underneath, and bring it back up at
the different angle.
4d. Once the digits are affixed, rip away the paper underneath,
bit by bit.
4e. Trim any excess EL wire off the digits. If you’re using precut segments, move the end caps onto the
new ends; otherwise, cap the ends with a bit of heat-shrink.
4f. For the other, non-ground leads, twist them together into a single mass on each side of the ribbon
cable and solder them to the 2 pins that connect to the power supply.
5. CONFIGURE AND RUN THE SOFTWARE
5a. Download and run the Speed Vest software, speedo_ 4.pde, from makezine.com/19/speedvest as
in Steps 3c–3d. When the program starts, it cycles through each output pin in order, so you can identify
which pin feeds to which digit. At this point the numbers should light up in random order.
5b. Unplug the ProtoShield and use a multimeter to probe and map the connections between the
Arduino output pins and the digits. Then edit the array definitions for onesPins and tensPins at the top
of speedo_ 4.pde to reflect the associations. Edit and rerun the software as needed until the numbers
boot up in order.
5c. Test the system on the bench by holding the 2 halves of the wheel sensor and brushing the magnet
past the switch in a regular rhythm, to simulate the rotation of a wheel. At this point, we found it very
gratifying to see our work light up!
107 Make:
