4C - Cut two slits vertically
where you made the surface holes
in the aluminum foil. Stick the legs
of the LEDs in these slits and wire
according to the diagram in Figure
5. Put the Darlington driver into a
general-purpose IC circuit board to
make it easier to solder to.
4D - The last electronic step is to
solder the RC battery pack
connector to the 9V regulated
power supply. The very last step is
to glue the foam core board and
the cardboard with the LEDs on it
together. The final product
assembly should look like Figure 3.
The scoreboard could be
mounted inside a wood frame to
give it more durability, but that’s
up to you.
■ FIGURE 5. This is the wiring diagram for one digit. You
need to repeat it for the other digit.
Step 4 - Electronics
Now you’re finished constructing the VEX scoreboard.
There are endless possibilities when it comes to
programming what you want to display. All you need to
do is use digital outputs to turn on and off each segment
to create different numbers. Besides using the scoreboard
to keep track of baskets or goals, you could also program
it to count down, so you can practice those last second
I programmed the VEX MCU using a simple C code
editor called EasyC which works with the VEX system.
When I press a joystick up, it adds one to a variable. Then,
using a look-up table it converts the variable to a decimal
number and uses it to display a digit.
For counting basketball shots, the system I’m going to
use consists of a few
different sensors. I plan to
put an ultrasonic sensor
below the net to keep track
of the number of made
shots. For missed shots, I’m
going to attach an
accelerometer to the back
of the basket to measure the
movement from the ball
hitting the backboard. Then,
using some simple math, the
scoreboard could display
some cool data such as
made shots, missed shots,
shooting percentage, and
much more. Use your
imagination to invent your
Have fun! NV
QTY DESCRIPTION PART NUMBER
56 Red LEDs
2 Darlington driver eight-channel
1 Dual general-purpose IC PCB
1 Wall adapter power supply 9 VDC 650 mA
1 RC 7.2V battery pack connector repair kit
Hot Glue Gun
Now that the basic frame of the scoreboard is
complete, it’s time to install the LEDs and wiring.
4A - Tape or glue a big piece of aluminum foil across
the first piece of cardboard that you cut out and using the
black cardboard piece as a template, trace all the
segments of the two digits onto the aluminum foil.
4B - In each one of the 14 segments, mark four evenly
spaced dots where the LEDs will go. To prevent the LEDs
from shorting out, cut and remove a small square of
aluminum foil behind each LED. Don't cut deep; just
scratch away the surface of the foil using an X-Acto knife.
Now you’re ready to install and wire all of the LEDs in
SparkFun.com part #COM-00528
SparkFun part #COM-00312
RadioShack model 276-159
SparkFun part #TOL-00298
Foam core board - You can get this at almost any drugstore or arts and crafts store.
Cardboard - Staples item #426426 (five pack). You probably will only need one or two of
these boxes or any other cardboard of similar quality can be used.
Black posterboard - Office Depot item #858430 (five pack). You only need one of the five.
Seven-segment display template - You can download this at www.nutsvolts.com.
Note - This article assumes that you
already have a VEX development kit. If
not, check out www.vexrobotics.com