Demonstration of scoreboard counting from 0-13:
Step 1: Materials
Foam core board- You can get this at almost any drugstore or arts and crafts store
• Cardboard- Staples item #426426 (5 pack) You probably will only need 1 or 2 of these boxes
• Black thin cardboard- Office Depot item # 858430 (5 pack) You only need one of the 5
• (56) red LEDs- Sparkfun part #: COM-00528
• (2) Darlington Driver 8 Channel- Sparkfun part #: COM-00312
• Dual General-Purpose IC PC Board- RadioShack model: 276-159
• Wall Adapter Power Supply 9VDC 650mA- Sparkfun part #: TOL-00298
• Seven Segment Display Template. Attached
• Wax paper
• Aluminum Foil
• RC 7.2v Battery Pack Connector Repair Kit- RadioShack #: 23-444
Total cost: around $110.00 depending on where you get your parts
• Soldering Iron
• X-Acto Knife
• Hot Glue Gun
Step 2: Construction of Front Surface
Cut out a rectangle 18.5” by 15.5” from the foam core board, cardboard, and thin black cardboard. Also, cut out the black segments from the template. Next tape the black cardboard on top of the foam core board lightly along the edges, this is only for temporarily. From the bottom of the foam core board measure 2.5 inches up. Draw a very light line running across the black cardboard 2.5 inches up. This will be your base line, lay your template on this line. Move it 2.5” from the left side. Now use the template as a stencil and draw the seven segments on the cardboard. Move the template 2” from the right and repeat the process.
Now that you have all your lines drawn on the cardboard it is time to cut. Using your X-Acto knife carefully cut through the black and foam cardboard. The slower you go, the better it will look when you are finished. It may help to use your ruler and line it up along the lines. Remember any vertical lines are slightly slanted, don’t cut perpendicular to the top or bottom of the poster board. Once you are done cutting, undo the tape that held the black and foam core boards together, but do this carefully or you might tear the black cardboard. We did this so you only had to cut once, and things would be lined up perfectly.
Step 3: Construction of Back Panels
This is the most time consuming step. What we are trying to do is create small compartments to hold the LEDs. This step is what gives the scoreboard its depth. You need to cut out the following pieces from the cardboard; all of them are 1” wide:
Size A: 3” –Need 10 pieces
Size B: 2.5”-Need 8 pieces
Size C: 2.0” Need 2 pieces
Size D: 1”- Need 8 pieces
Once you have all of the pieces cut out, then you need to tape aluminum foil onto one side. (Double sided tape works great.) This is going to give each segment a very full look, by reflecting the light from the LEDs. Don’t forget that some of the little pieces have to have both sides covered in aluminum foil since they serve as a wall for more than one segment. Once this is done it is time to glue. Make sure that the digits are slanted to the left. Glue the walls onto the foam core board at the thinnest part of the wall. See figure 2. Now repeat this process for the second digit. Once this is done tape 3 pieces of wax paper across the top of the digits of the foam core board, this will disperse the individual LEDs and create more of a full look. Then glue the black cardboard onto of the wax paper. Now on to the electronics…
Step 4: Electronics
Now that the basic frame of the scoreboard is complete it is time for the electronics. Tape a big piece of aluminum foil across the first piece of cardboard that you cut out. Now using the black cardboard piece as a template, trace the two digits onto the aluminum foil. Now it is time to put the LEDs in place. In each one of the 14 segments draw out 4 dots of where the LEDs should go, evenly spacing them out. To prevent the LEDs from shortening out, cut a little square out of the aluminum foil behind where the LED will go. Don’t cut deep; just scratch away the surface of the aluminum foil. It is easy to do this by using an X-Acto knife. Now you are ready to wire all of the LEDs in each segment. Cut two slits vertically where you made the surface hole in the aluminum foil. Stick the legs of the LED in these slits. Follow figure 5 for the wiring. Stick the Darlington Driver into the general purpose IC PC board to make it easier to solder to. 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 should look something like figure 3.
Step 5: Conclusion
Now the Vex Scoreboard is finished. 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 this to keep track of made baskets, you could also program it to count down, so you can practice those last second buzzer beaters!
A picture of the code I used is attached. I programmed the VEX microcontroller in EasyC V2.