In this instructable we are going to build a 2 1/2 inch LED display with cheap 5 mm LED's.
Step 1: Materials and Tools
(8) 5MM LED's
1/4 Inch plywood
Electric are aluminum tape
Soldering iron and solder
Hot glue gun
Step 2: The Base
Cut a piece of plywood 3 inches by 1 1/2 inches.
Then drill 8 1/4 inches holes as in the photo above.
Step 3: Build the Mask Layer
Cut a piece of cardboard the same size as the base.
Next trace the holes in the base on to the cardboard.
Then draw lines from hole to hole as pictured above.
Now highlight as shown in picture 5.
Remove all highlighted areas (if you remove to much like i did it is OK we will fix that later).
Step 4: Putting It All Together
Glue the LED's in to the holes in the base.
Then glue the mask in place and fill the voids in the mask with glue as shown in picture one(to defuse the light).
Next place strips of aluminum or electrical tape on the base as pictured (this fixes any mistakes you made in the last step).
Now cut a piece of paper to fit over the mask and glue it in place.
Step 5: Finishing It Up
Bend the LED ground leads down in two "Xs" and solder.
Then solder a short piece of wire from "X" to "X".
Now solder a piece of wire to one of the "Xs" as ground.
Step 6: Using It!
You can connect a three volt battery's ground manually to the ground of the LED's and the positive to the positive of the LED's (each LED lights up a segment) or use an Arduino.
Just make sure that you have a 220 ohm resister connecting the Arduino and the LED's.