Introduction: Lego Compatible Name Display

About: Electronics company in Boulder, CO

This project uses any number of Lunchbox Electronics Matrix Kits that you want to chain together and create a display for your name. You'll need one kit per letter and you can use as many boxes as you want! This tutorial assumes you have uploaded a program to an Arduino board before and that you have simple soldering experience.

Step 1: The Matrix Kits

The first thing you’ll need to do is build each Matrix Kit. For this, you’ll need a soldering iron and a Lego brick. Instructions to build them are included with each kit, or you can watch our video. Make sure to solder wire to the data and power ports instead of the female headers so that the LEDs can poke through the wall of the box. I used different colors so it made it easy to remember which wire was attached to which pin.

With all the kits assembled, the next step is to make sure they all work before attaching them in the boxes. To hook them up to the Arduino, follow the instructions on the GitHub. I used a solderless breadboard, but you can also wrap wires together to make sure they’re connected just for this test. All the boards can be daisy chained together and run off of one Arduino.

To perform this test, we need to upload the code.

Step 2: The Code

The code can be found on the GitHub. Open the Arduino sketch and look near the top of the code for a section called “Edit Here”.

In this section, put in your own name or letters between the quotes. Also change the number after maxInUse to the number of matrix kits you are stringing together. Now that you have changed the information, plug in your Arduino, upload the code, and make sure your name appears on the Matrix Kits!

Step 3: The Boxes

To hold each LED matrix, I picked a small cardboard box that you can find at Michael’s. They come in lots of different colors so you can mix and match them to fit what you want.

To allow each box to house a Matrix Kit, a hole must be cut on one side of the bottom of the box. I removed the lid of the box, flipped the box upside down, and used one side to put the Matrix Kits so that all wires are hidden underneath the box. The orientation I used to measure for the Matrix Kit is with the chip side facing the open bottom of the unit. This allowed for the LED matrix to be centered and against the top edge of the face. To make the cut, first use a tape measure and a pencil to mark the center of the box.

Next, place the face of one Matrix Kit centered on the box and use a pencil to mark the outline of where the LED matrix will be poking out.

With the square marked, use an Xacto knife to cut out the side of the box. This can get difficult at times, so ensure that you always cut away from yourself! If you feel like your cuts aren’t perfectly straight, don’t worry, try to make them tend to the inside of the square. It will be much easier to cut off some extra cardboard than to try to secure the matrix in a hole that is too big.

With the hole cut, try to put the face of the LEDs into the hole. If the hole is too small, shave off the edges with the knife until you can fit the LED array snugly. If the hole is too big, use some tape to affix it to the inside of the box and hold it in place.

Now, repeat this process for all the Matrix Kits you wish to use. When you have finished, you can move on to the next step.

Step 4: Finishing Up

Now that all your LED boxes have been finished, it’s time to hook them up. Attach the Arduino to the inside of the first Matrix Kit in the name. This box will serve as the brains of the whole string.

Next, attach the wires from the first matrix to the Arduino within the box. Then, carefully solder each following Matrix Kit’s wires to the backside of the preceding kit’s circuit board, ensure that each kit is attached together following the hookup guide on the GitHub. When you are done, plug in the Arduino using either the USB plug or the DC jack and enjoy having your name in lights!