Light Vision (Raspberry Pi LED Matrix)

The Rough Plan:

A matrix display with a  Raspberry Pi that we can control over Wi-Fi with our own C# program.

Accurate execution:

First Versions:

The big problem with this project was that we had completely  miscalculated how to do the implementation with the lighting in the  beginning. We thought it would be good if we took individual LED strips  and then connect them to a large display. The idea is okay, but we have  planned the space very small, so I have tried several weeks to place the  LEDs to the millimeter. The cables were pretty thick and always broke  of the soldering pat. After a desperate weekend where almost all LED  strips broke, I decided to use PCBs and after one day everything works.

The Program:

We have developed a program based on C# and  using Visual Studio to control the matrix display. Before we even  started programming, we thought about a short list of requirements for  the program, which must be definitely fulfilled. There was then also an  extension list, if we still have time.

Requirements:

• Connect to server on RaspPi
• Converting input in the fields to LED control
• Create own pixel art - images and animations
• Display messages or text
• Add
• Control the program on RaspPi (set time, delay between tiles etc.)
• Predefined tiles

Add-ons for later

• more tiles e.g. stonks, weather or time
• Embedding of animations and images from the Internet community
• add GIFs/PNG/JPEG

Functions that the user has at the end go through page by page.

1. The  first image shows the default editor. Here you can click on each pixel  and give it a color, use the filler tool, erase, click on a color on the  screen and then transfer it to the selected color box, change the name  of the image and the display time of the image, insert a PNG/JPEG, which  will be scaled down. You can also select existing images and then edit  them.
2. The Animator is an advanced version of the Editor. Here  you have the same drawing functions as in the editor, but you can draw  your own animations. When you create an animation, you select the length  of the animation, and it is shown by the green dots at the top.  Additionally, you can insert GIFs which will be converted without  drawing. A special feature is that you do not have to draw frame by  frame, but can also adjust the display duration of the individual  images.
3. The template page shows the prefabricated special  fields, which we could finish at the end. First, the display of the time  with the clock and the value of the GameStop stock.
4. The  dashboard then shows all the straight active images and animations. The  animations are all animated as well, so you can tell the difference. By  dragging and dropping, you can move the tiles and change the display  order. With a double click on a tile, you get to the respective editor  for animations or images.
5. In the settings, you can then change  the color of the program and switch off that the tiles in the dashboard  are animated, because this has caused a slight confusion for some  people.

Connection:

After each save of the user, the Program sends  all the data that the Program has stored locally to the root server.  The images are stored in the form of bitmaps, i.e. an array of pixels with color values. Saving is made easier by the fact that we only store  images and animations consist of images, and then these are simply  reassembled as an animation when they are sent back. Every 15 minutes,  the Raspberry Pi asks the server for data. And then gets all the data  transferred.

What you need:

• Raspbery Pi
• thick Cables
• Power Supply
• 3D Printer
• Power cable with switch
• Some M3 nuts
• cooling Fans
• 3* LED Panel
• The program
• A root Server where you let the Server run. you can use a Raspberry Pi. We rented a server at Hetzner

3D print:

I would recommend to print most of the components in black. I had  printed the front panel in white myself, but this caused massive  ghosting, with the LEDs illuminating the adjacent chamber of the other  LEDs. To fix this problem, I printed the front panel with a color change, where only the first layer is printed in white and the rest in  black. The other components should print without problems with support. I  would also recommend Cura for this, as their support is better than  PrusaSlicer. You only need every part once.

Soldering:

Now that you have printed all the parts, take the front plate and place  the 3 PCBs on it. Next, take a strip of tape to securely connect the  PCBs as you solder them. Now take the backplate(Puscher) with the large  openings and screw the front panel and the pusher together. Be careful  not to move the boards between the pusher and the front panel while screwing them together. Now all you have to do is solder the PCBs so  that each pin is connected to the other pin so that the LEDs are all  connected to each other as if in a long row.

Connection to the Raspberry:

• Now you can take the lid and screw the  Raspberry Pi to it. I would recommend using the Raspberry Pi heat sink.  Don't be confused by the different backplates. The first one is only the  V1.
• You now need a 2 pin header to connect Ground and Din to the  Raspberry Pi. You also only have to connect one end of the boards to the  Raspberry Pi. Not only that, but you can connect the fans to the 5V  pins in red and the GND pins in black.
• Furthermore, you should  also glue two small fans, as the back of the LED boards can heat up very  strongly. It even got so hot that the plastic deformed.
• You can get the code for the Raspberry Pi on my GitHub page.

Power:

For the power, we use a power supply, because  the LEDs consume more energy than the Raspberry Pi can provide. In  addition, care should be taken with thin cables. If thin cables are used, you should take extra care that they do not burn through. A good  test is if you try it briefly with the cable, but have your hand on the  power switch to turn it off in case the cables are getting hot. We used  two cables to be on the safe side, because in the first test I created a  little glowing cable, which melted the isolation in one second.

But if you have never worked with high voltage, you should rather do so with someone who is familiar with something like this!!!

Srewing the Backplate:

Now you only have to screw the lid, you should be careful not to tighten the screws too much.

Conclusion:

                        I really liked the project and had a lot of  fun developing and building it. I put a lot of time into the development  and also had some misprints, as you can see in the last picture on the high stack of prints. I would rather recommend everyone if you do such a  project to develop it yourself, because you also learn so much more  than if you follow a guide or maybe someone is motivated to take my  project and revise it. There are even minor issues like overheating,  which we solved through the fans, but it would be more elegant to get it  running without active cooling. I really liked this project. I hope you  enjoyed this Instractable and have fun to build it. Let me know in the  comments what you think or if you have any questions? Thank you for  reading.

If you like to, check out my other designs too!