LED-11. Make a very big size 384 X 512 RGB Matrix #6(final)

 Finally, it is the day to install the 384X512 size LED signage in the cafe. Up to now, assembly, development, and testing were carried out in my office. Finished installing and testing Node-RED for minor bug fixes and electronic parts management. And to install the cafe, I disassembled the electronic parts again and took it to the cafe. Here we will install it again after reassembly.

reassembly

All 24 LED panels, aluminum profiles, Hub75 cables and wires were removed and reassembled in the cafe.

<Rear view of reassembled LED signage>

After reassembly, a simple test was conducted. Confirmed that it works without problems. The next thing to do is to fix the sign structure to the window.

<Test screen after reassembly>

The black line on the screen is invisible to the human eye.

<LED signage installation>

Four arms were connected to the LED frame and fixed to the aluminum window frame.

And after playing the LED content, I checked it outside the building.

<LED signage in action>

The 384X512 resolution of the LED signboard is quite high. Thanks to the implementation of high resolution, we were able to confirm a fairly clear picture quality.

Wrapping up

 After many trials and tribulations, a 384X512 LED sign was successfully installed in the cafe.

brief history

• In the process of making a frame to fix several LED panels, we experienced many trials and errors. The biggest cause of trial and error was the attempt to fix the LED panel using magnets. In the end, I gave up using magnets and drilled a hole in the center of the 20X20 size aluminum profile to change the method to fix the LED panel and make a sturdy frame.
• A single Raspberry Pi cannot make a 384X512 LED signboard. Therefore, in order to implement a distributed display using multiple Raspberry Pis, I used a method of transmitting video content to several Raspberry Pis in charge of LED play through the network.The LED image transmission method using the network was explained in "LED - 7. Distrbuted display system for very large RGB LED matrices".
• The player controls a total of 6 128x64 size LED panels. The performance of the player implemented in Python was not as good as I thought, so I made a new one using C++. When using Python, the performance was about 15 FPS, but the program redeveloped in C++ performed better than 100 FPS. If this level of performance was sufficient, it could be used.
• The LED panel uses an average of 11.7W/pannel and a maximum of 35W/pannel. Therefore, if 24 panels are used, an average of 280.8W(56.2A) and a maximum of 840W(168A) are required. Initially, three SMPSs capable of supplying a total of 805W of power were prepared. It was expected that this level of power supply would be sufficient. But a problem arose. There was a lot of noise on the LED screen. After searching for the cause, I found that the power supply of the Raspberry Pi was not stable. When the power consumption momentarily increases in the LED signboard, the voltage supplied to the Raspberry Pi using the same power rail momentarily drops below 5V. After much deliberation, I decided to use another SMPS exclusively for Raspberry Pi. This ensures that the power of the Pi is also stable, and that more power can be supplied to the LEDs. It is recommended to separate the power of the Raspberry Pi from the LED power and prepare an SMPS that can supply sufficient power.
• To reduce electrical noise, a tape with an electromagnetic wave shielding function was used around the part where the Raspberry Pi and near the terminal block.

 In this project, an indoor LED panel was used. Products for indoor use are relatively dark in brightness compared to those for outdoor use. Therefore, there is a disadvantage of not being able to see clearly in a bright day. If you want to use it in a bright place, please use an outdoor LED panel.

Because this project adopts a distributed processing structure using a network, it is easy to make an LED signboard with a size larger than 384X512. I hope you will try a bigger size LED signboard.

Now in My Cafe (Bluebird Soufflé) you will be greeted by a delicious soufflé pancake advertisement.