How to control a LED matrix 8x224

Hello, everyone.
I would need help understanding which Arduino I should use for my thesis project.
For this project I will use 28 WS2812B 8x32 LED arrays that will be divided into 4 strips, so each strip will contain a total of 1792 LEDs. What these LEDs will have to do is just loop some “news” as if they were headlines and stock market data, obviously all coordinated.

Given these premises, which Arduino should I use?

I searched in the forum but I have not found an exact answer to my questions (given that I have never used Arduino and therefore I do not understand so much).

Thank you very much.

Are you intending to make a scrolling text display, or do you also need graphics? Also, how often are you intending to update the display? That large of a display will not be suitable for rapid animation.

Are these four strips by chance echoing the same information?

Thanks for your replies. Yes, I need to make a scrolling text and I need to use some special glyphs designed by myself. In theory, everything that it will be on the LED board will be preset, without any need for real update, but the text on the LED board will change approximately every two minutes. And not, three strips are going to show some number and stock exchange news, and the fourth strip is going to show the "breaking news". So can't I use Arduino for my project? Because I saw some very long LED boards project on internet done with Arduino Uno.

UNO is most certainly not possible, you might be able to use a Mega by reusing the same pixel buffer for each of the four strips, but that will take up 5376 bytes of the 8k of available dynamic memory. If you are intending to use wifi to obtain the data to display, there will probably not be sufficient memory. The Nano 33 IOT could probably work, or a multitude of other wifi capable boards.

divided into 4 strips, so each strip will contain a total of 1792 LEDs.

Each independent LED needs three bytes of SRAM memory. So for 4 times 1792 you need 21504 bytes. That is quite heavy for most Arduinos. The amount of storage memory limits the number of LEDs you can control.

Also the more LEDs you have the longer it takes to update them. As a rough guide each bit of memory takes 1.25uS to send, and as you have 8 bits in a byte, your 21504 bytes will have 172032 bits in it taking 0.21504 seconds to update.

So do you recommend to use another controller? Or another Arduino? Do you think it's possible to do what I want? And if I use a controller which has 32KB of SRAM, can I connect all my led stripes to one Arduino? Sorry, I'm new with these things, and I don't have so much time to understand how to realize my project.

And if I use a controller which has 32KB of SRAM, can I connect all my led stripes to one Arduino?

Yes

So do you recommend to use another controller?

I would look at the Teensy series of controllers.

And isn't Arduino Due, which has 32Kb SRAM, correct for my project?

Just be careful how you wire it, all the more advanced microcontrollers uses 3.3V, not 5V. Usually they have a 5V to 3.3V regulator on-board, but you may have to use a buffer for the signals and switches must not be wired to 5V or have pullup to 5V.

Can you give a better description of your overall project? You mentioned having the displays scrolling numbers, stock information, and breaking news, how are you going to be getting that information into the arduino? That can be done using the USB connection or a serial cable through a computer, but if you want to use bluetooth or want to pull the information directly off a website you might want a controller that has bluetooth/wifi built-in. How fast do you need the information to scroll across the display? Using a single board to control that many LEDs means you can only update the displays about 4 times per second, so about 8 seconds to scroll across the display if it is 32 pixels wide, moving 1 pixel per step. If that is too slow, you may need to use a separate controller for each display panel. You also have to consider the amount of time your code will spend obtaining the information for the displays - any time spent in that portion of the code will slow down the scroll rate.

david_2018: Can you give a better description of your overall project? You mentioned having the displays scrolling numbers, stock information, and breaking news, how are you going to be getting that information into the arduino? That can be done using the USB connection or a serial cable through a computer, but if you want to use bluetooth or want to pull the information directly off a website you might want a controller that has bluetooth/wifi built-in. How fast do you need the information to scroll across the display? Using a single board to control that many LEDs means you can only update the displays about 4 times per second, so about 8 seconds to scroll across the display if it is 32 pixels wide, moving 1 pixel per step. If that is too slow, you may need to use a separate controller for each display panel. You also have to consider the amount of time your code will spend obtaining the information for the displays - any time spent in that portion of the code will slow down the scroll rate.

Since for now I have only ordered the LEDs and have not yet been able to understand what kind of board to use I can not give much technical information. But I can say that: 1. The "news" will already be set up, they do not have to be taken in real time, but simply I have to think of long strips of text that continue to flow, slow enough to be read. 2. I was advised to program Arduino with the NeoPixel library.

Basically I have to understand which board to use to control these four strips in the most effective way possible and without having to deal with a very complex code.

Thank you.

Translated with www.DeepL.com/Translator

Have you considered how you are going to power the displays? An 8 x 32 panel has 256 pixels, at full brightness on white a single pixel will need around 60mA at 5 volts, which means a bit over 15 amps to light the entire panel. With scrolling text, the average current requirements will be a lot lower, but even at 5 amps per panel, with 28 panels you would need a 140 amp power supply.

david_2018: Have you considered how you are going to power the displays?

I bought a power 5V 40A 200W (for only one panel) because I need to display only to color (green and pink) so never white and never the maximum energy.

otta98: And isn't Arduino Due, which has 32Kb SRAM, correct for my project?

Yes. But you will need a level shift from the 3V3 system up to 5V. A level shifter designed for I2C will not be fast enough. I use a 74HCT14 to do the conversion.

However, a faster processor does not mean a faster update because the timing of the data to the LEDs is fixed.