Max screen size with Teensy 4.1?

I am using a Teensy 4.1 + SmartLED shield to drive multiple P5 64x32 panels. So far I have 12 panels chained giving a total screen of 192x128 px, working great! I would like to add more panels to make a bigger screen. How large could I go (in theory)? What are the main limiting factors and what can I do to mitigate them? I am not using any animation, my display is just showing text and rectangles. Thanks!

I have gotten that size to work but have not tried to go bigger. I suspect we will need to wait for a teensy 5 for such ambitions.

The limiting factor is mostly the amount of data that can be pushed out at 20MHz. When you add more pixels you need to lower the color depth and/or the refresh rate. To drive more pixels with high quality it’s better to drive chains in parallel which you can’t do with a single Teensy. You can do that with the hzeller library for Raspberry Pi.

Feel free to try out larger panel sizes without actually adding panels by setting the sketch up for more panels and see how it looks with the panels you have. If the settings look good with few panels, it most likely will when you add the additional panels.

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Would it be correct to say that 6x 64x64 (128x192) 1/32 panels with GIF decode or video stream via USB when using the latest Teensy 4.x board would give a reasonable refresh rate?

Not sure, but you can try it if you’re driving even just a single panel:

Feel free to try out larger panel sizes without actually adding panels by setting the sketch up for more panels and see how it looks with the panels you have. If the settings look good with few panels, it most likely will when you add the additional panels.

I’m not sure if the GIF decoder can keep up with that resolution, but again you can try it. It shouldn’t lower the refresh rate, just the GIF update rate

@davec @Matthew_P why not go to rPi? With my lib you can keep your arduino code and run it on Pi as if it were an arduino, and output on rgbpanels at resolutions of up to 384x320:

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@marcmerlin

This is great thank you! I already have the dragon board thing!

Hi Louis,
currently I want to try the large display using teensy 4.0 with P10 32x16 led panel.
is it possible to drive the panel 512x96 pixel with daisy chain 96 panels?

thanks
emhatek

No. Regardless of what you are using to drive it, you can’t really drive more than 30K pixels in a single chain, and even there it’s with more limited pixel depth.
To run 50K pixels, you either want multiple boards, or an rpi with 3 channels to spread the refresh load on 3 channels

Hi Marc,
Based on the parralel connector at rpi rgb is 3 hub connectors, how to drive the 32x16 panel modules with 512x96 pixel with aspect ratio 6 rows panels and 12 column panels? My opinion, i need 6 parralel hub connector.
Thanks for your great advise.

my apologies for the delay. You can connect the panels however they will fit as long as you get 3 rows, and then you can tell the library to rotate or mirror the display if needed.
For instance, I just built Marc's Blog: arduino - Putting some P5 64x32 Azerone Panels To Good Use, a Big 128x192 Matrix where the display is the wrong way around, but I tell the lib to rotate it 90 degrees and I get the framebuffer I wanted.