How many LEDS can teensy4.1 Drive ?

dallen

New member
Hi,

i am currently costing out how much to build a 600x300 matrix using 10mm pitch hub75 panels so question, how many leds can the teensy4.1 drive ?

I have 2 full screen applications NB a slide show pausing every 7 seconds and the second application is full motion video at around 25 to 30 FPS
Any advice greatly appreciated
 
I’m not sure if this will work. But with flexio + pll + dma i run 4096 leds & 178 fps. This uses 3 pins, 1 for data to external 32bit shifter. You can output to more than one bit, so you can try to output 8 bits. There are 3 flexio, but only 1 and 2 can use dma. So that maybe thats 16 bits parallel output. This will combine to 512 channels. So 400000 might be possible at 30 fps....
 
For HUB75 panels, the clock speed limits you to about 10-20k pixels in one daisy chain, unless you make some serious compromises. You could use a low color depth perhaps (3bit color instead of 24bit). Refresh rates below about 200 Hz don't work well because they flicker noticeably. The panel refresh rate is independent of the actual FPS of the video content, so it doesn't matter if you're displaying a slide show.

Since 600x300 is 180k pixels, you would need at least 9 parallel chains of panels (driven by separate controllers) for a display this size... I believe there is a RPi shield that can drive 3 chains, but Teensy 4.1 is only capable of driving 1 chain through the SmartLED shield.
 
Are you streaming the images/video frames over USB? If so you could use multiple Teensys in parallel to get the resolution you need if it’s not possible to do it all with just one
 
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