Hey, I wanted to pick up the question that has been stated a couple

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1

Hey,
I wanted to pick up the question that has been stated a couple of times previously. Is there meanwhile a possibility to run multiple matrices/stripes of APA102 LEDs in parallel with FastLED? I am currently using an arduino DUE.

Best

2

You can use multiple outputs but there is no parallel output support yet for SPI based chipsets in FastLED. (So basically it will write one strip then the next, etc…)

3

In this case the writing time will for all the matrices will add up?

4

Yes - and generally hardware spi is fast enough that it will out perform parallel bit-banged spi output, which is why I haven’t put a whole lot of effort into it yet. (On something like the due parallel bit banged output will get to something like 8-10mbps aggregate data rate which is still below the 12-24Mbps you can get with hardware spi)

5

Parallel output is a thing that works well for ws2812 style LEDs because it’s base data rate is so abysmally low - 800kbps - so even if you do 16 way parallel output, that’s still less than 13mbps data rate in total - which is still lower than I generally run apa102s at.

6

Thanks a lot. Would it in this case make any difference if I chain them in line or give each matrix an own data line?

7

If you chain them in a line you can use the due’s hardware spi output - otherwise you’re bit banging which tops out somewhere between 3-5mbps. (There is a hack on the teensy 3.x where you can get four hardware spi outputs - but nothing like that for the due at the moment)