3 ms·
> someone wants to run a rainbow pattern on an LED strip > I hope they don’t try to control a light strip with more than 83 LEDs on it! That would consume all t
by bombela 2y ago
> someone wants to run a rainbow pattern on an LED strip
> I hope they don’t try to control a light strip with more than 83 LEDs on it! That would consume all the RAM
Why do you need to store the pattern in RAM at all?
I would compute the next RGB and shift it out one LED at a time. Maybe you were thinking of using DMA for some async work?
- jonp888 2y agoThe way these things work(so far as I know) is that for the data to be passed along the chain the gap between transmissions can't be greater than 50 microseconds. Of course a skilled engineer could write a tight output loop that computes and outputs every value on the fly with a guarantee that the time budget won't be exceeded, but your average Arduino user probably doesn't have the knowledge to do this. So all the control libraries that I know allocate a memory buffer for the whole output stream and let the user update it whenever they want.
- TaylorAlexander 2y agoThat’s right. I’m really thinking of beginners, and as you say all the existing libraries I’m familiar with store the string state in RAM.
- TaylorAlexander 2y ago> Why do you need to store the pattern in RAM at all? That’s how the popular libraries do it. Not strictly necessary but the whole point of my warning was to make sure any beginners who saw this understood that this board has serious limitations compared to other options.
- bombela 2y agoThank you for the clarification.