3

As the title suggest, what limits the number of "pixels" I can control in an individually addressable LED strip such as SK6812. Most controllers on the market I see are only up to 2048 pixels.

If I were to make my own controller I can simply circumvent this by assigning another signal pin to the next line and just time it in code. Is it the driving capability of the digital pin ? I thought each pixel in the LED strip will act as a repeater after it recieves its color. I can also just use a MOSFET to increase the current capability of the data pin if that's the problem.

So why do they stop at 2048?

JRE
  • 71,321
  • 10
  • 107
  • 188
DrakeJest
  • 887
  • 11
  • 39
  • 3
    If you look at the protocol, there is no limit, but the data rate is 800KHz (sic). Each LED takes 24 bits of data so you can address about 33333 LEDs per second. If you want about 30 updates per second per LED, you can have about 1000 LEDs. – user253751 Nov 24 '20 at 18:13
  • @user253751 ahhhh so it all boils down to how many updates per second you want. So theoretically if i have 5000 leds i will be able to update 6 times a second ? – DrakeJest Nov 24 '20 at 18:16
  • Yes, approximately. Also there's no way to count the LEDs. So the controller just has to send out a certain number of 24-bit colours and hope you have less LEDs than that. – user253751 Nov 24 '20 at 18:27
  • The number of addressable LED-Strips depends on the capability and IO count of your controller. If you are using an FPGA you can adress a lot of LED strips in parallel. – Dennis Ernst Nov 24 '20 at 18:42
  • It’s also worth considering the delay added by each pixel as it buffers the input signal and sends it to the output. It will be tiny, but 5000 * tiny may still be perceptible. Running strips in parallel (with multiple data lines) is a great way to avoid problems. – David Nov 24 '20 at 21:26
  • @user253751 there's no way to count the LEDs ... not quite correct ... you can monitor the data output of the last LED ... you would only need to do that once – jsotola Nov 24 '20 at 23:40

0 Answers0