Just downloaded FastSPI2 for the first time (RC3). I’m trying to control 5m of WS2811 pixels and getting some flickering at the in the last ~20 pixels. I have 5V/GND/data at one end and 5V/gnd connected at the other end, which makes me think it’s a data line problem. Shouldn’t I be able to send data this far without flicker or am I missing something?
What are you using as a controller?
Also - sometimes, with longer lengths of ws2811’s, I have found some help in grounding the data line at the far end of the strip (just connecting data to ground).
… or run it through a series resistor like what I ended up doing with my LPD8806s … tying them to ground didn’t fix the problem, but the series resistor did.
I’m using a Teensy 3.0. I had put a 100 ohm resister in series with the data line but hadn’t connected data to ground. Thanks for the suggestion, that fixed it!
Yeah, it’s probably different for each driver. I too started with simply connecting the data and clock lines to ground at the end of the string, but that actually made it worse. In a normal scenario, there should be resistors in series with those lines when you reach a certain length and then connect them to the next string. So since I’m not connecting to “the next string”, I pulled them down to ground with the resistors. That solved the problem.