According to Paul Stoffregen’s Articles on December 6, 2017December 7, 2017, we know the APA102 LEDs strips have the problem at 24 MHz, usually after 150 to 250 LEDs.
But why? Here’s his attempt to investigate:One tempting explanation is signal quality problems due to horribly messy unterminated wiring carrying high speed signals, as in this photo!
But it turned out to be a more fundamental timing problem.In this test, a Teensy 3.2 runs the FastLED “Cylon” example with this line:LEDS.addLeds<APA102,11,13,RGB,DATA_RATE_MHZ(24)>(leds,NUM_LEDS);NUM_LEDs was set to [...]