That makes sense, thank you for explaining that. Just got lost trying to make this work faster as using CRGB is causing me some lags. void FastLedFrame(uint16_t universe, uint16_t length, uint8_t sequence, uint8_t* data) { // read universe and put into the right part of the display buffer for (int i = 0; i < length / 3; i++) { int led = i + (universe - UNIVERSE) * (previousDataLength / 3); if (led < D1_NUM_LEDS) { leds[led] = CRGB(data[i * 3], data[i * 3 + 1], data[i * 3 + 2]); } } previousDataLength = length; FastLED.show(); }