framework-arduinoteensy-cxx20/libraries/WS2812Serial/examples/FastLED_Cylon/FastLED_Cylon.ino

// FastLED Cylon Example, using Non-Blocking WS2812Serial

#include <WS2812Serial.h>
#define USE_WS2812SERIAL
#include <FastLED.h>

// How many leds in your strip?
#define NUM_LEDS 64

// Usable pins:
//   Teensy LC:   1, 4, 5, 24
//   Teensy 3.2:  1, 5, 8, 10, 31   (overclock to 120 MHz for pin 8)
//   Teensy 3.5:  1, 5, 8, 10, 26, 32, 33, 48
//   Teensy 3.6:  1, 5, 8, 10, 26, 32, 33
//   Teensy 4.0:  1, 8, 14, 17, 20, 24, 29, 39
#define DATA_PIN 1

// Define the array of leds
CRGB leds[NUM_LEDS];

void setup() {
	Serial.begin(57600);
	Serial.println("resetting");
	LEDS.addLeds<WS2812SERIAL,DATA_PIN,RGB>(leds,NUM_LEDS);
	LEDS.setBrightness(84);
}

void fadeall() { for(int i = 0; i < NUM_LEDS; i++) { leds[i].nscale8(250); } }

void loop() {
	static uint8_t hue = 0;
	Serial.print("x");
	// First slide the led in one direction
	for(int i = 0; i < NUM_LEDS; i++) {
		// Set the i'th led to red
		leds[i] = CHSV(hue++, 255, 255);
		// Show the leds
		FastLED.show();
		// now that we've shown the leds, reset the i'th led to black
		// leds[i] = CRGB::Black;
		fadeall();
		// Wait a little bit before we loop around and do it again
		delay(20);
	}
	Serial.print("x");

	// Now go in the other direction.
	for(int i = (NUM_LEDS)-1; i >= 0; i--) {
		// Set the i'th led to red
		leds[i] = CHSV(hue++, 255, 255);
		// Show the leds
		FastLED.show();
		// now that we've shown the leds, reset the i'th led to black
		// leds[i] = CRGB::Black;
		fadeall();
		// Wait a little bit before we loop around and do it again
		delay(20);
	}
}