Basic snake ping ponging along a 30 led strip

main.cpp

#include <Arduino.h>
#include <FastLED.h>

#define NUM_LEDS 30
#define MILLIS_PER_FRAME 33
#define FRAMES_PER_SECOND 30;

CRGB leds[NUM_LEDS];

int frame = 0;
bool forward = true;


void allColor(CRGB color) {
	for(int i = NUM_LEDS; i--;) {
		leds[i] = color;
	}
}

void clear() {
	allColor(CRGB::Black);
}

void white() {
	allColor(CRGB::White);
}

void snake(int start, int length) {
	for(int i = 0; i < length; i++) {
		leds[i + start] = CRGB::White; FastLED.show();
	}
}

void setup() { 
	FastLED.addLeds<DOTSTAR>(leds, NUM_LEDS);
}

void loop() {
	clear();
	FastLED.show();
	snake(frame, 3);
	delay(MILLIS_PER_FRAME);
	if (forward) frame++;
	if (!forward) frame--;
	if (frame == 30 - 3 || frame == 0) forward = !forward;
}