drip.cpp

#include "Arduino.h"

#include <Adafruit_NeoPixel.h>

#define PIN 4
#define LED_COUNT 60

// Create an instance of the Adafruit_NeoPixel class called "leds".
// That'll be what we refer to from here on...
Adafruit_NeoPixel leds = Adafruit_NeoPixel(LED_COUNT, PIN, NEO_GRB + NEO_KHZ800);

#define PT_COUNT 5

struct pt {
    byte r;
    byte g;
    byte b;
    int p;
    int dir;
    int speed;
};

pt points[PT_COUNT];

void pt_init(pt *point) {
    byte brightness = random(0,10) * 10;
    point->r = brightness;
    point->g = brightness;
    point->b = brightness + random(0,10) * 10;;
    point->p = LED_COUNT + random(0, 10);
    point->dir = -1;
    point->speed = random(1,5);
}

void pt_update(pt *point) {
    leds.setPixelColor(point->p, point->r, point->g, point->b);
    point->p += point->dir * point->speed;
    if (point->p < 0) {
        pt_init(point);
    }
}

void setup()
{
  leds.begin();  // Call this to start up the LED strip.
  randomSeed(analogRead(0));
  for(int i=0; i< PT_COUNT; i++) {
    pt_init(&points[i]);
  }
}


void loop()
{
  // Ride the Rainbow Road
    for (int i=0; i<=LED_COUNT-1; i++) {
        leds.setPixelColor(i, 0, 0, 0);
    }

    for (int i=0; i<PT_COUNT; i++) {
        pt_update(&points[i]);
    }

    leds.show();
    delay(40);
}