cloud.ino

#include <Adafruit_NeoPixel.h>

// Which pin on the Arduino is connected to the NeoPixels?
#define PIN            6

// How many NeoPixels are attached to the Arduino?
#define NUM_LEDS      60

// How much the light should dim per loop
#define falloff       1

// How much each "spread" should dim
#define spreadFalloff 40

// Delay between each loop
#define delayval       1

int leds[NUM_LEDS];
int ledsUpdate[NUM_LEDS];

Adafruit_NeoPixel strip = Adafruit_NeoPixel(NUM_LEDS, PIN, NEO_GRB + NEO_KHZ800);

void setup() {
  Serial.begin(9600);
  Serial.println("setup_thunder");
  for(int i=0; i < NUM_LEDS; i++){
     leds[i] = 0;
     ledsUpdate[i] = 0;
  }
  
  strip.begin();
}

void loop() {
  int r = random(1, 200);
    
  if (r == 1) {
    int l = random(0, NUM_LEDS);
    leds[l] = 255;
  }
  
  // Save current value
  memcpy(ledsUpdate, leds, sizeof(leds));
  
  // Update values
  for(int i = 0; i < NUM_LEDS; i++){
    int nextLed = i + 1;
    int previousLed = i - 1;
    int newValue = leds[i] - spreadFalloff;
    
    if (nextLed >= NUM_LEDS) {
      nextLed = 0;
    }
    
    if (previousLed <= 0) {
      previousLed = NUM_LEDS;
    }
    
    if (ledsUpdate[previousLed] < newValue) {
      ledsUpdate[previousLed] = newValue;
    }
  
    if (ledsUpdate[i] < leds[i]) {
      ledsUpdate[i] = leds[i]; 
    }
      
    if (ledsUpdate[nextLed] < newValue) {
      ledsUpdate[nextLed] = newValue;
    }
  }
  
  // Remove negative numbers
  for(int i=0;i<NUM_LEDS;i++){
    ledsUpdate[i] = ledsUpdate[i] - falloff;

    if (ledsUpdate[i] < 0) {
      ledsUpdate[i] = 0;
    }
    if (leds[i] < 0) {
      leds[i] = 0;
    }
  }
  
  // Save updated numbers
  memcpy(leds, ledsUpdate, sizeof(ledsUpdate));
  
  /*
  for(int i=0;i<NUM_LEDS;i++){
    int value = ledsUpdate[i];
    if (value < 10 && value >= 0) {
      Serial.print(0);      
    }
    Serial.print(value);
    Serial.print(", ");
  }
  Serial.print("        ");
  for(int i=0;i<NUM_LEDS;i++){
    int value = leds[i];
    if (value < 10 && value >= 0) {
      Serial.print(0);      
    }
    Serial.print(value);
    Serial.print(", ");
  }
  Serial.println("");
  */
  
  // Show it
  for(int i=0;i<NUM_LEDS;i++){
    int value = leds[i];
    strip.setPixelColor(i, strip.Color(value / 4, 0, value));
  }
  
  strip.show();
  delay(delayval);
}