Attiny 85 Feuer

Ein kleines Lagerfeuer gesteuert von einem Attiny 85 und einer drei Farben LED WS2812. Das Feuer beziehungsweise die LED lodert per Zufallsgenerator in verschiedenen Farben, um so eine ziemlich echte Wirkung von einem Feuer zu imitieren.

#include <Adafruit_NeoPixel.h>

// data pin
#define PIN 0
// led count
#define CNT 20

// Parameter 1 = number of pixels in strip
// Parameter 2 = pin number (most are valid)
// Parameter 3 = pixel type flags, add together as needed:
//   NEO_RGB     Pixels are wired for RGB bitstream
//   NEO_GRB     Pixels are wired for GRB bitstream
//   NEO_KHZ400  400 KHz bitstream (e.g. FLORA pixels)
//   NEO_KHZ800  800 KHz bitstream (e.g. High Density LED strip)
Adafruit_NeoPixel strip = Adafruit_NeoPixel(CNT, PIN, NEO_GRB + NEO_KHZ800);

uint32_t fire_color   = strip.Color ( 160,  28,  00); //original: 60,35,00
uint32_t off_color    = strip.Color (  0,  0,  0);

///
/// Fire simulator
///
class NeoFire
{
  Adafruit_NeoPixel &strip;
 public:

  NeoFire(Adafruit_NeoPixel&);
  void Draw();
  void Clear();
  void AddColor(uint8_t position, uint32_t color);
  void SubstractColor(uint8_t position, uint32_t color);
  uint32_t Blend(uint32_t color1, uint32_t color2);
  uint32_t Substract(uint32_t color1, uint32_t color2);
};

///
/// Constructor
///
NeoFire::NeoFire(Adafruit_NeoPixel& n_strip)
: strip (n_strip)
{
}

///
/// Set all colors
///
void NeoFire::Draw()
{
Clear();

for(int i=0;i<CNT;i++)
  {
  AddColor(i, fire_color);
  int r = random(80);
  uint32_t diff_color = strip.Color ( r, r/2, r/2);
  SubstractColor(i, diff_color);
  }
  
strip.show();
}

///
/// Set color of LED
///
void NeoFire::AddColor(uint8_t position, uint32_t color)
{
uint32_t blended_color = Blend(strip.getPixelColor(position), color);
strip.setPixelColor(position, blended_color);
}

///
/// Set color of LED
///
void NeoFire::SubstractColor(uint8_t position, uint32_t color)
{
uint32_t blended_color = Substract(strip.getPixelColor(position), color);
strip.setPixelColor(position, blended_color);
}

///
/// Color blending
///
uint32_t NeoFire::Blend(uint32_t color1, uint32_t color2)
{
uint8_t r1,g1,b1;
uint8_t r2,g2,b2;
uint8_t r3,g3,b3;

r1 = (uint8_t)(color1 >> 16),
g1 = (uint8_t)(color1 >>  8),
b1 = (uint8_t)(color1 >>  0);

r2 = (uint8_t)(color2 >> 16),
g2 = (uint8_t)(color2 >>  8),
b2 = (uint8_t)(color2 >>  0);

return strip.Color(constrain(r1+r2, 0, 255), constrain(g1+g2, 0, 255), constrain(b1+b2, 0, 255));
}

///
/// Color blending
///
uint32_t NeoFire::Substract(uint32_t color1, uint32_t color2)
{
uint8_t r1,g1,b1;
uint8_t r2,g2,b2;
uint8_t r3,g3,b3;
int16_t r,g,b;

r1 = (uint8_t)(color1 >> 16),
g1 = (uint8_t)(color1 >>  8),
b1 = (uint8_t)(color1 >>  0);

r2 = (uint8_t)(color2 >> 16),
g2 = (uint8_t)(color2 >>  8),
b2 = (uint8_t)(color2 >>  0);

r=(int16_t)r1-(int16_t)r2;
g=(int16_t)g1-(int16_t)g2;
b=(int16_t)b1-(int16_t)b2;
if(r<0) r=0;
if(g<0) g=0;
if(b<0) b=0;

return strip.Color(r, g, b);
}

///
/// Every LED to black
///
void NeoFire::Clear()
{
for(uint16_t i=0; i<strip.numPixels (); i++)
  strip.setPixelColor(i, off_color);
}

NeoFire fire(strip);

///
/// Setup
///
void setup()
{
strip.begin();
strip.show(); // Initialize all pixels to 'off'
}

///
/// Main loop
///
void loop()
{
fire.Draw();
delay(random(3,100));
}