#define R 7
#define G 5
#define B 3

#define TRIG_PIN 13
#define ECHO_PIN 12
byte r_level;
byte g_level;
byte b_level=0;
bool blue_state=0;
unsigned long migalka=200;
unsigned long migalka_time;
void setup() {
  Serial.begin(9600);
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(R,OUTPUT);
  pinMode(G,OUTPUT);
  pinMode(B,OUTPUT);
}
long time, distance; 
void loop() {
  digitalWrite(TRIG_PIN, LOW); 
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);

  time = pulseIn(ECHO_PIN, HIGH);

  distance = (time / 2) * 0.0343;
  if(distance<=250 && distance!=0)
  {
    r_level= 255 - distance;
    g_level=distance;
    b_level=0;
  }
  else
  {
    r_level=0;
    g_level=0;
    b_level=255;
  }
  if(!b_level)
  {
    analogWrite(R,r_level);
    analogWrite(G,g_level);
    analogWrite(B,b_level);
  }
  else
  {
    if(millis()>=migalka_time+migalka)
    {
      migalka_time=millis();
      blue_state=!blue_state;
    }
    analogWrite(R,r_level);
    analogWrite(G,g_level);
    analogWrite(B,b_level*blue_state);
  }
  Serial.print(distance);
  Serial.print('\t');
  Serial.print(r_level);
  Serial.print('\t');
  Serial.print(g_level);
  Serial.print('\t');
  Serial.println(b_level);
  
}