#include <SoftwareSerial.h>   

SoftwareSerial mySerial(0, 1); // RX, TX

int Yellow = 5;  // PA5 MISO YELLOW
int WHITE = 4;  // PA4 SCK  WHITE
int RED = 6;  // PA6 MOSI BUZZER/RED

int trig = 7; // PA7 > 6 Trig
int echo = 8; // PB2 > 5 Echo

long duration, distance;

int cm = 0;

void setup()
{
  Serial.begin(9600);
  Serial.println("Serial Started...");

  pinMode(echo, INPUT);
  pinMode(trig, OUTPUT);

  pinMode(Yellow, OUTPUT);
  pinMode(WHITE, OUTPUT);
  pinMode(RED, OUTPUT);
}

void loop()
{
  digitalWrite(trig, LOW);
  digitalWrite(trig, HIGH);
  digitalWrite(trig, LOW);

  int duration = pulseIn (echo, HIGH);
  cm = duration * 0.034 / 2;

  //Serial.println(cm);

  if (cm >= 30)
  {
    digitalWrite(Yellow, LOW);
    digitalWrite(WHITE, LOW);
    digitalWrite(RED, LOW);
    delay(1000);
    digitalWrite(Yellow, HIGH);
    digitalWrite(WHITE, LOW);
    digitalWrite(RED, LOW);
    delay(1000);
  }

  else if (cm < 30 && cm > 15)
  {
    digitalWrite(Yellow, LOW);
    digitalWrite(WHITE, LOW);
    digitalWrite(RED, LOW);
    delay(500);
    digitalWrite(Yellow, LOW);
    digitalWrite(WHITE, HIGH);
    digitalWrite(RED, LOW);
    delay(500);
  }

  else if (cm < 15 && cm > 5)
  {
    digitalWrite(Yellow, LOW);
    digitalWrite(WHITE, LOW);
    digitalWrite(RED, LOW);
    delay(250);
    digitalWrite(Yellow, LOW);
    digitalWrite(WHITE, LOW);
    digitalWrite(RED, HIGH);
    delay(250);
  }

  else if (cm <= 5)
  {
    digitalWrite(Yellow, LOW);
    digitalWrite(WHITE, LOW);
    digitalWrite(RED, HIGH);
    delay(100);
  }
}