#define echo 2
#define trig 3
/*#define relay1 4
#define relay2 5
#define relay3 6
#define relay4 7
#define relay5 8*/
int relayPins[5] = { 4, 5, 6,7,8};
void setup() {
Serial.begin(9600);
pinMode(echo, INPUT);
for( int i=3;i<=8;i++){
  pinMode(i, OUTPUT);
}
}

void loop() {
digitalWrite(trig, LOW);
delayMicroseconds(10);
digitalWrite(trig, HIGH);
delayMicroseconds(10);
digitalWrite(trig, LOW);
int dis=pulseIn(echo,HIGH);
int distance=((dis/2)*0.034);
int n=map(distance,0,400,1,5);
Serial.println(distance);
delay(1000);
for (int i = 0; i < 5; i++) {
    if (i < n) {
      digitalWrite(relayPins[i], LOW); // Activate relay
    } else {
      digitalWrite(relayPins[i], HIGH); // Deactivate relay
    }
  }}