int sensor=A0;
int LEDred=9;
int LEDyellow=10;
int LEDgreen=11;
int buzPin1=8;
int val=0;

void setup() {
  // put your setup code here, to run once:
pinMode(LEDred , OUTPUT);
pinMode(LEDyellow, OUTPUT);
pinMode(LEDgreen, OUTPUT);
pinMode(buzPin1, OUTPUT);
pinMode(sensor , INPUT);
Serial.begin(9600);
}

void loop() {
  // put your main code here, to run repeatedly:
val=analogRead(sensor);
if (val>=150){
  digitalWrite(LEDred, HIGH);
  tone(buzPin1, val);
  digitalWrite(LEDyellow, LOW);
  digitalWrite(LEDgreen, LOW);
  delay(val);
}
else if (val>=250){
  digitalWrite(LEDyellow, HIGH);
  tone(buzPin1, val);
  digitalWrite(LEDred, LOW);
  digitalWrite(LEDyellow, LOW);
  delay(val);
}
else (val>=350);{
  digitalWrite(LEDgreen, HIGH);
  tone(buzPin1, val);
  digitalWrite(LEDred, LOW);
  digitalWrite(LEDyellow, LOW);
  delay(val);
}
float voltage=val*(5.0/1023.0);

Serial.println(voltage);
}