int analog_pin = 7;
int led_Red = 7;
int led_Yellow = 8;
int led_Green = 9;
float val;
float volt;

void setup() {
  pinMode(led_Red, OUTPUT);
  pinMode(led_Yellow, OUTPUT);
  pinMode(led_Green, OUTPUT);

}

void loop() {
  val = analogRead(analog_pin);
  volt = val*5/1024;

  if(volt<0.05){

    delay(250);
    digitalWrite(led_Red, LOW);
    digitalWrite(led_Yellow, LOW);
    digitalWrite(led_Green, LOW);
    delay(250);
  }else{
    
     analogWrite(led_Red, volt*50);
    if (val>345){
      analogWrite(led_Yellow, volt*50);
    }
    if (val>682){
      analogWrite(led_Green, volt*50);
    }
  }
  
}