int vr1 = 13;
int value1 =0;
int led1 = 16;
int led2 = 17;
int led3 = 5;
int led4 = 18;
void setup() {
 Serial.begin(9600);
  pinMode (led1, OUTPUT);
  pinMode (led2, OUTPUT);
  pinMode (led3, OUTPUT);
  pinMode (led4, OUTPUT);
}

void loop() {
  delay(100);
 value1= analogRead(vr1);
 Serial.println(value1);

 if (value1 >=3500){
  digitalWrite(led1, 1);
  digitalWrite(led2, 1);
  digitalWrite(led3, 1);
  digitalWrite(led4, 1);
 } else if (value1 >=2500){
  digitalWrite(led1, 1);
  digitalWrite(led2, 1);
  digitalWrite(led3, 1);
  digitalWrite(led4, 0);
 }else if (value1 >=1500){
  digitalWrite(led1, 1);
  digitalWrite(led2, 1);
  digitalWrite(led3, 0);
  digitalWrite(led4, 0);
 }else if (value1 >=500){
  digitalWrite(led1, 1);
  digitalWrite(led2, 0);
  digitalWrite(led3, 0);
  digitalWrite(led4, 0);
 }else if (value1 >=0){
  digitalWrite(led1, 0);
  digitalWrite(led2, 0);
  digitalWrite(led3, 0);
  digitalWrite(led4, 0);
 }

}