void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  Serial.println("testing of potentiometer!");
  pinMode(A0, INPUT);
  pinMode(D7,OUTPUT);
}

void loop() {
  int t= analogRead(A0);
  if (t>800 && t<1024){
digitalWrite(D7,HIGH);
  }
  else {
    digitalWrite(D7,LOW);
  }
 Serial.println(t);
}