int potval;
int dt=100;
int potpin=A0;
int redpin=7;
void setup() {
  // put your setup code here, to run once:
Serial.begin(115200);
pinMode(potpin, INPUT);
pinMode(redpin, OUTPUT);

}

void loop() {
potval=analogRead(potpin);
Serial.println(potval);
delay(dt);

while (potval>900) {
  digitalWrite(redpin, HIGH);
  potval=analogRead(potpin);
  Serial.println(potval);
  delay(dt);
}
digitalWrite(redpin, LOW);
}