unsigned long time1;
unsigned long time2 = 0;
const int led = 14;
int pot = 12;  
int wait;
boolean light = false;

void setup() {
  pinMode(led, OUTPUT);
  pinMode(pot, INPUT);
}

void loop() {
  time1 = millis();
  wait = map(analogRead(pot), 0, 1023, 10, 500);
  if ((time1 - time2) >= wait) {
    time2 = time1;
    light = !light;
    digitalWrite(led, light);
  }
}