const int PM = 34;
const int LED = 23;
void setup() {
  Serial.begin(115200);
  pinMode(LED, OUTPUT);
}void loop() {
  int PMvalue = analogRead(PM);
  Serial.print("potentiometer value: ");
  Serial.println(PMvalue);
  int Lbright = map (PMvalue, 0, 4095, 0, 255);
  analogWrite(LED, Lbright);
  delay(500);
}