void setup() {
pinMode(LED_BUILTIN, OUTPUT);
Serial.begin(9600);
}
void loop() {
String readString;
String Q;
if (Serial.available() > 0) {
// int state = Serial.read();
char c = Serial.read();
if (c == '0') {
digitalWrite(LED_BUILTIN, HIGH);
Serial.println("LED OFF");
}
if (c == '1' ) {
digitalWrite(LED_BUILTIN, LOW);
Serial.println("LED ON");
}
}
delay(50);
}