void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");
}

float number;

void loop() { 
  Serial.println("Please enter a radius: ");
  if (Serial.available() > 0) {
      number = Serial.parseFloat();
      Serial.print("You entered: ");
      Serial.println(number);
  }

  delay(5000); // slow down printing
}