HC-SR04 Ultrasonic Sensor Simple Project

Projects General Guidance
11

Did that. -1 indicates that range is out of bounds. Take a look

if (distance >= maximumRange || distance <= minimumRange){
 /* Send a negative number to computer and Turn LED ON 
 to indicate "out of range" */
 Serial.println("-1");
 digitalWrite(LEDPin, HIGH); 
 }

while I watch at the serial monitor i wave my hand and no nothing happens. It keep showing -1.

PS. I am currently not using the processing IDE. I am working and trying to debug only on arduino IDE. So everything i said is about the arduino IDE.