/* HC-SR04 Ping distance sensor VCC to Arduino 5V GND to Arduino GND Echo to Arduino pin 13 Trig to Arduino pin 12 More info at: http://goo.gl/kJ8Gl Original code improvements to the Ping sketch sourced from Trollmaker.com Some code and wiring inspired by http://en.wikiversity.org/wiki/User:Dstaub/robotcar Modified by Tolson Winters (Aug 27, 2014) for simplified serial monitor reading. */ #define trigPin 12 #define echoPin 13 void setup() { Serial.begin (9600); pinMode(trigPin, OUTPUT); pinMode(echoPin, INPUT); } void loop() { long duration, distance; digitalWrite(trigPin, LOW); delayMicroseconds(2); digitalWrite(trigPin, HIGH); delayMicroseconds(10); digitalWrite(trigPin, LOW); duration = pulseIn(echoPin, HIGH); distance = (duration/2) / 29.1; if (distance >= 400 || distance <= 2){ Serial.println("Out of range"); } else { Serial.print(distance); Serial.println(" cm"); } delay(500); }