Measuring Distance using Ultrasonic sensor

1#include <NewPing.h>
2
3#define TRIGGER_PIN  12  // Arduino pin tied  to trigger pin on the ultrasonic sensor.
4#define ECHO_PIN     11  // Arduino  pin tied to echo pin on the ultrasonic sensor.
5#define MAX_DISTANCE 200 // Maximum  distance we want to ping for (in centimeters). Maximum sensor distance is rated  at 400-500cm.
6
7NewPing sonar(TRIGGER_PIN, ECHO_PIN, MAX_DISTANCE); // NewPing  setup of pins and maximum distance.
8
9void setup() {
10  Serial.begin(115200);  // Open serial monitor at 115200 baud to see ping results.
11}
12
13void loop()  {
14  delay(50);                     // Wait 50ms between pings (about 20 pings/sec).  29ms should be the shortest delay between pings.
15  Serial.print("Ping: ");
16  Serial.print(sonar.ping_cm()); // Send ping, get distance in cm and print result  (0 = outside set distance range)
17  Serial.println("cm");
18}