ultrasonic sensor for distance

day03/07_ultrasonic/07_ultrasonic.ino

+const byte ECHO = 6;
+const byte TRIGGER = 5;
+
+void setup() {
+	Serial.begin(9600);
+	pinMode(ECHO, INPUT);
+	pinMode(TRIGGER, OUTPUT);
+}
+
+void loop() {
+	digitalWrite(TRIGGER, HIGH);
+	delayMicroseconds(10);
+	digitalWrite(TRIGGER, LOW);
+	unsigned long rawdata = pulseIn(ECHO, HIGH);
+	Serial.print(0.017 * rawdata);
+	Serial.println(" cm");
+	delay(100);
+}