int trig= 7;
int echo= 6;
int led= 13;
void setup() {
// initialize serial communication:
Serial.begin(9600);
pinMode(trig, OUTPUT);
pinMode(echo, INPUT);
pinMode(led, OUTPUT);
}
void loop()
{
digitalWrite(trig, LOW);
delayMicroseconds(2);
digitalWrite(trig, HIGH);
delayMicroseconds(10);
digitalWrite(trig, LOW);
long val= pulseIn(echo, HIGH) * 17 / 100;
Serial.println(val);
if(val < 50) {
//5cm 범위 안에들어오면 LED 점등
digitalWrite(led, HIGH);
} else {
digitalWrite(led, LOW);
}
delay(100);
}