#define ECHO_PIN 2
#define TRIG_PIN 3
void setup()
{
Serial.begin(115200);
pinMode(LED_BUILTIN,OUTPUT);
pinMode(TRIG_PIN,OUTPUT);
pinMode(ECHO_PIN, INPUT);
}
float readDistanceCM()
{
digitalWrite(TRIG_PIN,LOW);
delayMicroseconds(2);
digitalWrite(TRIG_PIN,HIGH);
delayMicroseconds(10);
digitalWrite(TRIG_PIN,LOW);
int duration=pulseIn(ECHO_PIN,HIGH);
return duration*0.034*2;
}
void loop()
{
float distance=readDistanceCM();
bool isNearby=distance>100;
digitalWrite(LED_BUILTIN,isNearby);
Serial.print("Measured distance:");
Serial.println(readDistanceCM());
delay(100);
}