#define ECHO_PIN 41
#define TRIG_PIN 40
#define LED 33
#define LED2 34

void setup() {
 pinMode(LED, OUTPUT);
 pinMode(LED2, OUTPUT);
 pinMode(ECHO_PIN, INPUT);
 pinMode(TRIG_PIN, OUTPUT);
}

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();
if (distance<100) {
digitalWrite(LED2, HIGH);
digitalWrite(LED, LOW);
}else{
digitalWrite(LED2, LOW);
digitalWrite(LED, HIGH);
}
}