Project_11174_Code

#define relay     5
#define irSensor  4
#define trigPin   3
#define echoPin   2

long duration;
int Distance;
int sensorState = 0;
int moveFlag = 0;

void setup() {
  Serial.begin(9600);
  pinMode(relay, OUTPUT);
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(irSensor, INPUT);
  digitalWrite(relay, 1);
  digitalWrite(trigPin, 0);
  moveFlag = 0;

}
void loop() {
  IR();
  US();
  if (moveFlag) {
    digitalWrite(relay, 0);
    if (Distance>20) {
      digitalWrite(relay, 1);
    }
  }

}

void US() {
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  duration = pulseIn(echoPin, HIGH);
  Distance = duration * 0.034 / 2;
  Serial.print("Distance: ");
  Serial.println(Distance);
}

void IR() {
  sensorState = digitalRead(irSensor);
  Serial.println(sensorState);
  if (!sensorState) {
    moveFlag = 1;
  }
}