code.ino

#define enA 3 //enable pin of motor a
#define in1 8 // left pin of motor a
#define in2 7 // right pin of motor a
#define enB 5
#define in3 6
#define in4 4
#define trigPin 12
#define echoPin 13
int motorSpeedA = 0;
int motorSpeedB = 0;
long duration;
int distance;
void setup() {
  // put your setup code here, to run once:
  pinMode(enA, OUTPUT);
  pinMode(enB, OUTPUT);
  pinMode(in1, OUTPUT);
  pinMode(in2, OUTPUT);
  pinMode(in3, OUTPUT);
  pinMode(in4, OUTPUT);
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  // Begin Serial communication at a baudrate of 9600:
  Serial.begin(9600);
}
void loop() {
  // clear the trigPin by setting it LOW:
  digitalWrite(trigPin, LOW);
  delayMicroseconds(5);
  // Trigger the sensor by setting the trigPin high for 10 microseconds:
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  //Read the echoPin, pulseIn() returns the duration in microseconds:
  duration = pulseIn(echoPin, HIGH);
  //Calculate the distance:
  distance = duration*0.034/2;
  //Print the distance on the Serial Monitor (Ctrl+Shift+M)
  Serial.print("Distance = ");
  Serial.print(distance);
  Serial.println("cm");
   if (distance < 10) {
    digitalWrite(in1, HIGH); // turn left pin of motor a to high
    digitalWrite(in2, LOW); // turn right pin of motor a to high
    analogWrite(enA, 150); // set speed of motor A
    digitalWrite(in3, LOW); // turn left pin of motor b to low
    digitalWrite(in4, HIGH); // turn right pin of motor b to high
    analogWrite(enB, 150); // set speed of motor B
    }
    else {
    digitalWrite(in1, HIGH); // turn left pin of motor a to high
   digitalWrite(in2, LOW); // turn right pin of motor a to low
    analogWrite(enA, 150); // set speed of motor A
    digitalWrite(in3, HIGH); // turn left pin of motor b to high
    digitalWrite(in4, LOW); // turn right pin of motor b to low
    analogWrite(enB, 150); // set speed of motor B
     }
}