obstacle avoiding car

Hello there,

I am a beginner at Arduino and I am making an obstacle avoiding car. everything works fine in my car except that only one wheel works and I can't identify the issue. I have taken the move forward function and put it in a new program and both motors worked fine but when I put it with my whole code only the left motor works. Thank you for your help.

#include <Servo.h>


Servo servo_A1;
int distanceRight = 0;
int distanceLeft = 0;
const int Motor1Forward = 7; // pins for motors
const int Motor1Backward = 6;
const int Motor2Forward = 5;
const int Motor2Backward = 4;
const int ENA = 9; // pins for motor speed control for both
const int ENB = 3;

int trigPin = 11;  // Trigger
int echoPin = 10; // Echo

long duration, distance, leftDistance, rightDistance;


void setup() { // setups up 6 pins to be output pins

pinMode(Motor1Forward, OUTPUT);
pinMode(Motor1Backward, OUTPUT);
pinMode(Motor2Forward, OUTPUT);
pinMode(Motor2Backward, OUTPUT);
pinMode(ENA, OUTPUT);
pinMode(ENB, OUTPUT);
//Serial Port begin
Serial.begin (9600);
//Define inputs and outputs
pinMode(trigPin, OUTPUT);
pinMode(echoPin, INPUT);
servo_A1.attach(A1);

}

void loop(){
  scan();
  servo_A1.write(120);
  delay(250);


  if (distance <= 20) {
  Stop();
  delay(800);
  moveBackward();
  delay(800);
  Stop();
  delay(200);
  lookRight();
  delay(50);
  scan();
  rightDistance = distance;
  delay(500);

  lookLeft();
  delay(50);
  scan();
  leftDistance = distance;
  delay(500);
  if (rightDistance >= leftDistance) {
      moveRight();
      delay(500);
  } else {
      moveLeft();
      delay(500);
  }
}
   else {
  moveForward();
  }

}


void lookRight() {
  servo_A1.write(60);
  delay(1000);
  servo_A1.write(120);
  return;
}
void lookLeft(){
  servo_A1.write(255);
  delay(1000);
  servo_A1.write(120);
  return;
}
void moveForward() {

digitalWrite(Motor1Forward, HIGH); //Motor A will go forward

digitalWrite(Motor1Backward, LOW);

analogWrite(ENA, 200); // Max speed. You can set a speed of a motor from 0 to 255


digitalWrite(Motor2Forward,HIGH);

digitalWrite(Motor2Backward,LOW);

analogWrite(ENB, 200); // Notice that the speeds of your two motors are

}

void Stop() {
  digitalWrite(Motor1Forward, LOW); //Motor A will stop
  digitalWrite(Motor1Backward, LOW);

  analogWrite(ENA, 0);

  digitalWrite( Motor2Forward,LOW);  //Motor A will stop
  digitalWrite( Motor2Backward,LOW);

  analogWrite(ENB, 0);   
}
void moveBackward() {
  digitalWrite(Motor1Forward, LOW); //Motor A will go backward
  digitalWrite(Motor1Backward, HIGH);
  analogWrite(ENA, 150);
  digitalWrite( Motor2Forward,LOW);  //Motor B will go backward
  digitalWrite( Motor2Backward,HIGH);

  analogWrite(ENB, 120);
}
void moveLeft() {
  digitalWrite(Motor1Forward, HIGH); //Motor A will go forward
  digitalWrite(Motor1Backward, LOW);

  analogWrite(ENA, 220); // Max speed. You can set a speed of a motor from 0 to 255
    
  digitalWrite( Motor2Forward,LOW);  //Motor B will go backward
  digitalWrite( Motor2Backward,HIGH);

  analogWrite(ENB, 125);   

}
void moveRight() {
  digitalWrite(Motor1Forward, LOW); //Motor A will go Backward
  digitalWrite(Motor1Backward, HIGH);

  analogWrite(ENA, 220); // Max speed. You can set a speed of a motor from 0 to 255

  digitalWrite( Motor2Forward,HIGH);  //Motor A will go forward
  digitalWrite( Motor2Backward,LOW);

  analogWrite(ENB, 125);  
}
void scan() {
 
  // The sensor is triggered by a HIGH pulse of 10 or more microseconds.
  // Give a short LOW pulse beforehand to ensure a clean HIGH pulse:
  digitalWrite(trigPin, LOW);
  delayMicroseconds(5);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
 
  // Read the signal from the sensor: a HIGH pulse whose
  // duration is the time (in microseconds) from the sending
  // of the ping to the reception of its echo off of an object.
  pinMode(echoPin, INPUT);
  duration = pulseIn(echoPin, HIGH);
  // Convert the time into a distance
  distance = (duration/2) / 29.1;   // Divide by 29.1 or multiply by 0.0343
  // Serial.print(distance);
  // Serial.print("cm");
  // Serial.println();
}

sketch_oct28a.ino (3.83 KB)

Congratulations on using code tags on your first post, karma++

Unfortunately using Servo.h disables PWM (analogWrite) on pins 9 and 10 on most Arduinos so you'll have to choose another pin for ENA.

It is documented in https://www.arduino.cc/en/reference/servo

Steve

thank you very much I am using Arduino UNO and I will try changing the pins of my ena and enb