Arduino L293D Obstacle Avoiding Robot

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Introduction: Arduino L293D Obstacle Avoiding Robot

What you need to make it is.

1. Arduino uno.

2. Chassis kit of some sort.

3. L293D Motor driving chip.

4. power supple i used 0.5 mah li-po battery at 7.4v

5. lots of wires

6. ultra sonic distance sensor

7. potentiometer

when you put the code in the robot it will go forward, when the ultra sonic sensor senses something it will reverse and turn left.

Step 1: Wiring

i made this robot with a thin peace of wood 11cm x 11cm

Step 2: Code

int pwm_speed
//trig of ultrasonic sensor
int trig = 12;
//echo of ultrasonic sensor
int echo = 13; 
//int red = 2;
//int blue = 4;
//int green = 7;
int potpin = A0;
void setup() {
//pins for motor controller
pinMode(11, OUTPUT);
pinMode(10, OUTPUT);
pinMode(9, OUTPUT);
pinMode(6, OUTPUT);//pinMode(red,OUTPUT);
//pinMode(blue,OUTPUT);
//pinMode(green,OUTPUT);//set trig as output and echo as input for ultrasonic sensor
pinMode(trig, OUTPUT);
pinMode(echo,INPUT);
}void loop() {
pwm_speed = analogRead(potpin);
pwm_speed = map(pwm_speed, 0, 1028, 0, 225);scan();int duration = pulseIn(echo, HIGH);
int distance = duration / 29 / 2;if(distance > 15){
   forward(100);
}else if(distance < 15){
  backward(700);
  left(500);
}}// function for driving straight
void forward(int delay_time){
  analogWrite(11, pwm_speed);
  analogWrite(10, 0);
  
  analogWrite(9, 0);
  analogWrite(6, pwm_speed);
  delay(delay_time);
}//function for reversing
void backward(int delay_time){
  analogWrite(11, 0);
  analogWrite(10, pwm_speed);
  
  analogWrite(9, pwm_speed);
  analogWrite(6, 0);
  delay(delay_time);
}//function for turning left
void left(int delay_time){
  analogWrite(11, 0);
  analogWrite(10, pwm_speed);
  
  analogWrite(9, 0);
  analogWrite(6, pwm_speed);
  delay(delay_time);
}//function for turning right
void right(int delay_time){
  analogWrite(11, pwm_speed);
  analogWrite(10, 0);
  
  analogWrite(9, pwm_speed);
  analogWrite(6, 0);
  delay(delay_time);
}//function for stopping motors
void motors_stop(int delay_time){
  
  analogWrite(11, 0);
  analogWrite(10, 0);
  
  analogWrite(9, 0);
  analogWrite(6, 0);
  delay(delay_time);
}
void scan(){
digitalWrite(trig, LOW);
delayMicroseconds(2);
digitalWrite(trig, HIGH);
delayMicroseconds(5);
digitalWrite(trig, LOW);
}</p>

Step 3: Touble Shooting

If the robot goes the wrong way swap the motor wires around.

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    user

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    26 Comments

    Hey Robert the code that you have given i the instruction have some errors. pls rectify the errors and post it. Thank you.

    Screen Shot 2016-12-28 at 3.15.42 PM.png

    if you use this code it should work but you'll need to change the motor driver wires to pin 6 int 1 pin 9 int 2 pin 10 int 3 pin 11 int 4 int on the motor driver board and you can use a RGB led with this code and the pot for speed is A0 so the same

    int trig = 12;

    int echo = 13;

    int red = 2;

    int blue = 4;

    int green = 7;

    int val=200;

    int potpin = A0;

    void setup() {

    //pins for motor controller

    pinMode(11, OUTPUT);

    pinMode(10, OUTPUT);

    pinMode(9, OUTPUT);

    pinMode(6, OUTPUT);

    pinMode(red,OUTPUT);

    pinMode(blue,OUTPUT);

    pinMode(green,OUTPUT);

    //set trig as output and echo as input for ultrasonic sensor

    pinMode(trig, OUTPUT);

    pinMode(echo,INPUT);

    }

    void loop() {

    val = analogRead(potpin);

    val = map(val, 0, 1028, 0, 225);

    digitalWrite(trig, LOW);

    delayMicroseconds(2);

    digitalWrite(trig, HIGH);

    delayMicroseconds(5);

    digitalWrite(trig, LOW);

    int duration = pulseIn(echo, HIGH);

    int distance = duration / 29 / 2;

    if(distance > 15){

    digitalWrite(blue,0);

    digitalWrite(red,1);

    forward(50);

    }else if(distance < 15){

    digitalWrite(red,0);

    digitalWrite(blue,1);

    backward(600);

    digitalWrite(red,1);

    digitalWrite(green,0);

    left(700);

    digitalWrite(green,1);

    }

    }

    // function for driving straight

    void forward(int delay_time){

    analogWrite(11, val);

    digitalWrite(10, LOW);

    analogWrite(9, val);

    digitalWrite(6, LOW);

    delay(delay_time);

    }

    //function for reversing

    void backward(int delay_time){

    digitalWrite(11, LOW);

    analogWrite(10, val);

    digitalWrite(9, LOW);

    analogWrite(6, val);

    delay(delay_time);

    }

    //function for turning left

    void left(int delay_time){

    analogWrite(11, val);

    digitalWrite(10, LOW);

    digitalWrite(9, LOW);

    analogWrite(6, val);

    delay(delay_time);

    }

    //function for turning right

    void right(int delay_time){

    digitalWrite(11, LOW);

    analogWrite(10, val);

    analogWrite(9, val);

    digitalWrite(6, LOW);

    delay(delay_time);

    }

    //function for stopping motors

    void motors_stop(int delay_time){

    digitalWrite(11, LOW);

    digitalWrite(10, LOW);

    digitalWrite(9,LOW);

    digitalWrite(6, LOW);

    delay(delay_time);

    }

    this codes are having error can u have another codes

    problem with the code :(

    sketch_may08a.ino:5:16: error: expected unqualified-id before '<' token

    sketch_may08a.ino:10:8: error: expected constructor, destructor, or type conversion before '(' token

    sketch_may08a.ino:11:8: error: expected constructor, destructor, or type conversion before '(' token

    sketch_may08a.ino:12:8: error: expected constructor, destructor, or type conversion before '(' token

    Hello about the L293D motor IC what are the other replacement for it.? I mean, there is no available stock of the said IC and im going to use it im project arduino and bluetooth car. So, is there other value of IC as replacement for it.?
    Any help would be greatly appreciated, thank you.

    Try this from Sparkfun, the SN754410 Quad Half H-Bridge. https://www.sparkfun.com/products/315

    We have a problem. We can't find the name of the supersonic sensor . Can you give us name or can we use another one?

    If you Google HC-SR04, you will find an ample list of retailers/supply - especially eBay

    user

    Great project! I have to ask if it is possible to use these sensors underwater? If you waterproof them of course.