Introduction: DIY Obstacle Avoiding Robot

This time its a obstacle avoiding robot, which use a ultrasonic sensor , two motors , a motor driver and arduino unoto avoid objects. In this project a servo motor is shown but it is not used.It happens because I didn't find a ultrasonic bracket and I try to make one by my self it was successful but it was programmed to rotate and find the nearest area to go but it didn't rotate properly so I reprogrammed it not to rotate and if it detects a object it must go backwards and turn to right and continue the process. It is not a big problem and you can find a ultrasonic sensor bracket and fix it to the servo motor. I will put both codes, with servo and without servo. And lets make it!!!

Step 1: Things You Need +

Heres the things you needed to make this project.

  1. Arduino Uno Board + Cable.
  2. Ultrasonic Sensor HC-SR04.
  3. Ultrasonic Sensor bracket(I will tell you how to make but you can buy one if you can find).
  4. H-Bridge L298N Motor driver.
  5. Bovine wheel.
  6. Motors with Wheels.
  7. A plate or something like in the picture.
  8. 2 9v batteries.
  9. 2 9v batteries holders.
  10. A servo motor sg90.(Optional)
  11. A half breadboard.
  12. Jumper wires.
  13. Small cardboard (Optional).
  14. Cable ties.

Step 2: The Bracket (Optional)

Remember that this is optional and you can always buy a ultrasonic sensor bracket. First take a cardboard and fold it as shown and also fix it as shown and make a hole in the centre.Then fix the the bracket to the servo.

Step 3: Solder the Motors!

Now solder the motors and tape it.

Step 4: Mount All in Place!

Now mount the motors, arduino uno, H-Bridge L298N Motor Driver, Servo motor with Ultrasonic Sensor or only ultrasonic sensor(its optional) and the half breadboard.

Step 5: Connections +

Do all the connections as shown in the picture.

Step 6: Hot Glue and Cable Ties!

Now for the power supply I use a 2 9v batteries. In here we must think far and because of that I hot glue the holders on the motor.And there was a problem in this project. It was that the ultrasonic sensor was folded downwards and it was fixed by hot gluing a small piece of cardboard. Also for the cleanness of the robot I tie all the cables with cable ties.

Step 7: Programming.........

There are 2 types of coding for this robot one is with the servo and without servo. I have use without the servo. But don't worry because I will put both with the servo and without the servo codes. And for both codes you must download the newping library, which you can download from below URL.

https://bitbucket.org/teckel12/arduino-new-ping/do..

You must put the newping library to the libraries folder.

Now heres the code for with the servo.

#include <Servo.h> //Servo motor library. This is standard library
#include <NewPing.h> //Ultrasonic sensor function library. You must install this library

//our L298N control pins const int LeftMotorForward = 7; const int LeftMotorBackward = 6; const int RightMotorForward = 4; const int RightMotorBackward = 5;

//sensor pins #define trig_pin A1 //analog input 1 #define echo_pin A2 //analog input 2

#define maximum_distance 200 boolean goesForward = false; int distance = 100;

NewPing sonar(trig_pin, echo_pin, maximum_distance); //sensor function Servo servo_motor; //our servo name

void setup(){

pinMode(RightMotorForward, OUTPUT); pinMode(LeftMotorForward, OUTPUT); pinMode(LeftMotorBackward, OUTPUT); pinMode(RightMotorBackward, OUTPUT); servo_motor.attach(10); //our servo pin

servo_motor.write(115); delay(2000); distance = readPing(); delay(100); distance = readPing(); delay(100); distance = readPing(); delay(100); distance = readPing(); delay(100); }

void loop(){

int distanceRight = 0; int distanceLeft = 0; delay(50);

if (distance <= 20){ moveStop(); delay(300); moveBackward(); delay(400); moveStop(); delay(300); distanceRight = lookRight(); delay(300); distanceLeft = lookLeft(); delay(300);

if (distance >= distanceLeft){ turnRight(); moveStop(); } else{ turnLeft(); moveStop(); } } else{ moveForward(); } distance = readPing(); }

int lookRight(){ servo_motor.write(50); delay(500); int distance = readPing(); delay(100); servo_motor.write(115); return distance; }

int lookLeft(){ servo_motor.write(170); delay(500); int distance = readPing(); delay(100); servo_motor.write(115); return distance; delay(100); }

int readPing(){ delay(70); int cm = sonar.ping_cm(); if (cm==0){ cm=250; } return cm; }

void moveStop(){ digitalWrite(RightMotorForward, LOW); digitalWrite(LeftMotorForward, LOW); digitalWrite(RightMotorBackward, LOW); digitalWrite(LeftMotorBackward, LOW); }

void moveForward(){

if(!goesForward){

goesForward=true; digitalWrite(LeftMotorForward, HIGH); digitalWrite(RightMotorForward, HIGH); digitalWrite(LeftMotorBackward, LOW); digitalWrite(RightMotorBackward, LOW); } }

void moveBackward(){

goesForward=false;

digitalWrite(LeftMotorBackward, HIGH); digitalWrite(RightMotorBackward, HIGH); digitalWrite(LeftMotorForward, LOW); digitalWrite(RightMotorForward, LOW); }

void turnRight(){

digitalWrite(LeftMotorForward, HIGH); digitalWrite(RightMotorBackward, HIGH); digitalWrite(LeftMotorBackward, LOW); digitalWrite(RightMotorForward, LOW); delay(500); digitalWrite(LeftMotorForward, HIGH); digitalWrite(RightMotorForward, HIGH); digitalWrite(LeftMotorBackward, LOW); digitalWrite(RightMotorBackward, LOW); }

void turnLeft(){

digitalWrite(LeftMotorBackward, HIGH); digitalWrite(RightMotorForward, HIGH); digitalWrite(LeftMotorForward, LOW); digitalWrite(RightMotorBackward, LOW);

delay(500); digitalWrite(LeftMotorForward, HIGH); digitalWrite(RightMotorForward, HIGH); digitalWrite(LeftMotorBackward, LOW); digitalWrite(RightMotorBackward, LOW); }

And here's the code for without the servo.

#include <NewPing.h> //Ultrasonic sensor function library. You must install this library

//our L298N control pins const int LeftMotorForward = 7; const int LeftMotorBackward = 6; const int RightMotorForward = 5; const int RightMotorBackward = 4;

//sensor pins #define trig_pin A1 //analog input 1 #define echo_pin A2 //analog input 2

#define maximum_distance 200 boolean goesForward = false; int distance = 100;

NewPing sonar(trig_pin, echo_pin, maximum_distance); //sensor function

void setup(){

pinMode(RightMotorForward, OUTPUT); pinMode(LeftMotorForward, OUTPUT); pinMode(LeftMotorBackward, OUTPUT); pinMode(RightMotorBackward, OUTPUT); }

void loop(){

int distanceRight = 0; int distanceLeft = 0; delay(50);

if (distance <= 20){ moveStop(); delay(300); moveBackward(); delay(400); moveStop(); delay(300);

if (distance >= distanceLeft){ turnRight(); moveStop(); } else{ turnLeft(); moveStop(); } } else{ moveForward(); } distance = readPing(); }

int readPing(){ delay(70); int cm = sonar.ping_cm(); if (cm==0){ cm=250; } return cm; }

void moveStop(){ digitalWrite(RightMotorForward, LOW); digitalWrite(LeftMotorForward, LOW); digitalWrite(RightMotorBackward, LOW); digitalWrite(LeftMotorBackward, LOW); }

void moveForward(){

if(!goesForward){

goesForward=true; digitalWrite(LeftMotorForward, HIGH); digitalWrite(RightMotorForward, HIGH); digitalWrite(LeftMotorBackward, LOW); digitalWrite(RightMotorBackward, LOW); } }

void moveBackward(){

goesForward=false;

digitalWrite(LeftMotorBackward, HIGH); digitalWrite(RightMotorBackward, HIGH); digitalWrite(LeftMotorForward, LOW); digitalWrite(RightMotorForward, LOW); }

void turnRight(){

digitalWrite(LeftMotorForward, HIGH); digitalWrite(RightMotorBackward, HIGH); digitalWrite(LeftMotorBackward, LOW); digitalWrite(RightMotorForward, LOW); delay(500); digitalWrite(LeftMotorForward, HIGH); digitalWrite(RightMotorForward, HIGH); digitalWrite(LeftMotorBackward, LOW); digitalWrite(RightMotorBackward, LOW); }

void turnLeft(){

digitalWrite(LeftMotorBackward, HIGH); digitalWrite(RightMotorForward, HIGH); digitalWrite(LeftMotorForward, LOW); digitalWrite(RightMotorBackward, LOW);

delay(500); digitalWrite(LeftMotorForward, HIGH); digitalWrite(RightMotorForward, HIGH); digitalWrite(LeftMotorBackward, LOW); digitalWrite(RightMotorBackward, LOW); }

Step 8: Done!!!

And our project is done I wish you very good luck on making a Obstacle Avoiding Robot.

And don't forget to vote me!!?????????