14CORE Obstacle Avoidance Bot with HC-SR04, L293D Shield, SERVO & Arduino Microcontroller

This is the 14core design Obstacle Avoidance BOT with L293D Shield and HC-SR04 and Servo, which is capable of avoiding obstacles using an Ultrasonic Ranging Sensor. The HC-SR04 is economical sensor provides 2cm to 400cm of non-contact measurement functionality with a ranging accuracy that can reach up to 3mm. Each HC-SR04 module includes an ultrasonic transmitter, a receiver and a control circuit. There are only four pins that you need to worry about on the HC-SR04: VCC (Power), Trig (Trigger), Echo (Receive), and GND (Ground). If you’re new to H-BRIDGE / Motor controller just follow also this link L293D / L298N.

Components Required

Arduino Microcontroller
L298N / l293D UNO Shield
Smart Car Kit / Build your own Kit
HC-SR04 Ultrasonic Raging Sensor
2 or 4 Gearhead Motors
Servo
Jumper Wire / DuPont Wire (Optional)
Bread-board (Optional)

Wiring Diagram

Source Code

/*

14CORE OBSTACLE AVOINDACE ROBOT
======================TEST CODE 

*/

#include <NewPing.h> // 
#include <AFMotor.h> // You can download the code library below
#include <Servo.h> //

// Ultranic Pin Configuration

#define TRIG_PIN A5
#define ECHO_PIN A4

#define MAX_DISTANCE 400
#define MAX_SPEED 255
#define MAX_SPEED_OFFSET -8

#define COLL_DIST 20
#define TURN_DIST COLL_DIST+10
#define ACT_TIME 250

NewPing sonar(TRIG_PIN, ECHO_PIN, MAX_DISTANCE); 

AF_DCMotor motorR(1, MOTOR12_1KHZ); // Set motor #1, 1kHz PWM
AF_DCMotor motorL(4, MOTOR12_1KHZ); // Set motor #2, 1kHz PWM

Servo myservo;  // Set servo object to control a servo 
String motorSet = "";

int curDist = 0, pos, speedSet = 0;
//int pos;
//int speedSet = 0;

void setup() {
  
  myservo.attach(9);  // Set to attach the servo on pin 9 
  myservo.write(90);  // Write 90 to face servo forward
  delay(2000);

  motorSet = "FORWARD";
  moveForward();
  
}

void loop() {
  
  checkPath();
  
}

void checkPath() {
  
  int curLeft = 0; int curRight = 0; int curFront = 0;
  curDist = 0;
  
  checkForward();
  myservo.write(135);
  delay(100);
  for (pos = 135; pos >= 45; pos -= 45) {
    myservo.write(pos);
    delay(170);
    curDist = readPing();
    
    if (curDist < COLL_DIST) { checkCourse(); break; }
    if (curDist < TURN_DIST) { changePath(); } 
  
  }    
}  

int readPing() {
  int cm = 0;
  while (cm < 2) {int uS = sonar.ping(); cm = uS/US_ROUNDTRIP_CM;}
  return cm;
}

void checkForward() { 
  if (motorSet=="FORWARD") { motorR.run(FORWARD); motorL.run(FORWARD); } 
}    
void changePath() {

  if (pos < 90) { veerLeft(); } 
  if (pos > 90) { veerRight(); }
  
}

void veerRight() {
  motorR.run(BACKWARD);  motorL.run(FORWARD); 
  delay(ACT_TIME); 
  motorR.run(FORWARD);   motorL.run(FORWARD);
  motorSet = "FORWARD";
}

void veerLeft() {
  motorL.run(BACKWARD);  motorR.run(FORWARD); 
  delay(ACT_TIME); 
  motorL.run(FORWARD);   motorR.run(FORWARD);
  motorSet = "FORWARD";
}

void checkCourse() {
  moveBackward();
  delay(ACT_TIME);
  moveStop();
  setCourse();
}

void setCourse() {
  if (pos < 90) { turnRight(); } 
  if (pos > 90) { turnLeft(); }
}

void moveBackward() {
  motorSet = "BACKWARD";
  
  motorR.run(BACKWARD); // Turn right motor backward    
  motorL.run(BACKWARD);  // Turn left motor backward
  
  for (speedSet = 0; speedSet < MAX_SPEED; speedSet +=2)
  {
    motorL.setSpeed(speedSet);
    motorR.setSpeed(speedSet+MAX_SPEED_OFFSET);
    delay(5);
  }
}  

void moveForward() {
  motorSet = "FORWARD";
  checkForward();
  for (speedSet = 0; speedSet < MAX_SPEED; speedSet +=2)  {
    motorL.setSpeed(speedSet);
    motorR.setSpeed(speedSet+MAX_SPEED_OFFSET);
    delay(4);
  }
}

void moveStop() { motorR.run(RELEASE); motorL.run(RELEASE); }

void turnRight() {
  motorSet = "RIGHT";
  motorR.run(FORWARD);      // Turn right motor forward
  motorL.run(BACKWARD);     // Turn left motor backward
  delay(ACT_TIME);
  motorSet = "FORWARD";
  checkForward();
}  

void turnLeft() {
  motorSet = "LEFT";
  motorR.run(BACKWARD);     // Turn right motor backward
  motorL.run(FORWARD);      // Turn left motor forward
  delay(ACT_TIME);
  motorSet = "FORWARD";
  checkForward();
}

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14CORE OBSTACLE AVOINDACE ROBOT

======================TEST CODE

#include <NewPing.h> //

#include <AFMotor.h> // You can download the code library below

#include <Servo.h> //

// Ultranic Pin Configuration

#define TRIG_PIN A5

#define ECHO_PIN A4

#define MAX_DISTANCE 400

#define MAX_SPEED 255

#define MAX_SPEED_OFFSET -8

#define COLL_DIST 20

#define TURN_DIST COLL_DIST+10

#define ACT_TIME 250

NewPing sonar(TRIG_PIN, ECHO_PIN, MAX_DISTANCE);

AF_DCMotor motorR(1, MOTOR12_1KHZ); // Set motor #1, 1kHz PWM

AF_DCMotor motorL(4, MOTOR12_1KHZ); // Set motor #2, 1kHz PWM

Servo myservo; // Set servo object to control a servo

String motorSet = "";

int curDist = 0, pos, speedSet = 0;

//int pos;

//int speedSet = 0;

void setup() {

myservo.attach(9); // Set to attach the servo on pin 9

myservo.write(90); // Write 90 to face servo forward

delay(2000);

motorSet = "FORWARD";

moveForward();

}

void loop() {

checkPath();

}

void checkPath() {

int curLeft = 0; int curRight = 0; int curFront = 0;

curDist = 0;

checkForward();

myservo.write(135);

delay(100);

for (pos = 135; pos >= 45; pos -= 45) {

myservo.write(pos);

delay(170);

curDist = readPing();

if (curDist < COLL_DIST) { checkCourse(); break; }

if (curDist < TURN_DIST) { changePath(); }

}

int readPing() {

int cm = 0;

while (cm < 2) {int uS = sonar.ping(); cm = uS/US_ROUNDTRIP_CM;}

return cm;

}

void checkForward() {

if (motorSet=="FORWARD") { motorR.run(FORWARD); motorL.run(FORWARD); }

}

void changePath() {

if (pos < 90) { veerLeft(); }

if (pos > 90) { veerRight(); }

}

void veerRight() {

motorR.run(BACKWARD); motorL.run(FORWARD);

delay(ACT_TIME);

motorR.run(FORWARD); motorL.run(FORWARD);

motorSet = "FORWARD";

}

void veerLeft() {

motorL.run(BACKWARD); motorR.run(FORWARD);

delay(ACT_TIME);

motorL.run(FORWARD); motorR.run(FORWARD);

motorSet = "FORWARD";

}

void checkCourse() {

moveBackward();

delay(ACT_TIME);

moveStop();

setCourse();

}

void setCourse() {

if (pos < 90) { turnRight(); }

if (pos > 90) { turnLeft(); }

}

void moveBackward() {

motorSet = "BACKWARD";

motorR.run(BACKWARD); // Turn right motor backward

motorL.run(BACKWARD); // Turn left motor backward

for (speedSet = 0; speedSet < MAX_SPEED; speedSet +=2)

{

motorL.setSpeed(speedSet);

motorR.setSpeed(speedSet+MAX_SPEED_OFFSET);

delay(5);

}

void moveForward() {

motorSet = "FORWARD";

checkForward();

for (speedSet = 0; speedSet < MAX_SPEED; speedSet +=2) {

motorL.setSpeed(speedSet);

motorR.setSpeed(speedSet+MAX_SPEED_OFFSET);

delay(4);

}

void moveStop() { motorR.run(RELEASE); motorL.run(RELEASE); }

void turnRight() {

motorSet = "RIGHT";

motorR.run(FORWARD); // Turn right motor forward

motorL.run(BACKWARD); // Turn left motor backward

delay(ACT_TIME);

motorSet = "FORWARD";

checkForward();

}

void turnLeft() {

motorSet = "LEFT";

motorR.run(BACKWARD); // Turn right motor backward

motorL.run(FORWARD); // Turn left motor forward

delay(ACT_TIME);

motorSet = "FORWARD";

checkForward();

}

Downloads

Download the AFMotor Code Library Here | Zip
Download the NewPing Code Library Here | Zip

14CORE Obstacle Avoidance Bot with HC-SR04, L293D Shield, SERVO & Arduino Microcontroller

Tagged on: 14CORE Motors Robot Robotics Sensor

3 thoughts on “14CORE Obstacle Avoidance Bot with HC-SR04, L293D Shield, SERVO & Arduino Microcontroller”

elijah
at

Where do u connect the arduino?
- 14core EditorPost author
  at
  
  Note: it is actually an L2983D Arduino UNO Shield. see above image :) Regards
George Weah
at

Hi, can you send me a circuit and code for same but 2 servo’s and 2 ultrasonic sensor’s? Thanks

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3 thoughts on “14CORE Obstacle Avoidance Bot with HC-SR04, L293D Shield, SERVO & Arduino Microcontroller”

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