Simple obstacle avoiding robot using Arduino

Fun way to learn arduino

 Obstacle avoiding human

Obstacle avoiding Robot

Comparing Human to Robot

Connecting the Sensor

Reading Sensor

#include <NewPing.h>

#define PING_PIN  12
#define PING_MAX_DISTANCE 200
NewPing sonar(PING_PIN, PING_PIN, PING_MAX_DISTANCE);

void setup() {
  Serial.begin(9600);
}

void loop() { 
  delay(500);
  unsigned int distanceInCms = sonar.ping() / US_ROUNDTRIP_CM;
  Serial.println("Distance: " + String(distanceInCms) + "cm");
}

https://gist.github.com/endeepak/f816adad5867ee78551c#file-arduino-hc-sr04-ultrasonic-sensor-ino

Connecting the Motors

Operating Motors

int motor_left[] = {2, 3};
int motor_right[] = {7, 8};

void setup() {
  for(int i = 0; i < 2; i++){
    pinMode(motor_left[i], OUTPUT);
    pinMode(motor_right[i], OUTPUT);
  }
}

void loop() {
  delay(50);
  drive_forward();
}

void drive_forward() {
  digitalWrite(motor_left[0], HIGH); 
  digitalWrite(motor_left[1], LOW); 
  
  digitalWrite(motor_right[0], HIGH); 
  digitalWrite(motor_right[1], LOW); 
}

void drive_backward() {
  digitalWrite(motor_left[0], LOW); 
  digitalWrite(motor_left[1], HIGH); 
  
  digitalWrite(motor_right[0], LOW); 
  digitalWrite(motor_right[1], HIGH); 
}

void turn_left() {
  digitalWrite(motor_left[0], LOW); 
  digitalWrite(motor_left[1], HIGH); 
  
  digitalWrite(motor_right[0], HIGH); 
  digitalWrite(motor_right[1], LOW);
}

void turn_right() {
  digitalWrite(motor_left[0], HIGH); 
  digitalWrite(motor_left[1], LOW); 
  
  digitalWrite(motor_right[0], LOW); 
  digitalWrite(motor_right[1], HIGH); 
}

void motor_stop(){
  digitalWrite(motor_left[0], LOW); 
  digitalWrite(motor_left[1], LOW); 
  
  digitalWrite(motor_right[0], LOW); 
  digitalWrite(motor_right[1], LOW);
}

https://gist.github.com/endeepak/5b3395c1be5597397fdc#file-arduino-l293d-motor-driver-ino

The obstacle avoiding brain

// ..... Setup code omitted

void loop() { 
  delay(50);
  unsigned int distanceInCms = sonar.ping() / US_ROUNDTRIP_CM;
  if(distanceInCms != NO_ECHO && distanceInCms < MAX_DISTANCE_FROM_OBSTACLE_IN_CMS) {
    rotate_right(90);
  } else  {
    drive_forward();
  }
}

void rotate_right(int angleInDegrees) {
  for(int i=0; i< angleInDegrees; i++) {
    turn_right();
    delay(25);
  }
}

// .... Full code can be found in gist mentioned below

https://gist.github.com/endeepak/87c703fea2ad4e1eede2#file-arduino-obstacle-avoiding-robot-ino

Demo & Questions

Thank You

Links

• Instructions to build:  http://tech.endeepak.com/blog/2016/01/02/simple-obstacle-avoiding-robot-using-arduino/
• Other simple hardware projects : http://diyhacking.com