Build a Simple Robot (Kids)

 

Building a simple robot can be a fun and educational project.

Materials Needed:

1. Chassis: You can use a plastic container, a piece of wood, or any sturdy material.
2. Motors: Two DC motors for movement.
3. Wheels: Two wheels to attach to the motors.
4. Caster Wheel: One caster wheel for balance.
5. Motor Driver: L298N motor driver to control the motors.
6. Battery Pack: 4 AA batteries or a 7.4V Li-Po battery.
7. Arduino Uno: The brain of your robot.
8. Ultrasonic Sensor: HC-SR04 for obstacle detection.
9. Breadboard and Jumper Wires: For connecting components.
10. Miscellaneous: Screws, nuts, and adhesive.

Tools Needed:

• Screwdriver
• Soldering iron (optional)
• Hot glue gun (optional)
• Wire cutters

Steps:

1. Assemble the Chassis:

• Attach the DC motors to the chassis using screws or adhesive.
• Attach the wheels to the motors.
• Attach the caster wheel to the front or back of the chassis.

2. Wiring the Motors:

• Connect the motors to the L298N motor driver. Connect the left motor to the OUT1 and OUT2 pins and the right motor to the OUT3 and OUT4 pins.
• Connect the motor driver to the Arduino:
  • IN1 to Arduino pin 9
  • IN2 to Arduino pin 8
  • IN3 to Arduino pin 7
  • IN4 to Arduino pin 6
  • ENA to Arduino pin 10 (enable pin for the left motor)
  • ENB to Arduino pin 11 (enable pin for the right motor)
• Connect the motor driver's power input (12V and GND) to the battery pack.

3. Connect the Ultrasonic Sensor:

• Connect the VCC pin of the HC-SR04 to the 5V pin on the Arduino.
• Connect the GND pin to the GND pin on the Arduino.
• Connect the TRIG pin to Arduino pin 12.
• Connect the ECHO pin to Arduino pin 13.

4. Power the Arduino:

• Connect the Arduino to the battery pack using the VIN and GND pins.

5. Write the Code:

#include <AFMotor.h>

AF_DCMotor motor1(1);

AF_DCMotor motor2(2);

const int trigPin = 12;

const int echoPin = 13;

long duration;

int distance;

void setup() {

  Serial.begin(9600);

  pinMode(trigPin, OUTPUT);

  pinMode(echoPin, INPUT);

}

void loop() {

  digitalWrite(trigPin, LOW);

  delayMicroseconds(2);

  digitalWrite(trigPin, HIGH);

  delayMicroseconds(10);

  digitalWrite(trigPin, LOW);

  duration = pulseIn(echoPin, HIGH);

  distance = duration * 0.034 / 2;

  

  if (distance < 20) {

    motor1.setSpeed(0);

    motor2.setSpeed(0);

  } else {

    motor1.setSpeed(200);

    motor1.run(FORWARD);

    motor2.setSpeed(200);

    motor2.run(FORWARD);

  }

  

  delay(200);

}

• Upload the code to the Arduino using the Arduino IDE.

6. Test the Robot:

• Turn on the power and place your robot on the floor. It should move forward and stop when it detects an obstacle within 20 cm.

Tips:

• Ensure all connections are secure to prevent loose wiring.
• Adjust the speed and obstacle detection distance in the code as needed.
• Customize your robot by adding more sensors or functionalities.

Building a robot involves both hardware assembly and software programming, providing a comprehensive learning experience in robotics and electronics. Enjoy building your simple robot!