Build Your Own Mobile Robot

What is a Robot?

A robot is a machine programmable by a computer that can carry out difficult tasks automatically. Robots are of different types. The earliest robots were crane-like structures used to do assembly line operations in factories. They were used to perform dull, dirty and dangerous (3D) tasks in place of human workers. The word “robot” comes from the Czech word “robota” meaning “forced labour”.

In recent years, mobile robots have become popular, such as R2D2, CBPO and BB-f robots in Star Wars movie. Robots can move using wheels (like cars), tracks (like tanks), legs (like humans), move in air or over water (like drones), go underwater and so on. The latest trend in robotics is to build humanoid robots like Honda’s Asimo.



What is an Arduino?

Understanding about Arduino requires prior knowledge about a microcontroller. A microcontroller is a computer present in a single small chip called as the integrated circuit. It is dedicated to perform one task and execute one specific application. It contains memory, programmable input/output peripherals as well a processor.

An Arduino is nothing but a microcontroller board which can perform any task as per your instructions. You give your instructions in the form of few lines of codes. Based on that, it can automatically turn ON/OFF a light, control motors and so on. Arduino can interact with buttons, LEDs, motors, speakers, GPS units, cameras, the internet, and even your smart-phone or your TV! This flexibility combined with the fact that the Arduino software is free, the hardware boards are pretty cheap, and both the software and hardware are easy to learn are the reasons that this tiny board has become so popular.

Wouldn’t you want to work with such a masterpiece?

Let’s get started.


Components Required


SI.NO Name of the component Component Use
1 Arduino Uno microcontroller


This is the control unit of our mobile robot
2 12V Adapter


This is used to power our control unit
3 L293D Motor Driver This is used to amplify the signals from the controller in order to run the motor
4 12V Lead-Acid Rechargeable


This is our voltage source
5 HC-05 Bluetooth module This is used to communicate with our mobile robot over a short distance
6 KA7805 Voltage Regulator This is used to regulate the power sent to the Arduino to 5V
7 Connecting wires These are the wires used to connect the different electronic components
8 Screw driver This is the tool used to fasten the wires tightly to the components
9 Wire stripper This tool is used to strip off the wires for connection
10 Plastic box casing This is a box made of plastic used as the encasing for our robot
11 Digital

Multi meter

This meter is used to check the connectivity as well as find the voltage between any two points
12 RC servo This is used for the rotation of the dome-shaped head of our robot
13 Castor wheel


This is used to give easy rolling for our robot
14 Acrylic sheet These are the sheets upon which the components would be mounted
15 DC Toy motor

(Quantity: 2)

This is the DC motor used to drive our robot
16 Wheels

(Quantity: 2)

This is used for easier dragging of the load of the robot
17 Bot chassis This is the underpart of the robot upon which all the components are mounted


How Much Does It Cost?

SI.NO Name of the component Total cost (INR)
1. Bot Chassis 120
2. Arduino Uno 500
3 Lead-Acid Battery 480
4 L293D driver 150
5 Body plastic 300
6 Wheels 50
7 DC toy motor 200
8 Bluetooth module 140
9 Wires 50
10 RC Servo 150
11 Fasteners 100
12 Acrylic sheets 120
13 Castor wheel 20
Total cost 2,380



How to Build Your Own Robot?

  1. Attach the two motors to the chassis and machine the acrylic sheets to circular shapes according to the requirement
  1. The pin out of the L293D motor driver is shown in fig.2.
  1. Make the connections as per given in the figure fig.1.
  1. Connect the Bluetooth to the Arduino Uno as per given in the figure fig.3.
  1. Connect the Vcc and Gnd of the Bluetooth module to 5V and GND of Arduino Uno
  1. Connect the Tx and Rx pin of the Bluetooth module to Rx (digital pin 0) and Tx (digital pin 1) pins of the Arduino Uno respectively
  2. The motor driver has two enable pins. These enable pins act as a switch to control the two DC motors. Connect them to the digital pins 6 and 5 of the Arduino Uno
  3. Connect the motor inputs In1, In2, In3 and In4 to the digital pins 2, 3, 4 and 7 of the Arduino Uno
  4. Connect the motor outputs Out1, Out2, Out3 and Out4 to the positive and negative terminals of the DC toy motor
  5. Connect the power supply to the power supply of the motor driver
  6. Connect the RC Servo to Arduino as per given in the figure Fig.4.
  7. The control signal is given to the digital pin 9 of the Arduino



Stages of Assembling the Mobile Robot

  1. Motors attached to the Chassis of the robot
  2. Components mounted onto the structure
  3. The completed robot!



Robots are very appealing to playful learning by school children. Interactive learning cannot be completely achieved by the chalk and talk technique. Hence, such initiatives of using robots for teaching and learning are sure to intrigue the minds of students and aid them in developing innovations and technologies.

The Teaching-learning centre takes pride in conducting such events for the school children and we would also like to thank our institution and the schools for extending their support and exhibiting great enthusiasm.

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