The Complete Guide to Basic Robotics: Sensors, Motors, Microcontrollers, and Arduino Programming

 Basic Robotics

1. Introduction

Robotics is an interdisciplinary field that combines mechanical engineering, electronics, and computer science to design, build, and program robots. In the modern era, robots have been used in various sectors such as industry, agriculture, medicine, the military, and even households.

Basic robotics studies the foundations of robotic systems, from physical components such as sensors and actuators, to programming logic and algorithms that enable robots to operate autonomously or semi-automatically.

2. Robot Components: Sensors, Motors, and Microcontrollers

To build a robot, we must understand three main components:

2.1 Sensors

Sensors are the part of a robot that receives information from its environment. Without sensors, the robot would not be able to respond to the outside world.

Types of sensors:

Distance Sensors (Ultrasonic, Infrared, LIDAR):

• Used to detect objects around the robot.
• Ultrasonic sensors such as the HC-SR04 measure distance based on the reflection of sound waves.
• Infrared is often used for line or edge detection.

Color and Light Sensors:

• Used in line follower robots to follow a specific colored line.
• Examples: TCS3200, LDR.

Temperature and Humidity Sensors:

• Useful for robotic applications in agriculture or smart spaces.
• Examples: DHT11, DHT22.

Motion and Position Sensors (IMU):

• Inertial Measurement Units (IMUs) such as the MPU6050 are used to detect orientation, rotation, and acceleration.

Touch and Pressure Sensors:

• To detect whether the robot is touching another object or experiencing a collision.

2.2 Motors (Actuators)

Motors function as the "muscles" of a robot, producing movement. Motors convert electrical energy into mechanical energy.

Motor Types:

DC Motors:

• Used to drive wheels or other mechanical parts.
• Easy to control and widely available.

Servo Motors:

• Provide precise positional control.
• Often used in humanoid robots or robotic arms.

Stepper Motors:

• Move in small, precise steps.
• Suitable for positional control, such as in 3D printers or CNC machines.

2.3 Microcontroller

A microcontroller is the brain of a robot, managing the interaction between sensors and actuators. It is the part that executes the robot's program or logic.

Examples of Microcontrollers:

Arduino (UNO, Nano, Mega):

• Very popular among beginners.
• Easy to use and has extensive documentation.

Raspberry Pi:

• More like a mini computer.
• Can run an operating system and is better suited for complex tasks.

ESP8266 / ESP32:

• Microcontrollers with built-in Wi-Fi/Bluetooth.
• Suitable for IoT-based robots.

3. Introduction to Robot Programming with Arduino or ROS

3.1 Arduino: A Popular Programming Platform

Arduino is an open-source platform consisting of a microcontroller circuit board and a development environment (IDE) for programming. Arduino programming uses a simplified version of the C/C++ language.

Basic Arduino Programming Structure:

 void setup() {

  // kode inisialisasi, dijalankan sekali

  pinMode(13, OUTPUT);

}

void loop() {

  // kode utama, dijalankan berulang

  digitalWrite(13, HIGH);

  delay(1000);

  digitalWrite(13, LOW);

  delay(1000);

}

In robots, Arduino is used to:

• Read input from sensors
• Control motors and LEDs
• Implement obstacle avoidance logic
• Send and receive data via serial communication

3.2 ROS (Robot Operating System)

ROS is an open-source framework for developing complex robotics software, typically used in advanced robotic systems.

Key Features of ROS:

• Modular and Distributed: Robot components can be developed as communicating nodes.
• Extensive Library: Numerous packages for navigation, image processing, SLAM, and more are available.
• Gazebo Simulation: ROS integrates with simulators like Gazebo for virtual testing.

A simple example of ROS architecture:

• Node A reads data from a proximity sensor.
• Node B controls a motor based on data from Node A.
• Communication between nodes uses a publish-subscribe protocol.

4. Navigation and Obstacle Avoidance Algorithms

Navigation and obstacle avoidance are at the heart of mobile robotics. Robots must be able to move from one point to another while avoiding objects in their path.

4.1 Basic Navigation

Line Following Algorithm

• Uses IR sensors to detect black lines on a white surface.
• If the left sensor detects a line, the robot turns left, and vice versa.

if (Left sensor == BLACK && Right sensor == WHITE) {

turnLeft();

} else if (Left sensor == WHITE && Right sensor == BLACK) {

turnRight();

} else {

forward();

}

4.2 Obstacle Avoidance

1. Ultrasonic Sensor Threshold Method

If the distance to an object is less than a certain threshold, the robot will change direction.

long distance = readUltrasonicSensor();

if (distance < 20) {

back();

delay(500);

turnRight();

} else {

forward();

}

2. Bug/Wall Following Algorithm

The robot follows a wall or obstacle until it finds a clear path.

3. A* (A-Star) Algorithm for Mapping and Navigation

• Suitable for robots with a mapping system (SLAM).
• The robot calculates the shortest path from the current position to the destination.

5. Examples of Simple Robot Projects

Here are some projects you can try as an introduction:

5.1 Line Follower Robot

Components:

• 2 DC motors
• IR Array Sensor (3 or 5 sensors)
• Arduino UNO
• L298N motor driver
• Robot frame and wheels

Logic:

• The sensors read the black line.
• The robot moves along the line using simple if-else logic.

5.2 Obstacle Avoidance Robot

Components:

• HC-SR04 Ultrasonic Sensor
• DC motor and motor driver
• Arduino UNO
• Battery and robot frame

Steps:

• Read the distance from the sensor.
• If it is too close to an object, the robot backs away and turns.
• If there are no obstacles, the robot moves forward.

5.3 Simple Robotic Arm

Components:

• 4-6 servo motors
• Arduino Uno
• Potentiometer (for manual control) or joystick

Application:

• The robot arm can be used to pick up and move objects.
• 5.4 Remote Control Robot (Bluetooth Control Robot)

Components:

• HC-05 Bluetooth Module
• DC Motor
• Arduino Uno
• Android Application (such as Bluetooth RC Controller)

Function:

• The robot is controlled via smartphone via Bluetooth commands.
• 5.5 IoT Robot Monitoring (ESP32 + Sensors)

Components:

• ESP32
• Temperature and humidity sensor (DHT11)
• IoT Platform such as Blynk or Thingspeak

Function:

• The robot sends sensor data to the internet and can be monitored in real time.

6. Conclusion

Basic robotics provides an essential foundation for developing robotic systems. By understanding components such as sensors, motors, and microcontrollers, as well as programming logic using Arduino or ROS, we can build a wide variety of robotic projects, from simple to complex.

Learning robotics isn't just about assembling hardware; it's also about integrating sensors, actuators, and logical algorithms so that robots can perform specific tasks autonomously. The more complex a robotic system, the more important the role of programming and integration between systems.

Simple projects like line follower and obstacle avoider robots are an excellent first step in understanding these basic concepts. With further exploration, development towards more intelligent and autonomous robots, such as SLAM or AI-based navigation robots, is possible.