Arduino

How to build an autonomous car with Arduino

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By Jackson Taylor

Building an autonomous car with Arduino is a rewarding and challenging project that brings together robotics, electronics, and programming. Whether you’re a hobbyist or a beginner in the world of electronics, Arduino offers an excellent platform to get started. In this guide, we’ll take you through the essential components, steps, and tips to help you build your own autonomous car from scratch.

Understanding the Basics of an Autonomous Car

Before diving into the building process, it’s important to understand what makes an autonomous car function. Autonomous cars, often referred to as self-driving cars, use sensors, cameras, and algorithms to navigate and make decisions without human intervention. For an Arduino-based autonomous car, we’ll leverage simple sensors, motors, and the Arduino board to replicate the basic functionality of an autonomous vehicle.

Key Components for Your Autonomous Car

To get started, you’ll need several key components that will allow your Arduino car to function properly. Here’s a list of the basic components required:
  • Arduino Board (Uno or Nano): The brain of the project.
  • DC Motors: For movement and control.
  • Motor Driver: To control the direction and speed of the motors.
  • Ultrasonic Sensor: For obstacle detection and collision avoidance.
  • Servo Motor: To control steering.
  • Chassis: The frame of the car.
  • Power Supply: Batteries to power the Arduino and motors.
  • Wires and Breadboard: For connecting the components.

Preparing the Arduino Board and Motors

The Arduino board serves as the central controller of your autonomous car, interpreting sensor data and controlling the motors accordingly. Begin by setting up the Arduino board and connecting it to your computer. You’ll need to upload the appropriate code that allows the board to read sensor inputs and control the motors.

Choosing the Right Motors for Your Car

DC motors are commonly used in DIY robotics projects for their simplicity and affordability. You’ll use two motors to control the movement of your autonomous car, one for each wheel. The motors should be connected to the motor driver, which will manage the speed and direction of the motors based on the commands from the Arduino.
See also
Arduino self-driving car using GPS

Building the Chassis for Your Autonomous Car

The chassis is the physical structure of your car, where all the components will be mounted. You can purchase pre-made chassis kits online, or you can build one using materials like plastic or cardboard. Ensure that the chassis is sturdy and has enough space to fit the Arduino board, motors, sensors, and power supply.

Mounting the Motors and Wheels

Attach the DC motors to the chassis using screws or mounting brackets. Ensure that the wheels are securely attached to the motors, and that they can spin freely. Position the motors in a way that allows the car to move forward, backward, and turn easily.

Wiring the Components Together

Now it’s time to wire the components to the Arduino board. Follow these steps:
  1. Motor Driver: Connect the motor driver to the Arduino board, making sure the pins for motor control are properly aligned.
  2. Motors: Connect the two DC motors to the motor driver, ensuring the correct polarity.
  3. Ultrasonic Sensor: Wire the ultrasonic sensor to the Arduino board, ensuring that the trigger and echo pins are connected to the right ports.
  4. Servo Motor: Connect the servo motor to the Arduino board for steering control.
  5. Power Supply: Finally, ensure the power supply is connected to both the Arduino and the motors.

Programming the Arduino

With the hardware in place, the next step is programming the Arduino to control your autonomous car. You’ll write a program that processes data from the ultrasonic sensor and controls the motors accordingly. The basic functionality you need includes:
  • Obstacle Detection: The ultrasonic sensor sends a signal to measure the distance to objects. If an obstacle is detected, the car should stop or change direction.
  • Movement Control: The motors should drive the car forward, backward, and turn left or right, depending on sensor inputs.
  • Steering: Use the servo motor to adjust the steering of the car to help it navigate around obstacles.
See also
Arduino self-driving car using computer vision
Here’s a simple code structure for obstacle detection and movement control:
cpp
#include <Servo.h> Servo steering; // Servo motor for steering int trigPin = 9; // Trigger pin for ultrasonic sensor int echoPin = 10; // Echo pin for ultrasonic sensor int motor1Pin = 6; // Motor 1 control pin int motor2Pin = 5; // Motor 2 control pin void setup() { steering.attach(11); // Attach servo motor to pin 11 pinMode(trigPin, OUTPUT); pinMode(echoPin, INPUT); pinMode(motor1Pin, OUTPUT); pinMode(motor2Pin, OUTPUT); } void loop() { long duration, distance; // Send pulse to trigger pin digitalWrite(trigPin, LOW); delayMicroseconds(2); digitalWrite(trigPin, HIGH); delayMicroseconds(10); digitalWrite(trigPin, LOW); // Read the duration of the pulse from the echo pin duration = pulseIn(echoPin, HIGH); distance = (duration / 2) / 29.1; // Check if the car is near an obstacle if (distance < 20) { // Stop the car if an obstacle is detected stopCar(); } else { // Move the car forward if no obstacle is detected moveForward(); } } void moveForward() { digitalWrite(motor1Pin, HIGH); digitalWrite(motor2Pin, HIGH); steering.write(90); // Adjust the steering } void stopCar() { digitalWrite(motor1Pin, LOW); digitalWrite(motor2Pin, LOW); }

Testing and Calibration

After uploading the code to the Arduino board, it’s time to test your autonomous car. Place the car on a flat surface and test it by moving obstacles in its path. Ensure that the ultrasonic sensor detects the obstacles correctly and that the car changes direction or stops when necessary. If the car is not responding as expected, check the wiring and ensure that all sensors are functioning correctly. You may need to adjust the code to fine-tune the movement control and obstacle avoidance.

Advanced Features for Your Autonomous Car

Once your basic car is working, you can add more advanced features to make it smarter:
  • Line Following: Use infrared sensors to detect and follow a line on the ground, making the car follow a predefined path.
  • Bluetooth Control: Add a Bluetooth module to control the car remotely via a smartphone or tablet.
  • Camera Integration: Integrate a camera module to add computer vision for more advanced navigation.
See also
Arduino data logging to cloud storage

Final Thoughts

Building an autonomous car with Arduino is a fun and educational project that combines hardware, software, and problem-solving skills. As you progress, you can enhance the capabilities of your car with more sensors, advanced algorithms, and even remote control features. With patience and practice, you can create a fully autonomous vehicle powered by Arduino. Happy building!

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