Ultimate Beginner’s Guide to Making a WiFi-Controlled Car

Introduction

If you're new to electronics and IoT, this project is a perfect way to start! In this tutorial, we will create a WiFi-controlled car using the ESP8266 NodeMCU. This car can be controlled from a mobile application over WiFi, making it an excellent learning experience for beginners in embedded systems and robotics.

Project Overview

The WiFi-controlled car is a simple robotic vehicle that uses a microcontroller (ESP8266) to communicate with a motor driver (L298N) and control the movement of two DC motors. The car receives commands via WiFi from a mobile application, enabling it to move forward, backward, turn left, and turn right.

Components Required

1. ESP8266 NodeMCU – The microcontroller that enables WiFi connectivity.

2. L298N Motor Driver Module – Controls the speed and direction of DC motors.

3. 2 x 3.6V DC Motors – Drive the car’s wheels.

4. 2 Rear Wheels & 1 Omni-Directional Front Wheel – Provides movement and stability.

5. 12V Battery – Powers the motor driver and motors.

6. Smartphone Application – To control the car via WiFi.

Circuit Schematic and Connections

The L298N motor driver is connected to the two motors while a 12V power supply drives the motor driver.

Understanding the Car’s Functionality

• ESP8266 Hosts a Web Server: The microcontroller runs a small web server to handle movement commands.

• Smartphone App Sends Commands: The app sends signals via WiFi to control direction and speed.

• L298N Motor Driver Activates Motors: Based on the received command, the motors move forward, backward, left, or right.

• Real-time Control: The car moves instantly as per the app’s input.

How to Design the Mobile App (APK)

To control the car, we will design a basic mobile application using MIT App Inventor.

Steps to Create the App:

1. Open MIT App Inventor (Click here).

2. Create a New Project and name it "WiFi_Car_Controller".

3. Add Components:

   • Buttons for movement (Forward, Backward, Left, Right, Stop).

   • Web Component to send commands to ESP8266.

4. Configure Web Component:

   • Set URL to ESP8266's IP address.

   • Set Request Method to GET.

5. Assign Button Actions:

   • Forward → Send "?State=F".

   • Backward → Send "?State=B".

   • Left → Send "?State=L".

   • Right → Send "?State=R".

   • Stop → Send "?State=S".

6. Build the APK and install it on your smartphone.

Working Demonstration

GitHub Repository

Access the complete source code, circuit diagram, and mobile app files here:

Further Improvements

Here are some ways to enhance this project:

• Add a Camera: Use an ESP32-CAM for live video streaming.

• Voice Control: Integrate voice commands using Google Assistant.

• Obstacle Avoidance: Use an ultrasonic sensor to detect obstacles.

• Speed Control: Implement PWM-based motor speed adjustments.

• Battery Level Indicator: Display battery percentage on the mobile app.

Resources and References

1. MIT App Inventor Guide - [MIT App Inventor]

2. L298N Motor Driver Datasheet - [L298N Datasheet]

3. YouTube Tutorial - [View on YouTube]

Have fun building!