ESP32 Wi-Fi Controlled RC Car

April 12, 2025

Overview

In this tutorial, we will build an RC car that can be controlled via a Wi-Fi-based web interface using an ESP32. The car will have forward, backward, left, and right movement controls, along with a speed control slider.

Required Components

ESP32 Development Board
L298N Motor Driver
2 DC Motors
Battery Pack
Jumper Wires
Chassis with Wheels

Circuit Diagram

Diagram Representation:

Connect IN1 (L298N) to GPIO 27
Connect IN2 (L298N) to GPIO 26
Connect ENA (L298N) to GPIO 14
Connect IN3 (L298N) to GPIO 33
Connect IN4 (L298N) to GPIO 25
Connect ENB (L298N) to GPIO 32
Connect VCC (L298N) to 5V (ESP32 or External Power)
Connect GND (L298N) to GND (ESP32)

This setup allows the ESP32 to control the motors’ movement and speed via PWM signals.

Step 2: Upload the Code

Code Breakdown

Wi-Fi Setup: Connects to the given Wi-Fi network.
Web Server: Hosts a webpage for control buttons and a speed slider.
Motor Control: Controls the direction and speed of the motors.

Upload Code

Connect your ESP32 to the PC.
Select the correct COM Port in Tools → Port.
Upload the provided code.

#include <WiFi.h>
#include <WebServer.h>

// Replace with your network credentials
const char* ssid     = "Tesla";
const char* password = "elonDaddy";

// Create an instance of the WebServer on port 80
WebServer server(80);

// Motor 1
int motor1Pin1 = 27; 
int motor1Pin2 = 26; 
int enable1Pin = 14;

// Motor 2
int motor2Pin1 = 33; 
int motor2Pin2 = 25; 
int enable2Pin = 32;

// Setting PWM properties
const int freq = 30000;
const int resolution = 8;
int dutyCycle = 0;

String valueString = String(0);

void handleRoot() {
  const char html[] PROGMEM = R"rawliteral(
  <!DOCTYPE HTML><html>
  <head>
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <link rel="icon" href="data:,">
    <style>
      body {
        font-family: Arial, sans-serif;
        background: linear-gradient(135deg, #1e3c72, #2a5298);
        color: white;
        text-align: center;
        margin: 0;
        padding: 0;
      }
      h1 {
        margin-top: 20px;
        font-size: 28px;
        text-shadow: 2px 2px 5px rgba(0, 0, 0, 0.3);
      }
      .container {
        display: flex;
        flex-direction: column;
        align-items: center;
        justify-content: center;
        height: 80vh;
      }
      .button {
        background-color: #4CAF50;
        border: none;
        color: white;
        padding: 14px 32px;
        font-size: 24px;
        margin: 10px;
        border-radius: 10px;
        cursor: pointer;
        transition: 0.3s;
        box-shadow: 3px 3px 8px rgba(0, 0, 0, 0.3);
      }
      .button:hover { background-color: #45a049; }
      .button2 { background-color: #d9534f; }
      .button2:hover { background-color: #c9302c; }
      .direction-buttons {
        display: flex;
        justify-content: center;
        gap: 15px;
        margin-top: 10px;
      }
      .slider-container {
        margin-top: 20px;
      }
      input[type="range"] {
        width: 80%;
        height: 10px;
        background: #ddd;
        border-radius: 5px;
        outline: none;
        -webkit-appearance: none;
      }
      input[type="range"]::-webkit-slider-thumb {
        -webkit-appearance: none;
        appearance: none;
        width: 25px;
        height: 25px;
        background: #4CAF50;
        border-radius: 50%;
        cursor: pointer;
      }
    </style>
    <script>
      function moveForward() { fetch('/forward'); }
      function moveLeft() { fetch('/left'); }
      function stopRobot() { fetch('/stop'); }
      function moveRight() { fetch('/right'); }
      function moveReverse() { fetch('/reverse'); }

      function updateMotorSpeed(pos) {
        document.getElementById('motorSpeed').innerText = pos;
        fetch(`/speed?value=${pos}`);
      }
    </script>
  </head>
  <body>
    <div class="container">
      <h1>ESP32 Motor Control</h1>
      <button class="button" onclick="moveForward()">FORWARD</button>
      <div class="direction-buttons">
        <button class="button" onclick="moveLeft()">LEFT</button>
        <button class="button button2" onclick="stopRobot()">STOP</button>
        <button class="button" onclick="moveRight()">RIGHT</button>
      </div>
      <button class="button" onclick="moveReverse()">REVERSE</button>
      
      <div class="slider-container">
        <p>Motor Speed: <span id="motorSpeed">0</span></p>
        <input type="range" min="0" max="100" step="25" id="motorSlider" oninput="updateMotorSpeed(this.value)" value="0"/>
      </div>
    </div>
  </body>
  </html>)rawliteral";
  server.send(200, "text/html", html);
}

void handleForward() {
  Serial.println("Forward");
  digitalWrite(motor1Pin1, LOW);
  digitalWrite(motor1Pin2, HIGH); 
  digitalWrite(motor2Pin1, LOW);
  digitalWrite(motor2Pin2, HIGH);
  server.send(200);
}

void handleLeft() {
  Serial.println("Left");
  digitalWrite(motor1Pin1, LOW); 
  digitalWrite(motor1Pin2, LOW); 
  digitalWrite(motor2Pin1, LOW);
  digitalWrite(motor2Pin2, HIGH);
  server.send(200);
}

void handleStop() {
  Serial.println("Stop");
  digitalWrite(motor1Pin1, LOW); 
  digitalWrite(motor1Pin2, LOW); 
  digitalWrite(motor2Pin1, LOW);
  digitalWrite(motor2Pin2, LOW);   
  server.send(200);
}

void handleRight() {
  Serial.println("Right");
  digitalWrite(motor1Pin1, LOW); 
  digitalWrite(motor1Pin2, HIGH); 
  digitalWrite(motor2Pin1, LOW);
  digitalWrite(motor2Pin2, LOW);    
  server.send(200);
}

void handleReverse() {
  Serial.println("Reverse");
  digitalWrite(motor1Pin1, HIGH);
  digitalWrite(motor1Pin2, LOW); 
  digitalWrite(motor2Pin1, HIGH);
  digitalWrite(motor2Pin2, LOW);          
  server.send(200);
}

void handleSpeed() {
  if (server.hasArg("value")) {
    valueString = server.arg("value");
    int value = valueString.toInt();
    if (value == 0) {
      ledcWrite(enable1Pin, 0);
      ledcWrite(enable2Pin, 0);
      digitalWrite(motor1Pin1, LOW); 
      digitalWrite(motor1Pin2, LOW); 
      digitalWrite(motor2Pin1, LOW);
      digitalWrite(motor2Pin2, LOW);   
    } else { 
      dutyCycle = map(value, 25, 100, 200, 255);
      ledcWrite(enable1Pin, dutyCycle);
      ledcWrite(enable2Pin, dutyCycle);
      Serial.println("Motor speed set to " + String(value));
    }
  }
  server.send(200);
}

void setup() {
  Serial.begin(115200);

  // Set the Motor pins as outputs
  pinMode(motor1Pin1, OUTPUT);
  pinMode(motor1Pin2, OUTPUT);
  pinMode(motor2Pin1, OUTPUT);
  pinMode(motor2Pin2, OUTPUT);

  // Configure PWM Pins
  ledcAttach(enable1Pin, freq, resolution);
  ledcAttach(enable2Pin, freq, resolution);
    
  // Initialize PWM with 0 duty cycle
  ledcWrite(enable1Pin, 0);
  ledcWrite(enable2Pin, 0);
  
  // Connect to Wi-Fi
  Serial.print("Connecting to ");
  Serial.println(ssid);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.println("WiFi connected.");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());

  // Define routes
  server.on("/", handleRoot);
  server.on("/forward", handleForward);
  server.on("/left", handleLeft);
  server.on("/stop", handleStop);
  server.on("/right", handleRight);
  server.on("/reverse", handleReverse);
  server.on("/speed", handleSpeed);

  // Start the server
  server.begin();
}

void loop() {
  server.handleClient();
}

Step 3: Access the Web Interface

Open Serial Monitor (Baud rate: 115200).
Look for the ESP32’s IP Address (e.g., 192.168.1.100).
Open a web browser and enter ESP32’s IP Address.
You should see a webpage with control buttons.

Step 4: Control the Car

Buttons

FORWARD: Moves the car forward.
LEFT: Turns the car left.
STOP: Stops the motors.
RIGHT: Turns the car right.
REVERSE: Moves the car backward.

Speed Control

Use the slider to adjust motor speed (0% to 100%).

Troubleshooting

Not Connecting to Wi-Fi?
Check SSID and Password.
Ensure your router is in range.

Motors Not Moving?

Check motor driver connections.
Ensure your power supply is sufficient.

ESP32 Not Responding?

Press the BOOT button while uploading code.

Conclusion

You have successfully built a Wi-Fi-controlled RC car using ESP32! 🚗💨

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