Circuit Documentation

Summary

The circuit in question is designed to control multiple DC motors and servos using an ESP32 microcontroller. The ESP32 is responsible for driving a pair of L298N DC motor drivers, which in turn control the speed and direction of four DC motors. Additionally, the ESP32 manages the position of four servos. The circuit also includes two HC-SR04 ultrasonic sensors for distance measurement. Power management is handled by a 12V battery, a 12V to 5V step-down power converter, and a 48V to 5V converter to ensure that all components receive the correct operating voltage. The ESP32 is also equipped with Wi-Fi capabilities, allowing for remote control via a web server.

Component List

Microcontroller

• ESP32 (30 pin): A Wi-Fi and Bluetooth enabled microcontroller that is the central controller of the circuit.

Motor Drivers

• L298N DC motor driver: Used to control the direction and speed of DC motors.

Motors

• DC Motor: Four individual motors controlled by the L298N motor drivers.

Servos

• Servo: Four servos controlled by the ESP32 for precise angular movement.

Sensors

• HC-SR04 Ultrasonic Sensor: Two sensors used for distance measurement.

Power Management

• 12v to 5v Step Down Power Converter: Converts 12V to 5V to power the servos and the ESP32.
• 48v to 5v Converter: Steps down 48V to 5V, likely used for sensor power supply.
• Battery 12v: Provides the main power source for the circuit.

Miscellaneous

• Comment: Placeholder components that may represent annotations or notes in the circuit design.

Wiring Details

ESP32 (30 pin)

• D32, D33 connected to L298N motor driver (control signals for motor driver)
• D26, D27, D14, D12, D13, D15 connected to another L298N motor driver (control signals for motor driver)
• D23, D22, D21, D19 connected to HC-SR04 ultrasonic sensors (trigger and echo signals)
• D18, D5, D4, D2 connected to servos (control pulses)
• Vin connected to 12V power supply
• GND connected to common ground

L298N DC motor driver

• IN1, IN2, IN3, IN4 connected to ESP32 (control signals from microcontroller)
• OUT1, OUT2, OUT3, OUT4 connected to DC motors (output to motors)
• 12V connected to 12V power supply
• GND connected to common ground

DC Motor

• pin 1, pin 2 connected to L298N motor driver (motor terminals)

Servo

• gnd connected to common ground
• vcc connected to 5V power supply
• pulse connected to ESP32 (control signal from microcontroller)

HC-SR04 Ultrasonic Sensor

• VCC connected to 5V power supply
• TRIG, ECHO connected to ESP32 (trigger and echo signals)
• GND connected to common ground

12v to 5v Step Down Power Converter

• VIN 9v-36v, VIN+ connected to 12V power supply
• USB OUTPUT 5V, 5v OUTPUT connected to servos and ESP32 (5V power output)
• GND connected to common ground

Battery 12v

• + connected to 12V power supply line
• - connected to common ground

48v to 5v Converter

• out+, out-- connected to HC-SR04 ultrasonic sensors (5V power output)
• in+, in-- connected to 48V power supply line

Documented Code

#include <WiFi.h>
#include <ESPAsyncWebServer.h>
#include <Servo.h>

// Motor pins (L298N Motor Driver)
const int motor1Pin1 = 26;
const int motor1Pin2 = 27;
const int motor2Pin1 = 14;
const int motor2Pin2 = 12;
const int motor3Pin1 = 13;
const int motor3Pin2 = 15;
const int motor4Pin1 = 32;
const int motor4Pin2 = 33;

// Servo pins
Servo servo1;
Servo servo2;
Servo servo3;
Servo servo4;

const int servo1Pin = 2;
const int servo2Pin = 4;
const int servo3Pin = 5;
const int servo4Pin = 18;

// Wi-Fi credentials
const char *ssid = "YOUR_SSID";
const char *password = "YOUR_PASSWORD";

// Server object
AsyncWebServer server(80);

// Function to stop all motors
void stopMotors() {
  digitalWrite(motor1Pin1, LOW);
  digitalWrite(motor1Pin2, LOW);
  digitalWrite(motor2Pin1, LOW);
  digitalWrite(motor2Pin2, LOW);
  digitalWrite(motor3Pin1, LOW);
  digitalWrite(motor3Pin2, LOW);
  digitalWrite(motor4Pin1, LOW);
  digitalWrite(motor4Pin2, LOW);
}

void setup() {
  // Initialize Serial Monitor
  Serial.begin(115200);

  // Setup motor pins
  pinMode(motor1Pin1, OUTPUT);
  pinMode(motor1Pin2, OUTPUT);
  pinMode(motor2Pin1, OUTPUT);
  pinMode(motor2Pin2, OUTPUT);
  pinMode(motor3Pin1, OUTPUT);
  pinMode(motor3Pin2, OUTPUT);
  pinMode(motor4Pin1, OUTPUT);
  pinMode(motor4Pin2, OUTPUT);

  // Attach servos
  servo1.attach(servo1Pin);
  servo2.attach(servo2Pin);
  servo3.attach(servo3Pin);
  servo4.attach(servo4Pin);

  // Connect to Wi-Fi
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Connecting to WiFi...");
  }
  Serial.println("Connected to WiFi");

  // Setup web server routes
  server.on("/", HTTP_GET, [](AsyncWebServerRequest *request) {
    request->send(200, "text/plain", "Control your RC Car");
  });

  // Control routes (adjust as per app logic)
  server.on("/forward", HTTP_GET, [](AsyncWebServerRequest *request) {
    digitalWrite(motor1Pin1, HIGH);
    digitalWrite(motor1Pin2, LOW);
    digitalWrite(motor2Pin1, HIGH);
    digitalWrite(motor2Pin2, LOW);
    digitalWrite(motor3Pin1, HIGH);
    digitalWrite(motor3Pin2, LOW);
    digitalWrite(motor4Pin1, HIGH);
    digitalWrite(motor4Pin2, LOW);
    request->send(200, "text/plain", "Moving Forward");
  });

  server.on("/stop", HTTP_GET, [](AsyncWebServerRequest *request) {
    stopMotors();
    request->send(200, "text/plain", "Stopped");
  });

  server.begin();
}

void loop() {
  // Handle other actions like servo movement in response to app commands
}

This code is designed to run on the ESP32 microcontroller. It sets up Wi-Fi connectivity, a web server, and defines routes for controlling the motors and servos. The stopMotors function is used to stop all motors, and the setup function initializes the system and connects to Wi-Fi. The loop function is left empty, as the primary control is handled via web server routes.