Circuit Documentation

Summary

This circuit is designed to control a smart car using an Arduino UNO microcontroller and an L293D motor driver. The car's movement can be controlled via serial communication, which is handled by the Arduino UNO. The circuit includes a power supply consisting of two 18650 Li-ion batteries, a 7805 voltage regulator, and a diode for reverse voltage protection. An electrolytic capacitor is used for voltage smoothing. The motors and wheels are driven by the L293D motor driver, which receives control signals from the Arduino UNO.

Component List

Arduino UNO

• Microcontroller board based on the ATmega328P
• Used for controlling the smart car's motors and handling serial communication

L293D Motor Driver

• Quadruple high-current half-H driver
• Used to drive the motors of the smart car

18650 Li-ion Battery x 2

• Rechargeable battery providing power to the circuit

7805 Voltage Regulator

• Voltage regulator that outputs a stable 5V from a higher voltage input

Diode

• Used for reverse voltage protection

Electrolytic Capacitor

• Capacitance: 1000 Farads
• Used for voltage smoothing in the power supply

Motor and Wheels (x2)

• Actuators for the smart car's movement

Wiring Details

Arduino UNO

• GND connected to the common ground net
• Vin connected to the positive side of the Electrolytic Capacitor
• Digital pins D3 to D8 connected to the L293D motor driver control inputs

L293D Motor Driver

• gnd pins connected to the common ground net
• vss connected to the positive side of the Electrolytic Capacitor
• vs connected to the 7805 Vout
• enable 1, input 1, input 2, enable 2, input 3, and input 4 connected to Arduino UNO digital pins D3 to D8
• output 1, output 2, output 3, and output 4 connected to the respective motor and wheels

18650 Li-ion Battery x 2

• + connected to the anode of the Diode
• - connected to the common ground net

7805 Voltage Regulator

• Vin connected to the cathode of the Diode
• Gnd connected to the common ground net
• Vout connected to the vs of the L293D motor driver

Diode

• anode connected to the positive terminal of the 18650 Li-ion Battery x 2
• cathode connected to the Vin of the 7805 Voltage Regulator

Electrolytic Capacitor

• + connected to the Vin of the Arduino UNO and vss of the L293D motor driver
• - connected to the common ground net

Motor and Wheels

• Two sets of vcc and GND connected to the output 1, output 2, output 3, and output 4 of the L293D motor driver

Documented Code

/*
 * Smartcar with VC-02 AI Thinker
 * This Arduino sketch controls a smart car with motor drivers and a VC-02 module.
 * The car can be controlled via serial communication with the VC-02 module.
 */

// Pin definitions
const int motorEnable1 = 3;
const int motorInput1 = 4;
const int motorInput2 = 5;
const int motorEnable2 = 6;
const int motorInput3 = 7;
const int motorInput4 = 8;

void setup() {
  // Initialize serial communication
  Serial.begin(9600);

  // Initialize motor control pins
  pinMode(motorEnable1, OUTPUT);
  pinMode(motorInput1, OUTPUT);
  pinMode(motorInput2, OUTPUT);
  pinMode(motorEnable2, OUTPUT);
  pinMode(motorInput3, OUTPUT);
  pinMode(motorInput4, OUTPUT);

  // Set initial motor states
  digitalWrite(motorEnable1, LOW);
  digitalWrite(motorInput1, LOW);
  digitalWrite(motorInput2, LOW);
  digitalWrite(motorEnable2, LOW);
  digitalWrite(motorInput3, LOW);
  digitalWrite(motorInput4, LOW);
}

void loop() {
  // Check if data is available from VC-02 module
  if (Serial.available() > 0) {
    char command = Serial.read();
    handleCommand(command);
  }
}

void handleCommand(char command) {
  switch (command) {
    case 'F': // Move forward
      digitalWrite(motorEnable1, HIGH);
      digitalWrite(motorInput1, HIGH);
      digitalWrite(motorInput2, LOW);
      digitalWrite(motorEnable2, HIGH);
      digitalWrite(motorInput3, HIGH);
      digitalWrite(motorInput4, LOW);
      break;
    case 'B': // Move backward
      digitalWrite(motorEnable1, HIGH);
      digitalWrite(motorInput1, LOW);
      digitalWrite(motorInput2, HIGH);
      digitalWrite(motorEnable2, HIGH);
      digitalWrite(motorInput3, LOW);
      digitalWrite(motorInput4, HIGH);
      break;
    case 'L': // Turn left
      digitalWrite(motorEnable1, HIGH);
      digitalWrite(motorInput1, LOW);
      digitalWrite(motorInput2, HIGH);
      digitalWrite(motorEnable2, HIGH);
      digitalWrite(motorInput3, HIGH);
      digitalWrite(motorInput4, LOW);
      break;
    case 'R': // Turn right
      digitalWrite(motorEnable1, HIGH);
      digitalWrite(motorInput1, HIGH);
      digitalWrite(motorInput2, LOW);
      digitalWrite(motorEnable2, HIGH);
      digitalWrite(motorInput3, LOW);
      digitalWrite(motorInput4, HIGH);
      break;
    case 'S': // Stop
      digitalWrite(motorEnable1, LOW);
      digitalWrite(motorEnable2, LOW);
      break;
    default:
      // Unknown command
      break;
  }
}

This code is responsible for interpreting commands received via serial communication and controlling the motors accordingly. The commands 'F', 'B', 'L', 'R', and 'S' correspond to forward, backward, left, right, and stop movements of the smart car.