Bluetooth ESP32 4WD Car

#include <Arduino.h>
// ============================================================
//  4WD Bluetooth Car — ESP32 + 2x L298N
//  Layout:
//    L298N_LEFT  CHA (ENA) → Front-Left motor (OUT1/OUT2)
//                CHB (ENB) → Rear-Left  motor (OUT3/OUT4)
//    L298N_RIGHT CHA (ENA) → Front-Right motor (OUT1/OUT2)
//                CHB (ENB) → Rear-Right motor (OUT3/OUT4)
//
//  Bluetooth commands (send via serial BT terminal):
//    F = Forward    B = Backward
//    L = Turn Left  R = Turn Right
//    S = Stop
//    0-9 = speed (0=0% … 9=100%)
// ============================================================

#include "BluetoothSerial.h"

// ---- Pin definitions ----
#define LEFT_IN1  27
#define LEFT_IN2  26
#define LEFT_IN3  25
#define LEFT_IN4  33
#define LEFT_ENA  14
#define LEFT_ENB  13

#define RIGHT_IN1 32
#define RIGHT_IN2 23
#define RIGHT_IN3 22
#define RIGHT_IN4 21
#define RIGHT_ENA 19
#define RIGHT_ENB 18

// ---- LEDC PWM channels ----
#define CH_LEFT_A  0
#define CH_LEFT_B  1
#define CH_RIGHT_A 2
#define CH_RIGHT_B 3

#define PWM_FREQ   1000
#define PWM_RES    8        // 8-bit → 0-255


// Forward declarations
void setLeft(bool fwd, int spd);
void setRight(bool fwd, int spd);
void stopAll();

BluetoothSerial SerialBT;

int speed = 200;  // default speed (0-255)

// ---- Helpers ----
void setLeft(bool fwd, int spd) {
  digitalWrite(LEFT_IN1, fwd ? HIGH : LOW);
  digitalWrite(LEFT_IN2, fwd ? LOW  : HIGH);
  digitalWrite(LEFT_IN3, fwd ? HIGH : LOW);
  digitalWrite(LEFT_IN4, fwd ? LOW  : HIGH);
  ledcWrite(CH_LEFT_A, spd);
  ledcWrite(CH_LEFT_B, spd);
}

void setRight(bool fwd, int spd) {
  digitalWrite(RIGHT_IN1, fwd ? HIGH : LOW);
  digitalWrite(RIGHT_IN2, fwd ? LOW  : HIGH);
  digitalWrite(RIGHT_IN3, fwd ? HIGH : LOW);
  digitalWrite(RIGHT_IN4, fwd ? LOW  : HIGH);
  ledcWrite(CH_RIGHT_A, spd);
  ledcWrite(CH_RIGHT_B, spd);
}

void stopAll() {
  digitalWrite(LEFT_IN1,  LOW); digitalWrite(LEFT_IN2,  LOW);
  digitalWrite(LEFT_IN3,  LOW); digitalWrite(LEFT_IN4,  LOW);
  digitalWrite(RIGHT_IN1, LOW); digitalWrite(RIGHT_IN2, LOW);
  digitalWrite(RIGHT_IN3, LOW); digitalWrite(RIGHT_IN4, LOW);
  ledcWrite(CH_LEFT_A,  0); ledcWrite(CH_LEFT_B,  0);
  ledcWrite(CH_RIGHT_A, 0); ledcWrite(CH_RIGHT_B, 0);
}

void setup() {
  Serial.begin(115200);
  SerialBT.begin("4WD_Car");
  Serial.println("Bluetooth started — pair with '4WD_Car'");

  // Direction pins
  int dirPins[] = {LEFT_IN1, LEFT_IN2, LEFT_IN3, LEFT_IN4,
                   RIGHT_IN1, RIGHT_IN2, RIGHT_IN3, RIGHT_IN4};
  for (int p : dirPins) {
    pinMode(p, OUTPUT);
    digitalWrite(p, LOW);
  }

  // PWM (EN pins via LEDC)
  ledcSetup(CH_LEFT_A,  PWM_FREQ, PWM_RES);
  ledcSetup(CH_LEFT_B,  PWM_FREQ, PWM_RES);
  ledcSetup(CH_RIGHT_A, PWM_FREQ, PWM_RES);
  ledcSetup(CH_RIGHT_B, PWM_FREQ, PWM_RES);
  ledcAttachPin(LEFT_ENA,  CH_LEFT_A);
  ledcAttachPin(LEFT_ENB,  CH_LEFT_B);
  ledcAttachPin(RIGHT_ENA, CH_RIGHT_A);
  ledcAttachPin(RIGHT_ENB, CH_RIGHT_B);

  stopAll();
}

void loop() {
  if (SerialBT.available()) {
    char cmd = (char)SerialBT.read();

    // Speed adjustment: '0'-'9'
    if (cmd >= '0' && cmd <= '9') {
      speed = map(cmd - '0', 0, 9, 0, 255);
      SerialBT.printf("Speed set to %d%%\n", (speed * 100) / 255);
      return;
    }

    switch (cmd) {
      case 'F': case 'f':
        setLeft(true, speed);
        setRight(true, speed);
        SerialBT.println("Forward");
        break;

      case 'B': case 'b':
        setLeft(false, speed);
        setRight(false, speed);
        SerialBT.println("Backward");
        break;

      case 'L': case 'l':
        // Pivot left: right side forward, left side backward
        setLeft(false, speed);
        setRight(true,  speed);
        SerialBT.println("Turn Left");
        break;

      case 'R': case 'r':
        // Pivot right: left side forward, right side backward
        setLeft(true,  speed);
        setRight(false, speed);
        SerialBT.println("Turn Right");
        break;

      case 'S': case 's':
        stopAll();
        SerialBT.println("Stop");
        break;

      default:
        break;
    }
  }
}