How to Make Remote Control Car

Description

This project is a complete step-by-step guide to building your own remote control car using an Arduino UNO, an L298N motor driver, and a FlySky FS-CT6B transmitter with FS-R6B receiver. Unlike Bluetooth-controlled builds, this car is controlled using RC radio signals, giving smoother and more responsive control similar to hobby RC vehicles.

The Arduino reads PWM signals from the FlySky receiver's channels and converts them into motor movement — controlling forward, backward, left, and right turns through the L298N driver. This project is a great way to learn about RC receiver signal processing, PWM decoding using pulseIn(), and real-time motor control logic.

Components Required

Component	Quantity
Arduino UNO	1
L298N Motor Driver	1
BO Motors	4
BO Motor Tyres	4
12V Battery	1
FlySky FS-CT6B Transmitter	1
FlySky FS-R6B Receiver	1
Cardboard (Chassis)	1
Switch	1
Wires	As required
Jumper Wires	As required

Pin Connection Table

L298N Motor Driver → Arduino UNO

L298N Pin	Arduino Pin
IN1	D8
IN2	D9
IN3	D10
IN4	D11
5V	VIN
GND	GND

Battery → L298N Motor Driver

Battery	L298N Terminal
Positive (+)	12V Input
Negative (−)	GND

FlySky FS-R6B Receiver → Arduino UNO

Receiver Pin	Arduino Pin
5V	5V
GND	GND
Channel 1 (CH1)	A0
Channel 2 (CH2)	A1
Channel 3 (CH3)	A2
Channel 4 (CH4)	A3
Channel 5 (CH5)	A4
Channel 6 (CH6)	A5

Motor Output Connections

The two left-side BO motors are connected in parallel to the left output terminal (OUT1/OUT2) of the L298N, and the two right-side BO motors are connected in parallel to the right output terminal (OUT3/OUT4). Connecting each side's motors in parallel allows both wheels on that side to move together in sync.

Arduino Code

// Creative Inventions
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int in1 = 8;
int in2 = 9;
int in3 = 10;
int in4 = 11;

int receiver_pins[] = {A0,A1,A2,A3,A4,A5}; 
int receiver_values[] = {0, 0, 0, 0};

int res_min = 1100;
int res_max = 1900;

boolean prt = true;
int mode = 0;

void setup() {
  pinMode(11, OUTPUT);
  pinMode(12, OUTPUT);
  pinMode(13, OUTPUT);

  pinMode(in1, OUTPUT);
  pinMode(in2, OUTPUT);
  pinMode(in3, OUTPUT);
  pinMode(in4, OUTPUT);

  Serial.begin(115200);

  // Startup LED indication
  setLED(1); delay(300);
  setLED(2); delay(300);
  setLED(3); delay(300);
  setLED(0);
}

void loop() {
  receive();
  setModeLED();

  int rot = receiver_values[0];   // CH1 (Left/Right)
  int speed = receiver_values[1]; // CH2 (Forward/Backward)

  int m1 = 0;
  int m2 = 0;

  // -------- MOVEMENT LOGIC --------

  // Forward / Backward
  if (speed > 100) {
    m1 = 1;
    m2 = 1;
  }
  else if (speed < -100) {
    m1 = -1;
    m2 = -1;
  }

  // Turning (overrides forward/back)
  if (rot > 100) {        // Right
    m1 = 1;
    m2 = -1;
  }
  else if (rot < -100) {  // Left
    m1 = -1;
    m2 = 1;
  }

  mpower(1, m1);
  mpower(2, m2);
}

// ---------------- RECEIVE ----------------
int rp = 0;
void receive() {

  receiver_values[rp] = map(pulseIn(receiver_pins[rp], HIGH),
                           res_min, res_max, -255, 255);
  rp++;
  if (rp == 4) rp = 0;

  boolean activevalues = true;

  for (int i = 0; i < 4; i++) {
    if (prt) {
      Serial.print("CH"); Serial.print(i);
      Serial.print(": "); Serial.print(receiver_values[i]);
      Serial.print("  ");
    }
    if (receiver_values[i] < -500) {
      activevalues = false;
    }
  }

  mode = 0;

  if (!activevalues) {
    mode = -1;
  } else if (receiver_values[2] > -100) {
    mode = 2;
  } else if (receiver_values[3] > -100) {
    mode = 1;
  }

  if (prt) Serial.println();
}

// ---------------- LED ----------------
void setModeLED() {
  if (mode == -1) setLED(0);
  else if (mode == 0) setLED(1);
  else if (mode == 1) setLED(2);
  else if (mode == 2) setLED(3);
}

void setLED(int led) {
  for (int i = 1; i < 4; i++) {
    if (led == i) digitalWrite(10 + i, LOW);
    else digitalWrite(10 + i, HIGH);
  }
}

// ---------------- MOTOR CONTROL ----------------
void mpower(int motor, int dir) {

  int pA, pB;

  if (motor == 1) {
    pA = in1;
    pB = in2;
  } else {
    pA = in3;
    pB = in4;
  }

  if (dir == 1) {          // Forward
    digitalWrite(pA, HIGH);
    digitalWrite(pB, LOW);
  }
  else if (dir == -1) {    // Reverse
    digitalWrite(pA, LOW);
    digitalWrite(pB, HIGH);
  }
  else {                   // Stop
    digitalWrite(pA, LOW);
    digitalWrite(pB, LOW);
  }
}