Wireless Joystick controlled Robot Car using Arduino, 433Mhz RF and L298N Motor Driver

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Table of Contents

Description:

Wireless Joystick controlled Robot Car using Arduino– In this tutorial, you will learn how to control a Robot Car wirelessly using Arduino, L298N Motor driver, and 433 Mhz RF transmitter and Receiver. The robot control system can be activated and de-activated using the Built-in Joystick push Button.

Depending on the movement of the joystick and the value of the VRx and VRy, the speed of the dc motors can be controlled in realTime which gives you more control over the Robot Car….

This is the 2^nd version of the Robot Car.

While in the first version I used an Android cell phone to control the Robot Car using the HC-05 Bluetooth module.

This Tutorial is based on my previous two tutorials.

in this tutorial I explained, how to assemble the robot parts and how to use the L298N motor driver to control the forward, left , right and reverse movement. In this tutorial, I also explained how to control the speed of a dc motor using the pulse width modulation.

While in this tutorial I explained the joystick pinouts, its basic working principle, its interfacing with Arduino, and basic programming to control some led’s depending on the movement of the joystick… If you are a beginner and you have never used the Joystick module and L298N motor driver then I highly recommend you should first watch these tutorials and then you can resume from here.

You know the Transmitter and receiver modules used for controlling the Robot Car offer short-range wireless communication. If you want to increase the range up to 1Km then watch my tutorial on the NRFL01 Transceiver Modules.

Amazon Links:

Arduino Nano USB-C Type (Recommended)

Robot Car chassis kit:

L298N motor driver:

2-Axis Analog Joystick

433 MHz Transmitter and Receiver Modules:

Arduino Uno

*Disclosure: These are affiliate links. As an Amazon Associate I earn from qualifying purchases.

wireless joystick Interfacing:

Watch this tutorial for the robot parts assembling and connections.

All the connections are exactly the same as explained in my previous tutorial. The only modification that I did is the addition of the 433 Mhz RF receiver module…the VCC pin of the receiver module is connected with the 5 volts…the ground pin of the receiver is connected with the Arduino’s ground…while the data pin of the receiver is connected with pin number 3 of the Arduino… everything else remains the same as explained in the getting started tutorial…

This is the Joystick Transmitter Side, the 433 Mhz RF transmitter VCC pin is connected with the Arduino’s 5 volts, the ground pin of the transmitter is connected with the Arduino ground while the data pin is connected with the Arduino’s pin number 12…

as you can see I have also solder wire with the transmitter to slightly increase the range…while the joystick connections are exactly the same as explained in the joystick getting started tutorial.

wireless joystick-controlled Robot Car Arduino Programming:

wireless joystick Robot Car Transmitter Arduino Programming:

// Robot Transmitter programming
#include <VirtualWire.h>
const int transmit_pin = 12;

 String str;
 char cstr[100];
String message = "";
unsigned int mlength; // message length 

// for joystick
 int flag = 0; 
int buttonf = 0; 
int power = 7; 
int button = 4; 
int vrx = A1; 
int vry = A2;

 int xdata = 0; 
 int ydata = 0; 
void setup()
{
      // Initialise the IO and ISR
    vw_set_tx_pin(transmit_pin);
     vw_setup(2000);       // Bits per sec
  Serial.begin(9600);
  
  pinMode(vrx, INPUT); 
  pinMode(vry, INPUT); 
  pinMode(power, OUTPUT); 
  digitalWrite(power, HIGH); 

  pinMode(button, INPUT); 
  digitalWrite(button , HIGH);
}

void loop()
{
  control();

   if( buttonf == 1)
   {
  xdata = analogRead(vrx); 
  ydata = analogRead(vry); 
 //Serial.println(xdata);
 //Serial.println(ydata);
SendData(xdata,ydata,buttonf); 
//delay(100);
   }
   
   if(buttonf == 0)
   {
    SendData(0,0,0); // send 0 to the receiver.
    delay(100); 
   }
                
}

// this function takes 5 arguments as the input
// the sensors and the sensors group number. 
// let's say we are using multiple sensors, the sensors 
//can be divided into groups. 
void SendData( int xvalue,int yvalue,int buttonstatus)
{

message = message + xvalue +"," + yvalue + "," + buttonstatus ;
mlength = message.length(); // find the number of characters in a message.
  str = message;
  str.toCharArray(cstr,100);
  vw_send((uint8_t *)cstr, mlength); // 
  vw_wait_tx(); // Wait until the whole message is gone
  str = "";
  message = ""; 

}


void control()
{
if (( digitalRead(button) == LOW ) && (buttonf == 0))
{

   Serial.println(" Started");  
  buttonf = 1; 
  delay(1000);
 
}

if (( digitalRead(button) == LOW ) && (buttonf == 1))
{
 
  Serial.println("ended"); 
  buttonf = 0; 
  delay(1000); 
}
 digitalWrite(button , HIGH);
}

// Robot Transmitter programming

#include <VirtualWire.h>

const int transmit_pin = 12;

String str;

char cstr[100];

String message = "";

unsigned int mlength; // message length

// for joystick

int flag = 0;

int buttonf = 0;

int power = 7;

int button = 4;

int vrx = A1;

int vry = A2;

int xdata = 0;

int ydata = 0;

void setup()

{

// Initialise the IO and ISR

vw_set_tx_pin(transmit_pin);

vw_setup(2000); // Bits per sec

Serial.begin(9600);

pinMode(vrx, INPUT);

pinMode(vry, INPUT);

pinMode(power, OUTPUT);

digitalWrite(power, HIGH);

pinMode(button, INPUT);

digitalWrite(button , HIGH);

}

void loop()

{

control();

if( buttonf == 1)

{

xdata = analogRead(vrx);

ydata = analogRead(vry);

//Serial.println(xdata);

//Serial.println(ydata);

SendData(xdata,ydata,buttonf);

//delay(100);

}

if(buttonf == 0)

{

SendData(0,0,0); // send 0 to the receiver.

delay(100);

}

// this function takes 5 arguments as the input

// the sensors and the sensors group number.

// let's say we are using multiple sensors, the sensors

//can be divided into groups.

void SendData( int xvalue,int yvalue,int buttonstatus)

{

message = message + xvalue +"," + yvalue + "," + buttonstatus ;

mlength = message.length(); // find the number of characters in a message.

str = message;

str.toCharArray(cstr,100);

vw_send((uint8_t *)cstr, mlength); //

vw_wait_tx(); // Wait until the whole message is gone

str = "";

message = "";

}

void control()

{

if (( digitalRead(button) == LOW ) && (buttonf == 0))

{

Serial.println(" Started");

buttonf = 1;

delay(1000);

}

if (( digitalRead(button) == LOW ) && (buttonf == 1))

{

Serial.println("ended");

buttonf = 0;

delay(1000);

}

digitalWrite(button , HIGH);

}

wireless joystick Receiver Arduino Programming:

// receiver Programming

#include <VirtualWire.h>


const int receive_pin = 3;

String message; 
String myString;

// for joystick
int xvalue; 
int yvalue;
int buttonf;
int xdata; 
int ydata; 
int bfdata; // buttonflag 

// for L298N motor driver
int ena = 5; 
int enb = 6; 

int in1 = 8; 
int in2 = 9; 
int in3 = 10; 
int in4 = 11;
 

void setup()
{
    delay(1000);
    Serial.begin(9600); // Debugging only
  pinMode(ena, OUTPUT); 
  pinMode(enb, OUTPUT); 

  pinMode(in1, OUTPUT); 
  pinMode(in2, OUTPUT);
  pinMode(in3, OUTPUT);
  pinMode(in4, OUTPUT);
  
 analogWrite(ena, 0); 
 analogWrite(enb, 0);
 delay(1000);

    
    Serial.println("setup");

    // Initialise the IO and ISR

    vw_set_rx_pin(receive_pin);

    vw_set_ptt_inverted(true); // Required for DR3100
    vw_setup(2000);  // Bits per sec

    vw_rx_start();       // Start the receiver PLL running

}

void loop()
{
    uint8_t buf[VW_MAX_MESSAGE_LEN];
    uint8_t buflen = VW_MAX_MESSAGE_LEN;

    if (vw_get_message(buf, &buflen)) // Non-blocking
    {
    int i;

     
    // Message with a good checksum received, dump it.
    //Serial.print("Got: ");
    
    for (i = 0; i < buflen; i++)
    {
        char c = (buf[i]);
            message = message + c ; // make a message from the received characters         
    }
  myString = message; 
    Serial.println(message);

String l = getValue(myString, ',', 0); // xvalue
String m = getValue(myString, ',', 1); // yvalue
String n = getValue(myString, ',', 2); // buttonf


xdata = l.toInt();
ydata = m.toInt();
bfdata = n.toInt();

/*
Serial.println("*********from Transmitter************"); 
Serial.println(xdata);  
Serial.println(ydata);
Serial.println(bfdata);
*/

/*
 when the joystic is at normal position we get 
 x = 450 to 550
 y= 450 to 550
 for the these values we want the robot not to move
 */

 if ( ((xdata >= 480)&&(xdata <= 510)) && ( (ydata>=480) && (ydata<=510) ) )
 {
  Serial.println("Stopped"); 
   analogWrite(ena, 0); 
   analogWrite(enb, 0);
  digitalWrite(in1, LOW); 
  digitalWrite(in2, LOW);
  digitalWrite(in3, LOW);
  digitalWrite(in4, LOW);
 }

 // if button on the joystick is pressed

 if (bfdata == 0)
 {
   analogWrite(ena, 0); 
   analogWrite(enb, 0);
  digitalWrite(in1, LOW); 
  digitalWrite(in2, LOW);
  digitalWrite(in3, LOW);
  digitalWrite(in4, LOW);
  
 }

 /* for the forward movement
  *  the value of the x increases above 550 to 1023 while the value of the y statys between 450 and 550
  */

 if ( ((xdata > 510)&&(xdata <= 1023)) && ( (ydata>=480) && (ydata<=510) ) )
 {
   Serial.println("forward"); 
   int xmapped = map(xmapped, xdata, 1023, 255,0);
   int ymapped = map(ymapped, xdata, 1023, 255,0);
   analogWrite(ena, xmapped); 
   analogWrite(enb, ymapped);

  digitalWrite(in1, HIGH); 
  digitalWrite(in2, LOW);
  digitalWrite(in3, LOW);
  digitalWrite(in4, HIGH);
 }


 /* for the Reverse movement
  *  the value of the x increases above 550 to 1023 while the value of the y statys between 450 and 550
  */

 if ( ((xdata >= 0)&&(xdata < 480)) && ( (ydata>=480) && (ydata<=510) ) )
 {
   Serial.println("reverse");
   int xmapped = map(xmapped, xdata, 479, 255,0);
   int ymapped = map(ymapped, xdata, 479, 255,0);
   analogWrite(ena, xmapped); 
   analogWrite(enb, ymapped);

  digitalWrite(in1, LOW); 
  digitalWrite(in2, HIGH);
  digitalWrite(in3, HIGH);
  digitalWrite(in4, LOW);

 }

 // for right movement
 if (  ( (ydata> 510) && (ydata <= 1023) ) && ( bfdata == 1) )
 {
   Serial.println("Right");
   int ymapped = map(ymapped, ydata, 1023, 255,0);
   analogWrite(ena, ymapped); 
   analogWrite(enb, 0);

  digitalWrite(in1, HIGH); 
  digitalWrite(in2, LOW);
  digitalWrite(in3, LOW);
  digitalWrite(in4, LOW);

 }

  // for left movement
 if (  ( (ydata >= 0) && (ydata <= 479) && ( bfdata == 1) ) )
 {
   Serial.println("left");
   int ymapped = map(ymapped, ydata, 479, 255,0);
   analogWrite(ena, 0); 
   analogWrite(enb, ymapped);

digitalWrite(in1, LOW); 
  digitalWrite(in2, LOW);
  digitalWrite(in3, LOW);
  digitalWrite(in4, HIGH);
 

 }

 
     message = "";
    }
    

}


String getValue(String data, char separator, int index)
{
    int found = 0;
    int strIndex[] = { 0, -1 };
    int maxIndex = data.length() - 1;

    for (int i = 0; i <= maxIndex && found <= index; i++) {
        if (data.charAt(i) == separator || i == maxIndex) {
            found++;
            strIndex[0] = strIndex[1] + 1;
            strIndex[1] = (i == maxIndex) ? i+1 : i;
        }
    }
    return found > index ? data.substring(strIndex[0], strIndex[1]) : "";
}

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// receiver Programming

#include <VirtualWire.h>

const int receive_pin = 3;

String message;

String myString;

// for joystick

int xvalue;

int yvalue;

int buttonf;

int xdata;

int ydata;

int bfdata; // buttonflag

// for L298N motor driver

int ena = 5;

int enb = 6;

int in1 = 8;

int in2 = 9;

int in3 = 10;

int in4 = 11;

void setup()

{

delay(1000);

Serial.begin(9600); // Debugging only

pinMode(ena, OUTPUT);

pinMode(enb, OUTPUT);

pinMode(in1, OUTPUT);

pinMode(in2, OUTPUT);

pinMode(in3, OUTPUT);

pinMode(in4, OUTPUT);

analogWrite(ena, 0);

analogWrite(enb, 0);

delay(1000);

Serial.println("setup");

// Initialise the IO and ISR

vw_set_rx_pin(receive_pin);

vw_set_ptt_inverted(true); // Required for DR3100

vw_setup(2000); // Bits per sec

vw_rx_start(); // Start the receiver PLL running

}

void loop()

{

uint8_t buf[VW_MAX_MESSAGE_LEN];

uint8_t buflen = VW_MAX_MESSAGE_LEN;

if (vw_get_message(buf, &buflen)) // Non-blocking

{

int i;

// Message with a good checksum received, dump it.

//Serial.print("Got: ");

for (i = 0; i < buflen; i++)

{

char c = (buf[i]);

message = message + c ; // make a message from the received characters

}

myString = message;

Serial.println(message);

String l = getValue(myString, ',', 0); // xvalue

String m = getValue(myString, ',', 1); // yvalue

String n = getValue(myString, ',', 2); // buttonf

xdata = l.toInt();

ydata = m.toInt();

bfdata = n.toInt();

Serial.println("*********from Transmitter************");

Serial.println(xdata);

Serial.println(ydata);

Serial.println(bfdata);

when the joystic is at normal position we get

x = 450 to 550

y= 450 to 550

for the these values we want the robot not to move

if ( ((xdata >= 480)&&(xdata <= 510)) && ( (ydata>=480) && (ydata<=510) ) )

{

Serial.println("Stopped");

analogWrite(ena, 0);

analogWrite(enb, 0);

digitalWrite(in1, LOW);

digitalWrite(in2, LOW);

digitalWrite(in3, LOW);

digitalWrite(in4, LOW);

}

// if button on the joystick is pressed

if (bfdata == 0)

{

analogWrite(ena, 0);

analogWrite(enb, 0);

digitalWrite(in1, LOW);

digitalWrite(in2, LOW);

digitalWrite(in3, LOW);

digitalWrite(in4, LOW);

}

/* for the forward movement

* the value of the x increases above 550 to 1023 while the value of the y statys between 450 and 550

if ( ((xdata > 510)&&(xdata <= 1023)) && ( (ydata>=480) && (ydata<=510) ) )

{

Serial.println("forward");

int xmapped = map(xmapped, xdata, 1023, 255,0);

int ymapped = map(ymapped, xdata, 1023, 255,0);

analogWrite(ena, xmapped);

analogWrite(enb, ymapped);

digitalWrite(in1, HIGH);

digitalWrite(in2, LOW);

digitalWrite(in3, LOW);

digitalWrite(in4, HIGH);

}

/* for the Reverse movement

* the value of the x increases above 550 to 1023 while the value of the y statys between 450 and 550

if ( ((xdata >= 0)&&(xdata < 480)) && ( (ydata>=480) && (ydata<=510) ) )

{

Serial.println("reverse");

int xmapped = map(xmapped, xdata, 479, 255,0);

int ymapped = map(ymapped, xdata, 479, 255,0);

analogWrite(ena, xmapped);

analogWrite(enb, ymapped);

digitalWrite(in1, LOW);

digitalWrite(in2, HIGH);

digitalWrite(in3, HIGH);

digitalWrite(in4, LOW);

}

// for right movement

if ( ( (ydata> 510) && (ydata <= 1023) ) && ( bfdata == 1) )

{

Serial.println("Right");

int ymapped = map(ymapped, ydata, 1023, 255,0);

analogWrite(ena, ymapped);

analogWrite(enb, 0);

digitalWrite(in1, HIGH);

digitalWrite(in2, LOW);

digitalWrite(in3, LOW);

digitalWrite(in4, LOW);

}

// for left movement

if ( ( (ydata >= 0) && (ydata <= 479) && ( bfdata == 1) ) )

{

Serial.println("left");

int ymapped = map(ymapped, ydata, 479, 255,0);

analogWrite(ena, 0);

analogWrite(enb, ymapped);

digitalWrite(in1, LOW);

digitalWrite(in2, LOW);

digitalWrite(in3, LOW);

digitalWrite(in4, HIGH);

}

message = "";

}

String getValue(String data, char separator, int index)

{

int found = 0;

int strIndex[] = { 0, -1 };

int maxIndex = data.length() - 1;

for (int i = 0; i <= maxIndex && found <= index; i++) {

if (data.charAt(i) == separator || i == maxIndex) {

found++;

strIndex[0] = strIndex[1] + 1;

strIndex[1] = (i == maxIndex) ? i+1 : i;

}

return found > index ? data.substring(strIndex[0], strIndex[1]) : "";

}

Watch Video Tutorial:

4 Comments

Jonatan Esteve callejas says:

September 26, 2021 at 1:21 am

hola muy buenas 1 felicitarte por tu trabajo ojala estuviese en español . xd tengo un problemas con esta parte del código
vw_set_ptt_inverted(true); // Required for DR3100

francisco Rodríguez López says:

August 15, 2022 at 4:31 pm

Hi, I saw your assembly, I like it a lot so I can give it to my granddaughters, but I have seen the code of the assembly, but if you could send me the circuit or diagram of the assembly, it would be very good.
Thank you very much in advance, greetings

francisco Rodríguez López says:

August 15, 2022 at 6:22 pm

could you pass me the circuit or diagram crap to assemble for my granddaughters and I have seen the code or drive but I have not seen all the connections greetings and thank you very much in advance

Michael Aspegren says:

December 6, 2022 at 8:09 pm

Hello there, I am intrigued by the code. Could you please clear up what “buttonf” is exactly and how it actually changes state. I am assuming its the state the button is in.

Many Thanks