ArduinoArduino Projects

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

wireless joystick

Description:

wireless joystick-In this project, 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.

wireless joystick

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….

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.



The Amazon Purchase links are given below:

Robot Car chassis kit: https://amzn.to/2tTpkgo
L298N dual H-Bridge motor driver: https://amzn.to/2XF4sam
Joystick: https://amzn.to/2E2Q0kI 
433Mhz tx and rx: best offer https://amzn.to/2EkVMyN
Arduino Uno: https://amzn.to/39aq6ZT
Mega 2560: https://amzn.to/2SszMsI
lm7805 Voltage Regulator: https://amzn.to/2ERYoTJ
330-ohm resistors pack: https://amzn.to/2Qj1Igg
female DC power jack socket: https://amzn.to/377Pg9M
470uf capacitors: https://amzn.to/2MrN3xR
5×7 cm Vero board: https://amzn.to/37b7KWO
female headers: https://amzn.to/350w6RE
connection wires: https://amzn.to/2MvOJXd
Super Starter kit for Beginners: https://amzn.to/398dliF
Jumper Wires: https://amzn.to/2SrnBwo
Bread Board: https://amzn.to/2MxV5FM
12v Adaptor: https://amzn.to/2MuOlZk
PCB plate: https://amzn.to/2MuwNMB
Variable Supply: https://amzn.to/39d0KdP
Digital Multimeter: https://amzn.to/34WbVoa
Vero Board / stripboard: https://amzn.to/39nL9Zg
Soldering iron kit: “best” You guys should definitely purchase this: https://amzn.to/2PVwexF
Solder wire: https://amzn.to/2QlOvTS
Wire Stripper: https://amzn.to/353tYJa
wirecutter: https://amzn.to/2tV2lFj
PCB small portable drill machine: https://amzn.to/2MvQqnx

DISCLAIMER:

Please Note: these are affiliate links. I may make a commission if you buy the components through these links. I would appreciate your support in this way!

Interfacing:

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…

wireless joystick

as you can see I have also solder a 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…


Programming:

In this project two Programs are used, one program is written for the Transmitter side and another program is written for the Receiver side. So first let’s start with the Transmitter side. In both the Programming the Virtual Wire library is used which you can download by clicking on the download button below.

wireless joystick Transmitter 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);
}



wireless joystick Receiver 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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