Bluetooth Wireless Bot

It's an Android app controlled bot. The Bluetooth module will receive signals via App and then give output accordingly.

IntermediateShowcase (no instructions)2 hours3,005

Things used in this project

Hardware components

Arduino UNO

HC-05 Bluetooth Module

Texas Instruments Dual H-Bridge motor drivers L293D

9V battery (generic)

Jumper wires (generic)

Software apps and online services

Arduino IDE

Story

This is an Android App controlled bot. The app used is Sena BTerm, easily and freely available on Google PlayStore: https://play.google.com/store/apps/details?id=com.sena.bterm&hl=e

Hardware:

Firstly, we use HC-05 Bluetooth Module. Connect the GND and +5V pins of Module to respective pins of Arduino UNO. Then connect the Tx Pin of Module to Rx pin of Arduino. This is because Tx means Transmit and Rx mean Receive.The data transmitted by the Module will be received by the Arduino and vice-versa. Connect the Rx Pin of Module to Tx Pin of Arduino.

Now connection of motors. Connect the L239D Motor Driver Module to the motor and Arduino as shown. Connect the input side of Motor Driver to PWM pins 6, 9, 10, 11 of Arduino. Connect 12v battery or two 9v battery in series as input to the motor. Connect the Left Motor pin and Right Motor pins to motors of chassis.

Software:

The code is uploaded on the site. Basically, we use the keys e, a, s, d, w, x of the keypad to control the bot. The specification of keys is in the code. We use PWM input of Arduino since we want to control the speed of the bot.

Bluetooth

int LmotorUp = 10; //initialising Arduino port 10 be be called as LmotorUp
int LmotorDn = 11; //initialising Arduino port 11 be be called as LmotorDn
int RmotorUp = 6;  //initialising Arduino port 6 be be called as RmotorUp
int RmotorDn = 9;  //initialising Arduino port 9 be be called as RmotorDn

void setup()
{
  Serial.begin(9600);
  pinMode(LmotorUp,OUTPUT);//Setting ports as OUTPUTS as they 
  pinMode(LmotorDn,OUTPUT);//supply signal values to motor driver
  pinMode(RmotorUp,OUTPUT);
  pinMode(RmotorDn,OUTPUT);

  
  Serial.println("Team ONYX Welcomes you"); //begining statement because i can :P
  delay(1000);
} 
  

void loop()
{
  if(Serial.available()>0)//Checking is Serial data available
  {
    int input = Serial.read(); //Storing value of read data into variable assigned
    switch(input)
    {
     case 'e' : MoveSlow(); //Move slow in forward direction
     break;
     case 'w' : MoveF(); //Calling respective functions if mathced with case label 
     break;
     case 's' : MoveB(); // here is it important to use '' as that stores the ASCII value is the letter in the variable
     break;
     case 'a' : MoveL(); // and hence we can use the int keyword
     break;
     case 'd' : MoveR();
     break;
     case 'x' : Stop();
     break;
     default : break;
    }
  } 
  delay(1);
}

void MoveF()
{
  Serial.println("Team ONYX Forward");
  digitalWrite(LmotorUp,HIGH); //We are writing a Digital HIGH to the upper left pin of the motor driver
  digitalWrite(LmotorDn,LOW); //We are writing a Digital LOW to the lower left pin of the motor driver
  digitalWrite(RmotorUp,HIGH); //We are writing a Digital HIGH to the upper right pin of the motor driver
  digitalWrite(RmotorDn,LOW); //We are writing a Digital LOW to the lower right pin of the motor driver
   // As a result the robot will move forward
}

void MoveB()
{
  Serial.println("Team ONYX Backward");
  digitalWrite(LmotorUp,LOW); //Reverse logic of above
  digitalWrite(LmotorDn,HIGH);
  digitalWrite(RmotorUp,LOW);
  digitalWrite(RmotorDn,HIGH);
}

void MoveL()
{
  Serial.println("Team ONYX Left");
  digitalWrite(LmotorUp,LOW); 
  analogWrite(LmotorDn,190); //this will cause the robot to move left
  digitalWrite(RmotorUp,HIGH);
  digitalWrite(RmotorDn,LOW);
}

void MoveR()
{
  Serial.println("Team ONYX Right");
  digitalWrite(LmotorUp,HIGH);
  digitalWrite(LmotorDn,LOW);//this will cause the robot to move right
  digitalWrite(RmotorUp,LOW);
  analogWrite(RmotorDn,190);
}

void Stop()
{
  Serial.println("Team ONYX Stop");
  digitalWrite(LmotorUp,LOW);//Writing a digital LOW to all pins associated with movement of motor driver causes all motors to stop
  digitalWrite(LmotorDn,LOW);
  digitalWrite(RmotorUp,LOW);
  digitalWrite(RmotorDn,LOW);
}
 void MoveSlow()
{
  Serial.println("Team ONYX Stop");
  analogWrite(LmotorUp,190);
  digitalWrite(LmotorDn,LOW); 
  analogWrite(RmotorUp,190);
  digitalWrite(RmotorDn,LOW);
}

Bluetooth Wireless Bot