Bluetooth Controlled Car and Obstacle Avoiding Robot

Projects Programming
1

I want to make a obstacle avoiding robot with a bluetooth control. Heres the code:

#include <AFMotor.h>  
#include <NewPing.h>
#include <Servo.h> 
#include <SoftwareSerial.h>
#include <LiquidCrystal_I2C.h>

#define STATE_PIN A5 

SoftwareSerial bluetoothSerial(9, A4); // RX, TX

int speed = 255;
AF_DCMotor motor1(1, MOTOR12_1KHZ);
AF_DCMotor motor2(2, MOTOR12_1KHZ);
AF_DCMotor motor3(3, MOTOR34_1KHZ);
AF_DCMotor motor4(4, MOTOR34_1KHZ);
Servo myservo;   

#define TRIG_PIN A1 
#define ECHO_PIN A0 
#define MAX_DISTANCE 200 
#define MAX_SPEED 190 // sets speed of DC  motors
#define MAX_SPEED_OFFSET 20

NewPing sonar(TRIG_PIN, ECHO_PIN, MAX_DISTANCE); 

boolean goesForward=false;
int distance = 100;
int speedSet = 0;

void setup() {
  pinMode(STATE_PIN, INPUT);
  pinMode(buzzerPin, OUTPUT);
  pinMode(frontLightPin, OUTPUT);
  pinMode(backLightPin, OUTPUT);
  bluetoothSerial.begin(9600);  // Set the baud rate to your Bluetooth module.
  myservo.attach(10);  
  myservo.write(115); 
  delay(2000);
  distance = readPing();
  delay(100);
  distance = readPing();
  delay(100);
  distance = readPing();
  delay(100);
  distance = readPing();
  delay(100);
}

void loop() {
    if(digitalRead(STATE_PIN) == HIGH) {
        // If state pin is high (connected), control the car via Bluetooth
        controlCar();
    } else if (digitalRead(STATE_PIN) == LOW){
        // If state pin is low (disconnected), perform obstacle avoidance
        performObstacleAvoidance();
       
    }
}

void controlCar() {
    
    if (bluetoothSerial.available() > 0) {
        char command = bluetoothSerial.read();

        Stop(); // Initialize with motors stopped
        b = false;
        switch (command) {
          case 'F':
            forward(speed);
            break;
          case 'B':
            back(speed);
            b = true;
            break;
          case 'L':
            left(speed);
            break;
          case 'R':
            right(speed);
            break;
          case 'G':
            forwardLeft(speed);
            break;
          case 'I':
            forwardRight(speed);
            break;
          case 'H':
            backLeft(speed);
            break;
          case 'J':
            backRight(speed);
            break;
          case 'S': // Stop
            Stop();
            break;
          case 'W': // Front Lights On
            digitalWrite(frontLightPin, HIGH);
            frontLightOn = true;
            break;
          case 'w': // Front Lights Off
            digitalWrite(frontLightPin, LOW);
            frontLightOn = false;
            break;
          case 'U': // Back Lights On
            digitalWrite(backLightPin, HIGH);
            backLightOn = true;
            break;
          case 'u': // Back Lights Off
            digitalWrite(backLightPin, LOW);
            backLightOn = false;
            break;
          case 'V': // Horn On
            digitalWrite(buzzerPin, HIGH);
            break;
          case 'v': // Horn Off
            digitalWrite(buzzerPin, LOW);
            break;
          case 'X': // Extra On (Emergency blink)
            if (frontLightOn || backLightOn) {
              for (int i = 0; i < 5; i++) {
                digitalWrite(frontLightPin, HIGH);
                digitalWrite(backLightPin, HIGH);
                delay(500);
                digitalWrite(frontLightPin, LOW);
                digitalWrite(backLightPin, LOW);
                delay(500);
              }
            }
            break;
          case 'x': // Extra Off
            // No specific action needed for Extra Off
            break;
          case '0'...'9':
            setSpeed(command - '0' * 50);
            break;
          case 'q':
            setSpeed(255); // Maximum speed
            break;
          case 'D':
            StopAll();
            break;
          default:
             break;
        }
    }
}

void performObstacleAvoidance() {
    int distanceR = 0;
    int distanceL =  0;
    delay(40);
   
    if(distance<=15)
    {
      moveStop();
      delay(100);
      moveBackward();
      delay(300);
      moveStop();
      delay(200);
      distanceR = lookRight();
      delay(200);
      distanceL = lookLeft();
      delay(200);
    
      if(distanceR>=distanceL)
      {
        turnRight();
        moveStop();
      }else
      {
        turnLeft();
        moveStop();
      }
    }else
    {
      moveForward();
    }
    distance = readPing();
}

int lookRight()
{
    myservo.write(50); 
    delay(500);
    int distance = readPing();
    delay(100);
    myservo.write(115); 
    return distance;
}

int lookLeft()
{
    myservo.write(170); 
    delay(500);
    int distance = readPing();
    delay(100);
    myservo.write(115); 
    return distance;
    delay(100);
}

int readPing() { 
  delay(70);
  int cm = sonar.ping_cm();
  if(cm==0)
  {
    cm = 250;
  }
  return cm;
}

void moveStop() {
  motor1.run(RELEASE); 
  motor2.run(RELEASE);
  motor3.run(RELEASE);
  motor4.run(RELEASE);
} 

void moveForward() {

 if(!goesForward)
  {
    goesForward=true;
    motor1.run(FORWARD);      
    motor2.run(FORWARD);
    motor3.run(FORWARD); 
    motor4.run(FORWARD);     
   for (speedSet = 0; speedSet < MAX_SPEED; speedSet +=2) // slowly bring the speed up to avoid loading down the batteries too quickly
   {
    motor1.setSpeed(speedSet);
    motor2.setSpeed(speedSet);
    motor3.setSpeed(speedSet);
    motor4.setSpeed(speedSet);
    delay(5);
   }
  }
}

void moveBackward() {
    goesForward=false;
    motor1.run(BACKWARD);      
    motor2.run(BACKWARD);
    motor3.run(BACKWARD);
    motor4.run(BACKWARD);  
  for (speedSet = 0; speedSet < MAX_SPEED; speedSet +=2) // slowly bring the speed up to avoid loading down the batteries too quickly
  {
    motor1.setSpeed(speedSet);
    motor2.setSpeed(speedSet);
    motor3.setSpeed(speedSet);
    motor4.setSpeed(speedSet);
    delay(5);
  }
}  

void turnRight() {
  motor1.run(FORWARD);
  motor2.run(FORWARD);
  motor3.run(BACKWARD);
  motor4.run(BACKWARD);     
  delay(500);
  motor1.run(FORWARD);      
  motor2.run(FORWARD);
  motor3.run(FORWARD);
  motor4.run(FORWARD);      
} 

void turnLeft() {
  motor1.run(BACKWARD);     
  motor2.run(BACKWARD);  
  motor3.run(FORWARD);
  motor4.run(FORWARD);   
  delay(500);
  motor1.run(FORWARD);     
  motor2.run(FORWARD);
  motor3.run(FORWARD);
  motor4.run(FORWARD);
}  

void buz() {
    if (b) {
        digitalWrite(buzzerPin, HIGH); // Activate back buzzer
        delay(100); // Adjust as needed
        digitalWrite(buzzerPin, LOW); // Deactivate back buzzer
        delay(500); // Delay before stopping
        
    } else {}
    
}

void forward(int speed)
{
  motor1.setSpeed(speed);
  motor1.run(FORWARD);
  motor2.setSpeed(speed);
  motor2.run(FORWARD);
  motor3.setSpeed(speed);
  motor3.run(FORWARD);
  motor4.setSpeed(speed);
  motor4.run(FORWARD);
}

void back(int speed)
{
  motor1.setSpeed(speed);
  motor1.run(BACKWARD);
  motor2.setSpeed(speed);
  motor2.run(BACKWARD);
  motor3.setSpeed(speed);
  motor3.run(BACKWARD);
  motor4.setSpeed(speed);
  motor4.run(BACKWARD);
}

void left(int speed)
{
  motor1.setSpeed(speed);
  motor1.run(BACKWARD);
  motor2.setSpeed(speed);
  motor2.run(BACKWARD);
  motor3.setSpeed(speed);
  motor3.run(FORWARD);
  motor4.setSpeed(speed);
  motor4.run(FORWARD);
  
}

void right(int speed)
{
  motor1.setSpeed(speed);
  motor1.run(FORWARD);
  motor2.setSpeed(speed);
  motor2.run(FORWARD);
  motor3.setSpeed(speed);
  motor3.run(BACKWARD);
  motor4.setSpeed(speed);
  motor4.run(BACKWARD);
  
}

// Additional movements
void forwardRight(int speed)
{
  motor1.setSpeed(speed);
  motor1.run(FORWARD);
  motor2.setSpeed(speed);
  motor2.run(FORWARD);
  motor3.setSpeed(speed/3.1);
  motor3.run(FORWARD);
  motor4.setSpeed(speed/3.1);
  motor4.run(FORWARD);
}

void forwardLeft(int speed)
{
  motor1.setSpeed(speed/3.1);
  motor1.run(FORWARD);
  motor2.setSpeed(speed/3.1);
  motor2.run(FORWARD);
  motor3.setSpeed(speed);
  motor3.run(FORWARD);
  motor4.setSpeed(speed);
  motor4.run(FORWARD);
}

void backRight(int speed)
{
  motor1.setSpeed(speed);
  motor1.run(BACKWARD);
  motor2.setSpeed(speed);
  motor2.run(BACKWARD);
  motor3.setSpeed(speed/3.1);
  motor3.run(BACKWARD);
  motor4.setSpeed(speed/3.1);
  motor4.run(BACKWARD);
}

void backLeft(int speed)
{
  motor1.setSpeed(speed/3.1);
  motor1.run(BACKWARD);
  motor2.setSpeed(speed/3.1);
  motor2.run(BACKWARD);
  motor3.setSpeed(speed);
  motor3.run(BACKWARD);
  motor4.setSpeed(speed);
  motor4.run(BACKWARD);
}

void setSpeed(int newSpeed)
{
  speed = newSpeed;
}

void Stop()
{
  motor1.setSpeed(0);
  motor1.run(RELEASE);
  motor2.setSpeed(0);
  motor2.run(RELEASE);
  motor3.setSpeed(0);
  motor3.run(RELEASE);
  motor4.setSpeed(0);
  motor4.run(RELEASE);
}

void StopAll()
{
  Stop();
 }

Connections:
Ultrasonic:
Echo to A1
Trig to A0
GND to GND
VCC to 5v

Servo:
Signal to 10
Gnd to Gnd
Vcc to 5v

Hc-05:
State to A5
Gnd to Gnd
Vcc to 5v
RxD to None
TxD to 9

On the obstacle avoiding mode, it just goes straight. When I tried the code without the bluetooth things, it worked perfectly, bluetooth control also works fine but when disconnected just stays on bluetooth. Thanks!

2

could it be the pin being used to select the mode?

buttons are typically connected between the pin and ground, the pin configured as INPUT_PULLUP to use the internal pullup resistor which pulls the pin HIGH and when pressed, the button pulls the pin LOW.

a button press can be recognized by detecting a change in state and becoming LOW

3

The state pins connected to the state of the bluetooth hc05. It works fine. But I think the problem is the code.

4

aren't you using STATE_PIN to determine the mode?

5

Yep, since hc05 module sends HIGH to determine that it has been connected

7

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