self balance robot arduino

 A self-balancing robot using Arduino typically works on the principle of an inverted pendulum. It uses sensors like an MPU6050 (gyro + accelerometer) to detect the angle of tilt and adjusts motors to balance itself.

Components:

1. Arduino Uno/Nano

2. MPU6050 (Gyro + Accelerometer)

3. 2 DC Motors with Encoders (or without, but better with)

4. Motor Driver (L298N or L9110S)

5. Wheels + Chassis

6. Battery Pack (Li-ion or LiPo)

7. Optional: Bluetooth module (HC-05) for control

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Wiring

• MPU6050

  • VCC → 5V

  • GND → GND

  • SDA → A4 (on Uno)

  • SCL → A5

• Motor Driver

  • IN1, IN2 → Arduino digital pins (e.g., D8, D9)

  • IN3, IN4 → Arduino digital pins (e.g., D10, D11)

  • ENA/ENB (speed control) → PWM pins (e.g., D5, D6)

  • Motor outputs → DC motors

  • VCC → Motor power (e.g., 7.4V LiPo)

  • GND → Common ground

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Arduino Code

#include <Wire.h>
#include <MPU6050.h>

MPU6050 mpu;

float Kp = 20, Ki = 0.5, Kd = 1.2;
float setPoint = 0;
float input, output, error, previous_error = 0, integral = 0;

int motor1Pin1 = 8, motor1Pin2 = 9;
int motor2Pin1 = 10, motor2Pin2 = 11;
int pwmA = 5, pwmB = 6;

void setup() {
  Serial.begin(9600);
  Wire.begin();
  mpu.initialize();

  pinMode(motor1Pin1, OUTPUT);
  pinMode(motor1Pin2, OUTPUT);
  pinMode(motor2Pin1, OUTPUT);
  pinMode(motor2Pin2, OUTPUT);
  pinMode(pwmA, OUTPUT);
  pinMode(pwmB, OUTPUT);
}

void loop() {
  int16_t ax, ay, az, gx, gy, gz;
  mpu.getMotion6(&ax, &ay, &az, &gx, &gy, &gz);

  input = atan2(ay, az) * 180 / PI;

  error = setPoint - input;
  integral += error;
  float derivative = error - previous_error;

  output = Kp * error + Ki * integral + Kd * derivative;
  previous_error = error;

  setMotorSpeed(output);
}

void setMotorSpeed(float speed) {
  int motorSpeed = min(abs(speed), 255);

  if (speed > 0) {
    digitalWrite(motor1Pin1, HIGH);
    digitalWrite(motor1Pin2, LOW);
    digitalWrite(motor2Pin1, HIGH);
    digitalWrite(motor2Pin2, LOW);
  } else {
    digitalWrite(motor1Pin1, LOW);
    digitalWrite(motor1Pin2, HIGH);
    digitalWrite(motor2Pin1, LOW);
    digitalWrite(motor2Pin2, HIGH);
  }

  analogWrite(pwmA, motorSpeed);
  analogWrite(pwmB, motorSpeed);
}