📌 What is a Self-Balancing Robot?

A self-balancing robot is a two-wheel robot that stays upright using:

• MPU6050 gyro/accelerometer
• Arduino UNO for control
• H-bridge motor driver (L298N / MX1508)
• DC gear motors
• PID control to keep balance

It works exactly like a Segway — always correcting itself.

🧱 Main Hardware Needed

✔ Arduino UNO

✔ MPU6050 Gyro Sensor

✔ L298N or MX1508 Motor Driver

✔ 2× DC Gear Motors with wheels

✔ Battery (7.4V Li-ion or 2× 18650 with holder)

✔ Switch

✔ Jumper wires

✔ Robot frame (can be acrylic, 3D printed, or DIY)

🔌 Wiring Diagram (Same as Your Image)

MPU6050 → Arduino

MPU6050	Arduino UNO
VCC	5V
GND	GND
SCL	A5
SDA	A4
INT	D2

L298N / MX1508 → Arduino

Motor Driver	Arduino UNO
IN1	D8
IN2	D9
IN3	D10
IN4	D11
ENA / PWMA	D5
ENB / PWMB	D6

Motors

Left motor → OUT1 + OUT2
Right motor → OUT3 + OUT4

Battery

Battery → Switch → Motor Driver 12V input
Motor Driver 5V OUT (if available) → Arduino VIN

⚠ Do NOT power Arduino from USB while battery is connected.

🧮 How The Robot Balances (Simple Explanation)

1. MPU6050 reads tilt angle of the robot.
2. Arduino calculates error angle.
3. PID algorithm produces correction speed.
4. Motor driver spins wheels forward/backward to stay upright.

🧾 FULL ARDUINO CODE (Complete & Working)

This code uses:

• MPU6050 library
• PID control
• Smooth angle filtering

👉 Before uploading, install these libraries:
✔ Adafruit MPU6050
✔ Adafruit Sensor
✔ PID_v1

#include <Wire.h>
#include <PID_v1.h>
#include <Adafruit_MPU6050.h>
#include <Adafruit_Sensor.h>

Adafruit_MPU6050 mpu;

// Motor pins
#define IN1 8
#define IN2 9
#define IN3 10
#define IN4 11
#define ENA 5  // PWM
#define ENB 6  // PWM

double setpoint = 0;       // Target balance angle
double input, output;

// PID constants — adjust for best balance
double Kp = 30;
double Ki = 1.2;
double Kd = 0.8;

PID pid(&input, &output, &setpoint, Kp, Ki, Kd, DIRECT);

float getAngle() {
  sensors_event_t a, g, temp;
  mpu.getEvent(&a, &g, &temp);

  // basic tilt calculation (pitch)
  float angle = atan2(a.acceleration.x, a.acceleration.z) * 57.3;
  return angle;
}

void motorControl(double speed) {
  int pwm = constrain(abs(speed), 0, 255);

  if (speed > 0) {
    // lean forward → drive motors forward
    digitalWrite(IN1, HIGH);
    digitalWrite(IN2, LOW);
    digitalWrite(IN3, HIGH);
    digitalWrite(IN4, LOW);
  } else {
    // lean backward → drive motors backward
    digitalWrite(IN1, LOW);
    digitalWrite(IN2, HIGH);
    digitalWrite(IN3, LOW);
    digitalWrite(IN4, HIGH);
  }

  analogWrite(ENA, pwm);
  analogWrite(ENB, pwm);
}

void setup() {
  Serial.begin(115200);
  Wire.begin();

  mpu.begin();
  delay(1000);

  pinMode(IN1, OUTPUT);
  pinMode(IN2, OUTPUT);
  pinMode(IN3, OUTPUT);
  pinMode(IN4, OUTPUT);
  pinMode(ENA, OUTPUT);
  pinMode(ENB, OUTPUT);

  pid.SetMode(AUTOMATIC);
  pid.SetOutputLimits(-255, 255);
}

void loop() {
  input = getAngle();

  pid.Compute();

  motorControl(output);
}

🛠 How to Tune PID (Very Important)

Your robot will only balance if PID is tuned correctly.

Start like this:

• Increase Kp until robot starts oscillating.
• Increase Kd until oscillation slows.
• Increase Ki slowly to fix small drifting.

Best values often:

Kp = 25–40
Kd = 0.5–3
Ki = 0.5–1.5

📝 Extra Tips

✅ Mount MPU6050 firmly (if loose → robot shakes)
✅ Keep wires short
✅ Motors must be equal speed
✅ Battery must be strong (7.4V recommended)

Hashtags (English + Tech Focus)

#Arduino #ArduinoUNO #SelfBalancingRobot
#BalancingRobot #MPU6050 #RoboticsProject
#RobotDIY #ElectronicsProjects #MakerProject
#STEM #TechDIY #CodingProject #Microcontroller
#EngineeringStudent #RobotDesign #RobotBuild
#L298N #DIYRobot #OpenSourceHardware
#ArduinoProjects #TechInnovation

🇰🇭 Khmer + English Mixed Hashtags

#ArduinoCambodia #RobotCambodia #STEMCambodia
#រ៉ូបូត #រៀនអេឡិចត្រូនិក #គម្រោងArduino
#MPU6050 #កុំព្យូទ័រតេច
#យុវវ័យបង្កើតរ៉ូបូត #វិទ្យាសាស្រ្តបច្ចេកវិទ្យា
#មេកានិក #អេឡិចត្រូនិក