Self Balancing Robot ArduinoUno/mpu6050/l298n

Hello,
The robot is moving very fast. it only moves forward. How can I fix?


#include "I2Cdev.h"

#include "MPU6050_6Axis_MotionApps20.h"

#if I2CDEV_IMPLEMENTATION == I2CDEV_ARDUINO_WIRE
    #include "Wire.h"
#endif


MPU6050 mpu;

#define OUTPUT_READABLE_YAWPITCHROLL

#define LED_PIN 13 
bool blinkState = false;

// MPU control/status vars
bool dmpReady = false;  // set true if DMP init was successful
uint8_t mpuIntStatus;   // holds actual interrupt status byte from MPU
uint8_t devStatus;      // return status after each device operation (0 = success, !0 = error)
uint16_t packetSize;    // expected DMP packet size (default is 42 bytes)
uint16_t fifoCount;     // count of all bytes currently in FIFO
uint8_t fifoBuffer[64]; // FIFO storage buffer

// orientation/motion vars
Quaternion q;           // [w, x, y, z]         quaternion container
VectorInt16 aa;         // [x, y, z]            accel sensor measurements
VectorInt16 aaReal;     // [x, y, z]            gravity-free accel sensor measurements
VectorInt16 aaWorld;    // [x, y, z]            world-frame accel sensor measurements
VectorFloat gravity;    // [x, y, z]            gravity vector
float euler[3];         // [psi, theta, phi]    Euler angle container
float ypr[3];           // [yaw, pitch, roll]   yaw/pitch/roll container and gravity vector

// packet structure for InvenSense teapot demo
uint8_t teapotPacket[14] = { '$', 0x02, 0,0, 0,0, 0,0, 0,0, 0x00, 0x00, '\r', '\n' };
//*************************************************************************************************************************************************************************
//                                                 Variables

float OldP = 0;         // Previous value used to calculate change in P //  DELTA P
float P = 0;            //  Proportional component
float I = 0;            //  Integral        just the sum of P over time
float OldI = 0;         //  previous value of I for calculation of Delta I
float D = 0;            //  Differential       D = P - OldP
float bp = -60;         // balance point
float pwm = 0;          // value of Pulse Width Modulation  to ENA ENB
long a = 0;             // L298N to IN 1 to 4
long b = 0;             //
const int PinR1 = 9;    //  arduino  pin 5 to l298  pin IN4
const int PinR2 = 8;    //  arduino  pin 6 to l298  pin IN3
const int PinL1 = 6;    //  arduino  pin 7 to l298  pin IN1
const int PinL2 = 7;    //  arduino  pin 8 to l298  pin IN2
const int PwmR  = 10;    //  arduino  pin 9 to l298  pin ENB
const int PwmL  = 5;   //  arduino  pin 10 to l298  pin ENA
//****************************************************************************************************************************************************


// ================================================================
// ===               INTERRUPT DETECTION ROUTINE                ===
// ================================================================

volatile bool mpuInterrupt = false;     // indicates whether MPU interrupt pin has gone high
void dmpDataReady() {
    mpuInterrupt = true;
}



// ================================================================
// ===                      INITIAL SETUP                       ===
// ================================================================

void setup() {
//*********************************************************************************************************************************************************
// arduino to l298 pins hopefully self explanatory
      pinMode(PinR1,OUTPUT);
      pinMode(PinR2,OUTPUT);
      pinMode(PinL1,OUTPUT);
      pinMode(PinL2,OUTPUT);
//**********************************************************************************************************************************************************
    // join I2C bus (I2Cdev library doesn't do this automatically)
    #if I2CDEV_IMPLEMENTATION == I2CDEV_ARDUINO_WIRE
        Wire.begin();
        TWBR = 24; // 400kHz I2C clock (200kHz if CPU is 8MHz)
    #elif I2CDEV_IMPLEMENTATION == I2CDEV_BUILTIN_FASTWIRE
        Fastwire::setup(400, true);
    #endif

    // initialize serial communication
    Serial.begin(57600);
    while (!Serial); // 

    // initialize device
    Serial.println(F("Initializing I2C devices..."));
    mpu.initialize();

    // verify connection
    Serial.println(F("Testing device connections..."));
    Serial.println(mpu.testConnection() ? F("MPU6050 connection successful") : F("MPU6050 connection failed"));


// load and configure the DMP
    Serial.println(F("Initializing DMP..."));
    devStatus = mpu.dmpInitialize();

    // supply your own gyro offsets here, scaled for min sensitivity
 //****************************************************************************************************************************************
 //  use calibration program to get your own values
    mpu.setXGyroOffset(44);//(220);
    mpu.setYGyroOffset(-21);//(76);
    mpu.setZGyroOffset(-30);//(-85);
    mpu.setXAccelOffset(-1875);//(1788); // 1688 factory default for my test chip
    mpu.setYAccelOffset(-1426);
    mpu.setZAccelOffset(2215);
 //****************************************************************************************************************************************
    // make sure it worked (returns 0 if so)
    if (devStatus == 0) {
        // turn on the DMP, now that it's ready
        Serial.println(F("Enabling DMP..."));
        mpu.setDMPEnabled(true);

        // enable Arduino interrupt detection
        Serial.println(F("Enabling interrupt detection (Arduino external interrupt 0)..."));
        attachInterrupt(0, dmpDataReady, RISING);
        mpuIntStatus = mpu.getIntStatus();

        // set our DMP Ready flag so the main loop() function knows it's okay to use it
        Serial.println(F("DMP ready! Waiting for first interrupt..."));
        dmpReady = true;

        // get expected DMP packet size for later comparison
        packetSize = mpu.dmpGetFIFOPacketSize();
    } else {
        // ERROR!
        // 1 = initial memory load failed
        // 2 = DMP configuration updates failed
        // (if it's going to break, usually the code will be 1)
        Serial.print(F("DMP Initialization failed (code "));
        Serial.print(devStatus);
        Serial.println(F(")"));
    }

    // configure LED for output
    pinMode(LED_PIN, OUTPUT);

}



// ================================================================
// ===                    MAIN PROGRAM LOOP                     ===
// ================================================================

void loop() {
    // if programming failed, don't try to do anything
    if (!dmpReady) return;

    // wait for MPU interrupt or extra packet(s) available
    while (!mpuInterrupt && fifoCount < packetSize) {
        // other program behavior stuff here
   
               
     }

    // reset interrupt flag and get INT_STATUS byte
    mpuInterrupt = false;
    mpuIntStatus = mpu.getIntStatus();

    // get current FIFO count
    fifoCount = mpu.getFIFOCount();

    // check for overflow (this should never happen unless our code is too inefficient)
    if ((mpuIntStatus & 0x10) || fifoCount == 1024) {
        // reset so we can continue cleanly
        mpu.resetFIFO();
        Serial.println(F("FIFO overflow!"));

    // otherwise, check for DMP data ready interrupt (this should happen frequently)
    } else if (mpuIntStatus & 0x02) {
        // wait for correct available data length, should be a VERY short wait
        while (fifoCount < packetSize) fifoCount = mpu.getFIFOCount();

        // read a packet from FIFO
        mpu.getFIFOBytes(fifoBuffer, packetSize);
       
        // track FIFO count here in case there is > 1 packet available
        // (this lets us immediately read more without waiting for an interrupt)
        fifoCount -= packetSize;

        #ifdef OUTPUT_READABLE_YAWPITCHROLL      
          // display Euler angles in degrees
          mpu.dmpGetQuaternion(&q, fifoBuffer);
          mpu.dmpGetGravity(&gravity, &q);
          mpu.dmpGetYawPitchRoll(ypr, &q, &gravity);
         
   
//*********************************************************************************************************************************************************************
//                                                                    
// PID control based on Pseudocode from https://en.wikipedia.org/wiki/PID_controller
// and the balance point idea from https://www.youtube.com/user/jmhrvy1947

          OldP =P;                     // save value of P
          P = (ypr[2] * 1000) + bp;    // update P from MPU add bp to correct for balance
          OldI = I;                    // save old I
          I = I + (P * 0.05) ;        
          I = I + ((I - OldI)*2  );     // calulate new I
          if( I >  250 ) I =  250;           // LIMIT  Stop I building up too high
          if( I < -250 ) I = -250;           // or too low value
          D = P - OldP;                      //  D differential   change in P
          pwm = ( P * 1 ) + ( I  ) + ( D * 10 ) ; // P I D  
         
          a = 0;
          b = 0;
          if(pwm < 0){    
            a = 0;
            b = 1;
             bp = bp - 0.01;      
            digitalWrite(13, 0);
          }
          if(pwm > 0){    
            a = 1;
            b = 0;
            bp = bp + 0.01;          
            digitalWrite(13, 1);                                  
          }
          /////////////////////////////
          // remove sign from PWM as - value has no meaning        
          pwm  = abs(pwm);                  
          if ( pwm < 0) pwm = 0;
          if ( pwm > 255) pwm = 255;

            if(abs(ypr[2]) < abs(1.1)){
              analogWrite(PwmR, pwm);
              digitalWrite(PinR1, a);
              digitalWrite(PinR2 ,b);
             
              analogWrite(PwmL ,pwm);
              digitalWrite(PinL1 ,a);
              digitalWrite(PinL2 ,b);
              }
           else{
              analogWrite(PwmR , 0);
              analogWrite(PwmL , 0);
              I = 0;
              bp = -98;
              delay(1000);
           }
         
 //********************************************************************************************************************************************************          
        #endif        
    }
}

To be as short in my answer as you are short in describing your project:

"adjust the PID-parameters"

Does this help? I Guess not.

a self-balancing robot is a pretty demanding project.
You need at least to know something about strategies how to
adjust PID-parameters.

You should know something about the relations between the mechanical size and what certain ways of how the weight is distrubuted on the robot has what effects on forces and accelleration.

Not in a way that you have to do complex calculations but to know what in principle changes if you move the center of gravity more towards the wheels or away from the wheels.

best regards Stefan

how are you controlling the robot? i don't see what the input device is

I did calibration for gy521. I added the resulting values ​​to the code.

I made a single supply with a 9v battery. Does this have negative effects?

https://www.instructables.com/Balance-Bot-ArduinoUnompu6050l298n/

I am implementing the project on this web page.

using such a battery

for arduino and motor is
is insufficient.
even small motors need a

bigger battery

there is a reason why the picture on instructables has this battery-case

AA-batteries. Especially NiMH accumulators deliver a much higher current than such a 9V block.

best regards Stefan