Arnov Sharma
Published © GPL3+

Yet another Arduino self balancing robot

Made a Self Balancing Robot with 3D Printed parts and MPU6050

BeginnerFull instructions provided6 hours2,613

Things used in this project

Hardware components

Arduino Nano R3
Arduino Nano R3
×1
SparkFun Triple Axis Accelerometer and Gyro Breakout - MPU-6050
SparkFun Triple Axis Accelerometer and Gyro Breakout - MPU-6050
×1
SparkFun Full-Bridge Motor Driver Breakout - L298N
SparkFun Full-Bridge Motor Driver Breakout - L298N
×1
JLCPCB Customized PCB
JLCPCB Customized PCB
×1

Software apps and online services

Fusion 360
Autodesk Fusion 360

Hand tools and fabrication machines

3D Printer (generic)
3D Printer (generic)

Story

Read more

Custom parts and enclosures

Base

Battery Holder

Bottom

Bush

Upper Level

Fusion360FIle

Schematics

sch

Code

code

C/C++
#include <PID_v1.h>
#include <LMotorController.h>
#include "I2Cdev.h"
#include "MPU6050_6Axis_MotionApps20.h"

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

#define MIN_ABS_SPEED 30

MPU6050 mpu;

// 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
VectorFloat gravity; // [x, y, z] gravity vector
float ypr[3]; // [yaw, pitch, roll] yaw/pitch/roll container and gravity vector

//PID
double originalSetpoint = 173;
double setpoint = originalSetpoint;
double movingAngleOffset = 0.1;
double input, output;

//adjust these values to fit your own design
double Kp = 60;   //too little KP will make robot fall 
double Kd = 3; //to decrease the oscillation
double Ki = 270;
PID pid(&input, &output, &setpoint, Kp, Ki, Kd, DIRECT);

double motorSpeedFactorLeft = 0.5;
double motorSpeedFactorRight = 0.5;

//MOTOR CONTROLLER
int ENA = 5;
int IN1 = 10;
int IN2 = 11;
int IN3 = 6;
int IN4 = 9;
int ENB = 3;
LMotorController motorController(ENA, IN1, IN2, ENB, IN3, IN4, motorSpeedFactorLeft, motorSpeedFactorRight);

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


void setup()
{
 // 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

 mpu.initialize();

 devStatus = mpu.dmpInitialize();

 // supply your own gyro offsets here, scaled for min sensitivity
 mpu.setXGyroOffset(220);
 mpu.setYGyroOffset(76);
 mpu.setZGyroOffset(-85);
 mpu.setZAccelOffset(1788); // 1688 factory default for my test chip

 // make sure it worked (returns 0 if so)
 if (devStatus == 0)
 {
 // turn on the DMP, now that it's ready
 mpu.setDMPEnabled(true);

 // enable Arduino interrupt detection
 attachInterrupt(0, dmpDataReady, RISING);
 mpuIntStatus = mpu.getIntStatus();

 // set our DMP Ready flag so the main loop() function knows it's okay to use it
 dmpReady = true;

 // get expected DMP packet size for later comparison
 packetSize = mpu.dmpGetFIFOPacketSize();
 
 //setup PID
 pid.SetMode(AUTOMATIC);
 pid.SetSampleTime(10);
 pid.SetOutputLimits(-255, 255); 
 }
 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(")"));
 }
}


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)
 {
 //no mpu data - performing PID calculations and output to motors 
 pid.Compute();
 motorController.move(output, MIN_ABS_SPEED);
 
 }

 // 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;

 mpu.dmpGetQuaternion(&q, fifoBuffer);
 mpu.dmpGetGravity(&gravity, &q);
 mpu.dmpGetYawPitchRoll(ypr, &q, &gravity);
 input = ypr[1] * 180/M_PI + 180;
 }
}

Credits

Arnov Sharma

Arnov Sharma

273 projects • 283 followers
Just your average MAKER

Comments

Related channels and tags
  • 3D Printing
  • Arduino
  • Autodesk
  • Robotics
  • SparkFun
  • TDK Corporation