Arduino two weel self Balancing Robot

1#include "I2Cdev.h"
2#include <PID_v1.h> //From https://github.com/br3ttb/Arduino-PID-Library/blob/master/PID_v1.h
3#include "MPU6050_6Axis_MotionApps20.h" //https://github.com/jrowberg/i2cdevlib/tree/master/Arduino/MPU6050
4MPU6050 mpu;
5// MPU control/status vars
6bool dmpReady = false;  // set true if DMP init was successful
7uint8_t mpuIntStatus;   // holds actual interrupt status byte from MPU
8uint8_t devStatus;      // return status after each device operation (0 = success, !0 = error)
9uint16_t packetSize;    // expected DMP packet size (default is 42 bytes)
10uint16_t fifoCount;     // count of all bytes currently in FIFO
11uint8_t fifoBuffer[64]; // FIFO storage buffer
12// orientation/motion vars
13Quaternion q;           // [w, x, y, z]         quaternion container
14VectorFloat gravity;    // [x, y, z]            gravity vector
15float ypr[3];           // [yaw, pitch, roll]   yaw/pitch/roll container and gravity vector
16/*********Tune these 4 values for your BOT*********/
17double setpoint= 182; //set the value when the bot is perpendicular to ground using serial monitor. 
18//Read the project documentation on circuitdigest.com to learn how to set these values
19double Kp = 15; //21 Set this first
20double Kd = 0.9; //0.8 Set this secound
21double Ki = 140; //140 Finally set this 
22/******End of values setting*********/
23double input, output;
24PID pid(&input, &output, &setpoint, Kp, Ki, Kd, DIRECT);
25volatile bool mpuInterrupt = false;     // indicates whether MPU interrupt pin has gone high
26void dmpDataReady()
27{
28    mpuInterrupt = true;
29}
30void setup() {
31  Serial.begin(115200);
32  // initialize device
33    Serial.println(F("Initializing I2C devices..."));
34    mpu.initialize();
35     // verify connection
36    Serial.println(F("Testing device connections..."));
37    Serial.println(mpu.testConnection() ? F("MPU6050 connection successful") : F("MPU6050 connection failed"));
38    // load and configure the DMP
39    devStatus = mpu.dmpInitialize();
40    // supply your own gyro offsets here, scaled for min sensitivity
41    mpu.setXGyroOffset(-479);
42    mpu.setYGyroOffset(84);
43    mpu.setZGyroOffset(15);
44    mpu.setZAccelOffset(1638); 
45      // make sure it worked (returns 0 if so)
46    if (devStatus == 0)
47    {
48        // turn on the DMP, now that it's ready
49        Serial.println(F("Enabling DMP..."));
50        mpu.setDMPEnabled(true);
51        // enable Arduino interrupt detection
52        Serial.println(F("Enabling interrupt detection (Arduino external interrupt 0)..."));
53        attachInterrupt(0, dmpDataReady, RISING);
54        mpuIntStatus = mpu.getIntStatus();
55        // set our DMP Ready flag so the main loop() function knows it's okay to use it
56        Serial.println(F("DMP ready! Waiting for first interrupt..."));
57        dmpReady = true;
58        // get expected DMP packet size for later comparison
59        packetSize = mpu.dmpGetFIFOPacketSize();
60        //setup PID
61        pid.SetMode(AUTOMATIC);
62        pid.SetSampleTime(10);
63        pid.SetOutputLimits(-255, 255);
64    }
65    else
66    {
67        // ERROR!
68        // 1 = initial memory load failed
69        // 2 = DMP configuration updates failed
70        // (if it's going to break, usually the code will be 1)
71        Serial.print(F("DMP Initialization failed (code "));
72        Serial.print(devStatus);
73        Serial.println(F(")"));
74    }
75//Initialise the Motor outpu pins
76    pinMode (6, OUTPUT);
77    pinMode (9, OUTPUT);
78    pinMode (10, OUTPUT);
79    pinMode (11, OUTPUT);
80//By default turn off both the motors
81    analogWrite(6,LOW);
82    analogWrite(9,LOW);
83    analogWrite(10,LOW);
84    analogWrite(11,LOW);
85}
86void loop() {
87    // if programming failed, don't try to do anything
88    if (!dmpReady) return;
89    // wait for MPU interrupt or extra packet(s) available
90    while (!mpuInterrupt && fifoCount < packetSize)
91    {
92        //no mpu data - performing PID calculations and output to motors     
93        pid.Compute();
94        //Print the value of Input and Output on serial monitor to check how it is working.
95        Serial.print(input); Serial.print(" =>"); Serial.println(output);
96        if (input>150 && input<200){//If the Bot is falling 
97        if (output>0) //Falling towards front 
98        Forward(); //Rotate the wheels forward 
99        else if (output<0) //Falling towards back
100        Reverse(); //Rotate the wheels backward 
101        }
102        else //If Bot not falling
103        Stop(); //Hold the wheels still
104    }
105    // reset interrupt flag and get INT_STATUS byte
106    mpuInterrupt = false;
107    mpuIntStatus = mpu.getIntStatus();
108    // get current FIFO count
109    fifoCount = mpu.getFIFOCount();
110    // check for overflow (this should never happen unless our code is too inefficient)
111    if ((mpuIntStatus & 0x10) || fifoCount == 1024)
112    {
113        // reset so we can continue cleanly
114        mpu.resetFIFO();
115        Serial.println(F("FIFO overflow!"));
116    // otherwise, check for DMP data ready interrupt (this should happen frequently)
117    }
118    else if (mpuIntStatus & 0x02)
119    {
120        // wait for correct available data length, should be a VERY short wait
121        while (fifoCount < packetSize) fifoCount = mpu.getFIFOCount();
122        // read a packet from FIFO
123        mpu.getFIFOBytes(fifoBuffer, packetSize);
124        // track FIFO count here in case there is > 1 packet available
125        // (this lets us immediately read more without waiting for an interrupt)
126        fifoCount -= packetSize;
127        mpu.dmpGetQuaternion(&q, fifoBuffer); //get value for q
128        mpu.dmpGetGravity(&gravity, &q); //get value for gravity
129        mpu.dmpGetYawPitchRoll(ypr, &q, &gravity); //get value for ypr
130        input = ypr[1] * 180/M_PI + 180;
131   }
132}
133void Forward() //Code to rotate the wheel forward 
134{
135    analogWrite(6,output);
136    analogWrite(9,0);
137    analogWrite(10,output);
138    analogWrite(11,0);
139    Serial.print("F"); //Debugging information 
140}
141void Reverse() //Code to rotate the wheel Backward  
142{
143    analogWrite(6,0);
144    analogWrite(9,output*-1);
145    analogWrite(10,0);
146    analogWrite(11,output*-1);
147    Serial.print("R");
148}
149void Stop() //Code to stop both the wheels
150{
151    analogWrite(6,0);
152    analogWrite(9,0);
153    analogWrite(10,0);
154    analogWrite(11,0);
155    Serial.print("S");
156}