How to merge 2 program into 1 and work it together?

Like the title...when I merge the self-balancing code with the line following code, it only works line following function only.

line_following.ino (1.38 KB)

balancing.ino (4.22 KB)

balancing + line following.txt (5.53 KB)

You should post your code inline, like this...

#include <PID_v1.h>
#include <LMotorController.h>
#include "I2Cdev.h"
#include "MPU6050_6Axis_MotionApps20.h"

#include "Wire.h"

#define MIN_ABS_SPEED 30

int Sensor2 = 0;
int Sensor3 = 0;
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

double originalSetpoint = 172.50;
double setpoint = originalSetpoint;
double movingAngleOffset = 0.1;
double input, output;

//adjust these values to fit your own design
double Kp = 60;
double Kd = 2.2;
double Ki = 270;
PID pid(&input, &output, &setpoint, Kp, Ki, Kd, DIRECT);

double motorSpeedFactorLeft = 0.6;
double motorSpeedFactorRight = 0.5;

int ENA = 5;
int IN1 = 6;
int IN2 = 7;
int IN3 = 9;
int IN4 = 8;
int ENB = 10;
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()
  pinMode(ENA, OUTPUT);
  pinMode(IN2, OUTPUT);

  pinMode(ENB, OUTPUT);
  pinMode(IN3, OUTPUT);

  pinMode(Sensor2, INPUT);
  pinMode(Sensor3, INPUT);
  // join I2C bus (I2Cdev library doesn't do this automatically)
  TWBR = 24; // 400kHz I2C clock (200kHz if CPU is 8MHz)
  Fastwire::setup(400, true);


  devStatus = mpu.dmpInitialize();

  // supply your own gyro offsets here, scaled for min sensitivity
  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

    // 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.SetOutputLimits(-255, 255);
    // 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 "));


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
    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
    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;

    //Use analogWrite to run motor at adjusted speed
    analogWrite(ENA, MIN_ABS_SPEED);
    analogWrite(ENB, MIN_ABS_SPEED);

    //Read the Sensor if HIGH (BLACK Line) or LOW (WHITE Line)
    Sensor2 = digitalRead(3);
    Sensor3 = digitalRead(4);

    //Set conditions for FORWARD, LEFT and RIGHT

    if (Sensor3 == HIGH && Sensor2 == LOW)

      //Turn LEFT
      //motor A Backward
      digitalWrite(IN1, LOW);
      digitalWrite(IN2, HIGH);

      //motor B Forward
      digitalWrite(IN3, HIGH);
      digitalWrite(IN4, LOW);

    else if (Sensor3 == LOW && Sensor2 == HIGH)

      //Turn RIGHT
      //motor A Forward
      digitalWrite(IN1, HIGH);
      digitalWrite(IN2, LOW);

      //motor B Backward
      digitalWrite(IN3, LOW);
      digitalWrite(IN4, HIGH);

    else {

      //if(Sensor3 == HIGH && Sensor2 == HIGH)

      digitalWrite(IN1, LOW);
      digitalWrite(IN2, HIGH);
      digitalWrite(IN3, LOW);
      digitalWrite(IN4, HIGH);

As you have no doubt worked out, the Arduino IDE doesn't like spaces in the file names. Your second file cannot even be opened without changing the name.

So, on to the real problems. You have some kind of motors attached to pins IN1, IN2 etc. Your PID balancing code uses the motor controller object's high level functions like .move() to move the motors.

Then the line-following part of the code just does a digitalWrite(IN1, HIGH). How is that going to help the motor controller control the motor with the fine precision that the PID requires?

Think about this another way: You have it balancing OK, right? Well how about just applying a little lean to make it go the way you want it to? Build upon the core balancing sketch slowly - first try to make it go forwards and backwards under your control.

This Simple Merge Demo may give you some ideas.


[merge sketch code program site:](http://merge sketch code program site: