MinIMU9AHRS.ino: In function 'void setup()':
MinIMU9AHRS:158: error: 'I2C_Init' was not declared in this scope
MinIMU9AHRS:165: error: 'Accel_Init' was not declared in this scope
MinIMU9AHRS:166: error: 'Compass_Init' was not declared in this scope
MinIMU9AHRS:167: error: 'Gyro_Init' was not declared in this scope
MinIMU9AHRS:173: error: 'Read_Gyro' was not declared in this scope
MinIMU9AHRS:174: error: 'Read_Accel' was not declared in this scope
MinIMU9AHRS.ino: In function 'void loop()':
MinIMU9AHRS:211: error: 'Read_Gyro' was not declared in this scope
MinIMU9AHRS:212: error: 'Read_Accel' was not declared in this scope
MinIMU9AHRS:217: error: 'Read_Compass' was not declared in this scope

#include <LPS.h>
#include <LSM303.h>
#include <Wire.h>

LSM303 compass;


 void setup(){
  setupmagnetometer();
  setupattitude();
  setupaltitude();
}

  void loop(){
  loopmagnetometer();
  loopattitude();
  loopaltitude();
}

 void setupmagnetometer(){

  Serial.begin(9600);
  Wire.begin();
  compass.init();
  compass.enableDefault();

  /*
   Calibration values; the default values of +/-32767 for each axis
  lead to an assumed magnetometer bias of 0. Use the Calibrate example
  program to determine appropriate values for your particular unit.
  */
  compass.m_min = (LSM303::vector<int16_t>){-32767, -32767, -32767};
  compass.m_max = (LSM303::vector<int16_t>){+32767, +32767, +32767};
  }

void loopmagnetometer(){

compass.read();

 /*
 When given no arguments, the heading() function returns the angular
 difference in the horizontal plane between a default vector and
 north, in degrees.

  The default vector is chosen by the library to point along the
  surface of the PCB, in the direction of the top of the text on the
  silkscreen. This is the +X axis on the Pololu LSM303D carrier and
  the -Y axis on the Pololu LSM303DLHC, LSM303DLM, and LSM303DLH
  carriers.

  To use a different vector as a reference, use the version of heading()
  that takes a vector argument; for example, use

 compass.heading((LSM303::vector<int>){0, 0, 1});

 to use the +Z axis as a reference.
  */
  float heading = compass.heading();


Serial.print(heading);
Serial.println(" deg");

delay(1000);
} 

LPS ps;

void setupaltitude()
{
  Serial.begin(9600);
  Wire.begin();

  if (!ps.init())
{
    Serial.println("Failed to autodetect pressure sensor!");
    while (1);
}

  ps.enableDefault();
}
  void loopaltitude()
{ 
  float pressure = ps.readPressureMillibars();
  float altitude = ps.pressureToAltitudeMeters(pressure);
  float temperature = ps.readTemperatureC();

  Serial.print("Pressure: ");
  Serial.print(pressure);
  Serial.print(" mbar\tAltitude: ");
  Serial.print(altitude);
  Serial.print(" m\tTemperature: ");
  Serial.print(temperature);
  Serial.println(" deg C");

  delay(1000);
}
 // Uncomment the below line to use this axis definition: 
 // X axis pointing forward
 // Y axis pointing to the right 
 // and Z axis pointing down.
// Positive pitch : nose up
// Positive roll : right wing down
// Positive yaw : clockwise
int SENSOR_SIGN[9] = {1,1,1,-1,-1,-1,1,1,1}; //Correct directions x,y,z -gyro,accelerometer, magnetometer
// Uncomment the below line to use this axis definition: 
// X axis pointing forward
// Y axis pointing to the left 
// and Z axis pointing up.
// Positive pitch : nose down
// Positive roll : right wing down
// Positive yaw : counterclockwise
//int SENSOR_SIGN[9] = {1,-1,-1,-1,1,1,1,-1,-1}; //Correct directions x,y,z - gyro,    accelerometer, magnetometer

// tested with Arduino Uno with ATmega328 and Arduino Duemilanove with ATMega168

// LSM303 accelerometer: 8 g sensitivity
  // 3.9 mg/digit; 1 g = 256
#define GRAVITY 256  //this equivalent to 1G in the raw data coming from the accelerometer 

 #define ToRad(x) ((x)*0.01745329252)  // *pi/180
 #define ToDeg(x) ((x)*57.2957795131)  // *180/pi

// L3G4200D gyro: 2000 dps full scale

// LSM303 magnetometer calibration constants; use the Calibrate example from
// the Pololu LSM303 library to find the right values for your board
#define M_X_MIN -421
#define M_Y_MIN -639
#define M_Z_MIN -238
#define M_X_MAX 424
#define M_Y_MAX 295
#define M_Z_MAX 472

#define Kp_ROLLPITCH 0.02
#define Ki_ROLLPITCH 0.00002
#define Kp_YAW 1.2
#define Ki_YAW 0.00002

 /*For debugging purposes*/
 //OUTPUTMODE=1 will print the corrected data, 
 //OUTPUTMODE=0 will print uncorrected data of the gyros (with drift)
#define OUTPUTMODE 1

//#define PRINT_DCM 0     //Will print the whole direction cosine matrix
 #define PRINT_ANALOGS 0 //Will print the analog raw data
 #define PRINT_EULER 1   //Will print the Euler angles Roll, Pitch and Yaw

 #define STATUS_LED 13 

float G_Dt=0.02;    // Integration time (DCM algorithm)  We will run the integration loop at 50Hz      if possible

long timer=0;   //general purpuse timer
long timer_old;
long timer24=0; //Second timer used to print values 
int AN[6]; //array that stores the gyro and accelerometer data
int AN_OFFSET[6]={0,0,0,0,0,0}; //Array that stores the Offset of the sensors

int gyro_x;
int gyro_y;
int gyro_z;
int accel_x;
int accel_y;
int accel_z;
int magnetom_x;
int magnetom_y;
int magnetom_z;
float c_magnetom_x;
float c_magnetom_y;
float c_magnetom_z;
float MAG_Heading;

float Accel_Vector[3]= {0,0,0}; //Store the acceleration in a vector
float Gyro_Vector[3]= {0,0,0};//Store the gyros turn rate in a vector
float Omega_Vector[3]= {0,0,0}; //Corrected Gyro_Vector data
float Omega_P[3]= {0,0,0};//Omega Proportional correction
float Omega_I[3]= {0,0,0};//Omega Integrator
float Omega[3]= {0,0,0};

// Euler angles
float roll;
float pitch;
float yaw;

float errorRollPitch[3]= {0,0,0}; 
float errorYaw[3]= {0,0,0};

unsigned int counter=0;
byte gyro_sat=0;

float DCM_Matrix[3][3]= {
{
1,0,0  }

float Temporary_Matrix[3][3]={
 {
 0,0,0  }
 ,{
  0,0,0  }
 ,{
  0,0,0  }
};

void setupattitude()
{ 
Serial.begin(115200);
pinMode (STATUS_LED,OUTPUT);  // Status LED

I2C_Init();


digitalWrite(STATUS_LED,LOW);
delay(1500);

Accel_Init();
Compass_Init();
Gyro_Init();

delay(20);

for(int i=0;i<32;i++)    // We take some readings...
{
Read_Gyro();
Read_Accel();
for(int y=0; y<6; y++)   // Cumulate values
  AN_OFFSET[y] += AN[y];
delay(20);
}

for(int y=0; y<6; y++)
  AN_OFFSET[y] = AN_OFFSET[y]/32;

AN_OFFSET[5]-=GRAVITY*SENSOR_SIGN[5];

//Serial.println("Offset:");
for(int y=0; y<6; y++)
  Serial.println(AN_OFFSET[y]);

delay(2000);
digitalWrite(STATUS_LED,HIGH);

timer=millis();
delay(20);
counter=0;
}

void loopattitude()
{
 if((millis()-timer)>=20)  // Main loop runs at 50Hz
{
counter++;
timer_old = timer;
timer=millis();
if (timer>timer_old)
  G_Dt = (timer-timer_old)/1000.0;    // Real time of loop run. We use this on the DCM algorithm     (gyro integration time)
else
  G_Dt = 0;

// *** DCM algorithm
// Data adquisition
Read_Gyro();   // This read gyro data
Read_Accel();     // Read I2C accelerometer

if (counter > 5)  // Read compass data at 10Hz... (5 loop runs)
  {
  counter=0;
  Read_Compass();    // Read I2C magnetometer
  Compass_Heading(); // Calculate magnetic heading  
  }

// Calculations...
Matrix_update(); 
Normalize();
Drift_correction();
Euler_angles();
// ***

Serial.println(roll);
Serial.println(pitch);
 }

}

3V3 - VIN
GND - GND
SDA - SDA
SCL - SCL

Arduino: 1.8.7 (Linux), Board: "Arduino Nano, ATmega328P"

/home/hitesh/cart_ws/src/acs/razor_imu_9dof/src/Razor_AHRS/Razor_AHRS.ino: In function 'void read_sensors()':
Razor_AHRS:584:13: error: 'Read_Gyro' was not declared in this scope
   // Normally using x-z-plane-component/y-component of compensated gravity vector
             ^
Razor_AHRS:585:14: error: 'Read_Accel' was not declared in this scope
   // roll = atan2(temp2[1], sqrt(temp2[0] * temp2[0] + temp2[2] * temp2[2]));
              ^
Razor_AHRS:586:13: error: 'Read_Magn' was not declared in this scope
   // Since we compensated for pitch, x-z-plane-component equals z-component:
             ^
/home/hitesh/cart_ws/src/acs/razor_imu_9dof/src/Razor_AHRS/Razor_AHRS.ino: In function 'void compensate_sensor_errors()':
Razor_AHRS:622:78: error: 'Matrix_Vector_Multiply' was not declared in this scope
/home/hitesh/cart_ws/src/acs/razor_imu_9dof/src/Razor_AHRS/Razor_AHRS.ino: In function 'void reset_sensor_fusion()':
Razor_AHRS:655:43: error: 'Vector_Cross_Product' was not declared in this scope
Razor_AHRS:663:19: error: 'Compass_Heading' was not declared in this scope
   delay(400);  // Give sensors enough time to collect data
                   ^
Razor_AHRS:667:52: error: 'init_rotation_matrix' was not declared in this scope
/home/hitesh/cart_ws/src/acs/razor_imu_9dof/src/Razor_AHRS/Razor_AHRS.ino: In function 'void setup()':
Razor_AHRS:728:12: error: 'I2C_Init' was not declared in this scope
         else if (output_param == 'c') // Go to _c_alibration mode
            ^
Razor_AHRS:729:14: error: 'Accel_Init' was not declared in this scope
Razor_AHRS:730:13: error: 'Magn_Init' was not declared in this scope
           output_mode = OUTPUT__MODE_CALIBRATE_SENSORS;
             ^
Razor_AHRS:731:13: error: 'Gyro_Init' was not declared in this scope
           reset_calibration_session_flag = true;
             ^
/home/hitesh/cart_ws/src/acs/razor_imu_9dof/src/Razor_AHRS/Razor_AHRS.ino: In function 'void loop()':
Razor_AHRS:1058:91: error: 'output_calibration' was not declared in this scope
Razor_AHRS:1069:23: error: 'Compass_Heading' was not declared in this scope
Razor_AHRS:1070:21: error: 'Matrix_update' was not declared in this scope
Razor_AHRS:1071:17: error: 'Normalize' was not declared in this scope
Razor_AHRS:1072:24: error: 'Drift_correction' was not declared in this scope
Razor_AHRS:1073:20: error: 'Euler_angles' was not declared in this scope
Razor_AHRS:1076:63: error: 'output_angles' was not declared in this scope
Razor_AHRS:1087:23: error: 'Compass_Heading' was not declared in this scope
Razor_AHRS:1088:21: error: 'Matrix_update' was not declared in this scope
Razor_AHRS:1089:17: error: 'Normalize' was not declared in this scope
Razor_AHRS:1090:24: error: 'Drift_correction' was not declared in this scope
Razor_AHRS:1091:20: error: 'Euler_angles' was not declared in this scope
Razor_AHRS:1094:85: error: 'output_both_angles_and_sensors_text' was not declared in this scope
Razor_AHRS:1098:64: error: 'output_sensors' was not declared in this scope
/home/hitesh/cart_ws/src/acs/razor_imu_9dof/src/Razor_AHRS/DCM.ino: In function 'void Normalize()':
DCM:12:65: error: 'Vector_Dot_Product' was not declared in this scope
   error= -Vector_Dot_Product(&DCM_Matrix[0][0],&DCM_Matrix[1][0])*.5; //eq.19
                                                                 ^
DCM:14:58: error: 'Vector_Scale' was not declared in this scope
   Vector_Scale(&temporary[0][0], &DCM_Matrix[1][0], error); //eq.19
                                                          ^
DCM:17:67: error: 'Vector_Add' was not declared in this scope
   Vector_Add(&temporary[0][0], &temporary[0][0], &DCM_Matrix[0][0]);//eq.19
                                                                   ^
DCM:20:74: error: 'Vector_Cross_Product' was not declared in this scope
   Vector_Cross_Product(&temporary[2][0],&temporary[0][0],&temporary[1][0]); // c= a x b //eq.20
                                                                          ^
/home/hitesh/cart_ws/src/acs/razor_imu_9dof/src/Razor_AHRS/DCM.ino: In function 'void Drift_correction()':
DCM:54:77: error: 'Vector_Cross_Product' was not declared in this scope
   Vector_Cross_Product(&errorRollPitch[0],&Accel_Vector[0],&DCM_Matrix[2][0]); //adjust the ground of reference
                                                                             ^
DCM:55:72: error: 'Vector_Scale' was not declared in this scope
   Vector_Scale(&Omega_P[0],&errorRollPitch[0],Kp_ROLLPITCH*Accel_weight);
                                                                        ^
DCM:58:44: error: 'Vector_Add' was not declared in this scope
   Vector_Add(Omega_I,Omega_I,Scaled_Omega_I);     
                                            ^
/home/hitesh/cart_ws/src/acs/razor_imu_9dof/src/Razor_AHRS/DCM.ino: In function 'void Matrix_update()':
DCM:85:53: error: 'Vector_Add' was not declared in this scope
   Vector_Add(&Omega[0], &Gyro_Vector[0], &Omega_I[0]);  //adding proportional term
                                                     ^
DCM:113:60: error: 'Matrix_Multiply' was not declared in this scope
   Matrix_Multiply(DCM_Matrix,Update_Matrix,Temporary_Matrix); //a*b=c
                                                            ^
exit status 1
'Read_Gyro' was not declared in this scope