error: redefinition of class

Using Arduino Programming Questions
#1

Hi,

I am trying to make this project found on yt work: MPU6050 GY-521 + L298N Arduino R3 + Stepper motor Knob Control - YouTube

But I have a problem, when I’m trying to compile the whole code this error appear everythime:

Arduino: 1.8.8 (Windows 10), Board: "Arduino/Genuino Uno"

Kalman.h:18:7: error: redefinition of 'class Kalman'

 class Kalman {

       ^

In file included from C:\Users\Rares\Documents\Arduino\var2\var2.ino:1:0:

C:\Users\Rares\Documents\Arduino\libraries\libraries\Kalman_Filter_Library/Kalman.h:21:7: error: previous definition of 'class Kalman'

 class Kalman {

       ^

exit status 1
redefinition of 'class Kalman'

The code uses 2 libraryes:
Kalman, from where the error provide and I2C.

I attached the libraries and the main code.

Can anyone help me? Any ideea? Please.

Sorry if I said something wrong, I’m still learning :slight_smile:

Kalman.h.ino (4.34 KB)

I2C.ino.ino (2.36 KB)

var2.ino (7.33 KB)

#2

Some confusion of file types going on I think.

You are not by any chance using Windows with the "hide the file types so that I can't see what is going on" option turned on are you ?

#3

I am not, all files are visible. But how that can that affect my code?

#4

The files may be visible but what about their extensions ? .ino .h etc

Look at the file named Kalman Should it be a .h or a .ino file. My guess is that you have "hide file types" turned on so what you see is Kalman.h whereas its name is really Kalman.h.ino so is an ino file

#5

Yes, you're right. It's Kalman.h.ino. So it's should be just a Kalman.h file?

#6

Don’t put library files in your sketch. You already have the library installed:

rares351:

In file included from C:\Users\Rares\Documents\Arduino\var2\var2.ino:1:0:

C:\Users\Rares\Documents\Arduino\libraries\libraries\Kalman_Filter_Library/Kalman.h:21:7: error: previous definition of ‘class Kalman’

class Kalman {

^

Just delete Kalman.h.ino and I2C.h.ino.

#7

Yess. It works. Thanks a lot !! :money_mouth_face: :smiley:

#8

You're welcome. I'm glad to hear it's working now. Enjoy!
Per

#9