hi
i am noob i had run your program
for my school project and run pretty well
but reinstall raspberry and i install everything
without errors by instructions left.
and now when i start the program and when it see rubik's cube
show me some errors like this
pi@raspberrypi:~ $ rubiks-cube-tracker.py --webcam 0 Traceback (most recent call last): File "/usr/local/bin/rubiks-cube-tracker.py", line 49, in <module> rvid.analyze_webcam() File "/usr/local/lib/python2.7/dist-packages/rubikscubetracker/__init__.py", line 1711, in analyze_webcam if self.analyze(webcam=True): File "/usr/local/lib/python2.7/dist-packages/rubikscubetracker/__init__.py", line 1417, in analyze missing = self.find_missing_squares(missing_count) File "/usr/local/lib/python2.7/dist-packages/rubikscubetracker/__init__.py", line 1202, in find_missing_squares self.set_contour_row_col_index(con) File "/usr/local/lib/python2.7/dist-packages/rubikscubetracker/__init__.py", line 979, in set_contour_row_col_index row_size = round(cube_height / float(self.median_square_width + self.black_border_width)) ZeroDivisionError: float division by zero pi@raspberrypi:~ $ rubiks-cube-tracker.py --webcam 0 Traceback (most recent call last): File "/usr/local/bin/rubiks-cube-tracker.py", line 49, in <module> rvid.analyze_webcam() File "/usr/local/lib/python2.7/dist-packages/rubikscubetracker/__init__.py", line 1711, in analyze_webcam if self.analyze(webcam=True): File "/usr/local/lib/python2.7/dist-packages/rubikscubetracker/__init__.py", line 1407, in analyze self.get_black_border_width() File "/usr/local/lib/python2.7/dist-packages/rubikscubetracker/__init__.py", line 1050, in get_black_border_width "black_border_width %s, median_square_width %s" % (self.black_border_width, self.median_square_width) AssertionError: black_border_width 23, median_square_width 15

Hi, i want to ask you if it's s possible to use raspberry pi camera instead a webcam. Sorry for making this an issue and hope you will reply to this. Thanks!

Hello,
I just updated the version of this project (last update was in april 2018) and do this command:
rubiks-cube-tracker.py --directory /home/pi/cubescan
But give me this error:

2019-04-25 09:10:20,990 init.py INFO: Analyze /home/pi/cubescan/rubiks-side-U.png
Traceback (most recent call last):
File "/usr/local/bin/rubiks-cube-tracker.py", line 74, in
rimg.analyze_file(filename, cube_size)
File "/usr/local/lib/python2.7/dist-packages/rubikscubetracker/init.py", line 1555, in analyze_file
return self.analyze(webcam=False, cube_size=cube_size)
File "/usr/local/lib/python2.7/dist-packages/rubikscubetracker/init.py", line 1407, in analyze
self.get_black_border_width()
File "/usr/local/lib/python2.7/dist-packages/rubikscubetracker/init.py", line 1050, in get_black_border_width
"black_border_width %s, median_square_width %s" % (self.black_border_width, self.median_square_width)
AssertionError: black_border_width 60, median_square_width 21
Exception in Tkinter callback
Traceback (most recent call last):
File "/usr/lib/python2.7/lib-tk/Tkinter.py", line 1545, in call
return self.func(*args)
File "window.py", line 42, in first
cube3.analizer()
File "/home/pi/cube3.py", line 724, in analizer
output1 = check_output(cmd1, shell=True)
File "/usr/lib/python2.7/subprocess.py", line 219, in check_output
raise CalledProcessError(retcode, cmd, output=output)
CalledProcessError: Command 'rubiks-cube-tracker.py --directory /home/pi/cubescan' returned non-zero exit status 1

I tested the same image in the previous update and worked perfect. I need to do this comand instead of -webcam because this is the way i implemented it in my software (I work to a robot that can solve the 3x3x3 cube). Here is my image:

If you can help me with that or maybe just give me the previous version and how to intall it because i'm new to linux (use the raspberry pi3 now - also for the robot project).#

THANKS in advance,
Steven

I'm having a nightmare trying to get my EV3/BrickPi3 Rubik's cube solver robot to work after having to re-install the software from scratch (SD card threw in the towel and no back-up image!)

Running BricKuber.py the message I was getting yesterday was as follows:

Taking pictures of each face, and determining cube configuration.
START: Read Face Colors: top
Picture taken
Failed in processing image: 2022-10-04 20:11:36,396            __init__.py     INFO: Analyze /tmp/BricKuber_top_face.jpg
Traceback (most recent call last):
  File "/usr/local/bin/rubiks-cube-tracker.py", line 56, in <module>
    rimg.analyze_file(args.filename)
  File "/usr/local/lib/python3.7/dist-packages/rubikscubetracker/__init__.py", line 1685, in analyze_file
    return self.analyze(webcam=False, cube_size=cube_size)
  File "/usr/local/lib/python3.7/dist-packages/rubikscubetracker/__init__.py", line 1531, in analyze
    self.get_black_border_width(webcam)
File "/usr/local/lib/python3.7/dist-packages/rubikscubetracker/__init__.py", line 1134, in 
get_black_border_width
         ), f"black_border_width  {self.black_border_width},  median_square_width  {self.median_square_width}"
 AssertionError: black_border_width 94,  median_square_width 39

which to my untutored eye seemed to be saying that the black border was wider than the detected square.

I left it at that for the rest of the day and came back to the problem this evening. I printed out the whole of 'init.py' in an attempt to trace the flow through the code. Much to my surprise, when I ran BricKuber.py again I got a different error:

Taking pictures of each face, and determining cube configuration.
START: Read Face Colors: top
Picture taken
Failed in processing image: 2022-10-04 20:11:36,396            __init__.py     INFO: Analyze /tmp/BricKuber_top_face.jpg
Traceback (most recent call last):
  File "/usr/local/bin/rubiks-cube-tracker.py", line 56, in <module>
    rimg.analyze_file(args.filename)
  File "/usr/local/lib/python3.7/dist-packages/rubikscubetracker/__init__.py", line 1685, in analyze_file
    return self.analyze(webcam=False, cube_size=cube_size)
  File "/usr/local/lib/python3.7/dist-packages/rubikscubetracker/__init__.py", line 1531, in analyze
    self.get_black_border_width(webcam)
AttributeError: 'RubiksImage' object has no attribute 'get_black_border_width'

As far as I'm aware I haven't altered the code in any way nor reinstalled any packages but the Class RubiksImage has no attribute 'get_black_border_width'

Please can you throw any light on this puzzle?

The cube scanning seems to be confusing between red and orange for me. I have tried Pi Camera v1.3 as well as v2.0. I have also tried multiple cubes and played around with many settings (AWB gains, contrast, mode etc), but it still gets confused between red and orange on alternate squares. See the attached file - which is the output from the color-resolver program.

rubiks-color-resolver.html.zip

my Rubik's cube is 3x3x3 ,but it find only 2x2x2

Is line 1307 in __init__.py supposed to be elif con.row_index == row_index + 1: instead of elif con.row_index == row_index - 1:?

This photo fails an assert . Any idea why? All other faces are good to go.

pi@raspberrypi:~/brickuber $ rubiks-cube-tracker.py --filename ./BricKuber_back_face.jpg
2020-03-24 15:02:16,739            __init__.py     INFO: Analyze ./BricKuber_back_face.jpg
Traceback (most recent call last):
  File "/usr/local/bin/rubiks-cube-tracker.py", line 65, in <module>
    rimg.analyze_file(args.filename)
  File "/usr/local/lib/python2.7/dist-packages/rubikscubetracker/__init__.py", line 1832, in analyze_file
    return self.analyze(webcam=False, cube_size=cube_size)
  File "/usr/local/lib/python2.7/dist-packages/rubikscubetracker/__init__.py", line 1669, in analyze
    self.get_black_border_width(webcam)
  File "/usr/local/lib/python2.7/dist-packages/rubikscubetracker/__init__.py", line 1220, in get_black_border_width     
    % (self.black_border_width, self.median_square_width)
AssertionError: black_border_width 75, median_square_width 33

Hi dwalton!

I was trying your codes :) but I got some errors with the cube's tracker, looks like it is not getting access to the webcam? here the error log...

> Traceback (most recent call last):
>   File "rubiks-cube-tracker.py", line 48, in <module>
>     rvid.analyze_webcam()
>   File "/Users/Manuel/miniconda2/lib/python2.7/site-packages/rubikscubetracker/__init__.py", line 1632, in analyze_webcam
>     if self.analyze(webcam=True):
>   File "/Users/Manuel/miniconda2/lib/python2.7/site-packages/rubikscubetracker/__init__.py", line 1261, in analyze
>     (_, contours, hierarchy) = cv2.findContours(dilated.copy(), cv2.RETR_TREE, cv2.CHAIN_APPROX_SIMPLE)
> ValueError: need more than 2 values to unpack
> Cleaned up camera.

Any idea? Thanks!
Cheers,

BTW, very nice blog ;)

Hi Daniel,

Not sure if anyone will be interested but I've modified brickuber_lib.py for use under RaspiOS Bullseye.

With the advent of Bullseye, raspistill was removed from the repository and the use of libcamera-still was mandated. It turned out to be not very difficult to implement this. There were a couple of gotchas but I had a new install of Bullseye with all the software up and running in a little under a day of my time (part-time).

Later: this issue is slightly complicated as, hidden in the small print in the documentation for the camera, it says that libcamera is only mandated if you’re using the 64-bit version of Bullseye. If using the 32-bit version, the revert to legacy camera stack is allowed and raspistill is available from the repo. I had opted for the 64-bit version so was constrained.

In the process I changed all the:

if(cmd.find("U") != -1):

instances to that recommended by the Python3 documentation i.e.

if("U" in cmd):

Python Standard Library states:

Note The find() method should be used only if you need to know the position of sub. 
To check if sub is a substring or not, use the in operator:
>>>
>>> 'Py' in 'Python'
True

There are a couple of additional lines to add to /boot/config.txt

dtoverlay=imx219 if you're using a Raspberry Pi Camera V2.x
camera_autodetect=1
dtoverlay=vc4-kms-v3d

The latter 2 are added when you run raspi-config and configure for camera but the imx219 is needed for V2.x cameras.

The code to use the libcamera-still program is:

 subprocess.run(['libcamera-still', '--width=300', '--height=300', '-v', 
'0', '-n', '-t', '1', '--sharpness', '-100', '-o', filename])

which replaces the original line using raspistill.

I have also hacked together a cube randomiser. It is pretty crude and would certainly not satisfy the WCA competition rules but it saves me juggling with a cube. It uses the BricKuber robot and brickuber_lib.py to make the moves. Unlike the WCA code it disallows successive moves on the same face. A minor point but one which offended my OCD. :-)

I can upload the modified brickuber_lib.py and Scrambler.py if you're interested.

A slight niggle: running Bullseye on my Pi3B is unstable and the system sometimes hangs. The only way to recover is to cycle power. I hold my breath each time I'm forced to do that.

BTW I reinstated all the original motor speed values to those in the original code and the cube stays in the cradle. That speeded up the overall solve time somewhat too.

Another oddity: If you present the system with a solved cube, it still comes up with a few moves which do ultimately produce a solved cube. Seems like there is a test for solved missing somewhere in the code?