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Python RGB Demo Not Working

Pixy Software
#1

Hello all, I am using a RPI 4 and am utilizing Thonny Python compiler to execute all my codes. I currently have gone through all the procedures in the wiki link that the Pixy2 Camera currently has to troubleshoot and etc. I can get the code to compile in the linux command window, but I can not use Pixymon at the same time. I must just see the code run and see nothing throughout the Pixymon window. This I don’t really care about.

What I am most desperate to find the solution to is all the errors that I keep getting when running hte RGB Demo Script in Python. Currently I receive these errors:

Python 3.7.3 (/usr/bin/python3)

%Run get_rgb_demo.py
Traceback (most recent call last):
File “/home/pi/pixy2/build/python_demos/pixy.py”, line 14, in swig_import_helper
return importlib.import_module(mname)
File “/usr/lib/python3.7/importlib/init.py”, line 127, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File “”, line 1006, in _gcd_import
File “”, line 983, in _find_and_load
File “”, line 967, in _find_and_load_unlocked
File “”, line 670, in _load_unlocked
File “”, line 583, in module_from_spec
File “”, line 1043, in create_module
File “”, line 219, in _call_with_frames_removed
ImportError: /home/pi/pixy2/build/python_demos/_pixy.so: undefined symbol: PyInstance_Type

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File “/home/pi/pixy2/build/python_demos/get_rgb_demo.py”, line 2, in
import pixy
File “/home/pi/pixy2/build/python_demos/pixy.py”, line 17, in
_pixy = swig_import_helper()
File “/home/pi/pixy2/build/python_demos/pixy.py”, line 16, in swig_import_helper
return importlib.import_module(’_pixy’)
File “/usr/lib/python3.7/importlib/init.py”, line 127, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
ImportError: /home/pi/pixy2/build/python_demos/_pixy.so: undefined symbol: PyInstance_Type

I know I’m dealing with a later version of Python and I plan to change it to 3 or 2 because of what was mentioned in the wiki link but I would love to be able to manipulate this file for my senior design project. Any help would be greatly appreciated. Thank you

#2

Hello,
The Python support uses libpixyusb2. Go into the scripts directory (at the root of the repository) and run “build_all.sh” to make sure that everything is built and then try to run the Python demos.

Edward

#3

I have the same issue (Python 3.7.3), but have figured out that the script can be run when using the sudo command in the terminal. However, I cannot use any script from build/python_demos in an IDE (I am using Thonny on a Raspberry Pi 4).

How can I run this inside Thonny?

#4

I figured out that the PixyMon for linux tutorial has the answer.

2.2.3. Add permissions for Pixy USB interface

In order to communicate with Pixy over USB as a non-root user you must set permissions for Pixy.

To do this copy the ‘pixy.rules’ file to ‘/etc/udev/rules.d’

In the terminal window type:

cd ../src/host/linux/ <— this is while inside of the pixy2 folder
sudo cp pixy.rules /etc/udev/rules.d/ <— this copies the pixy.rules file into the udev folder (granting permissions)

1 Like
#5

Thanks for the good suggestion Stew!