Skip to content

ValueError: PyCapsule_New called with null pointer #14

Description

@VKD19

I am trying to display the real time data of a instrument which communicating through serial port with baudrate of 9600. System streaming data in every 1 min. some time not streaming for 5 minutes.
I have written the code and its working but sum time not working due to error ValueError: PyCapsule_New called with null pointer.
My code is follows...

    import serial
    import time
    import keyboard
    from itertools import islice
    import csv
    from drawnow import *
    import numpy
    import matplotlib.pyplot as plt
    from datetime import datetime

    BC880 = []

   def makeFig():
           plt.plot(BC880, 'ko', label='Black Carbon Conc. (ng m-3)')
           plt.legend(loc='upper left')

  Ser = serial.Serial('COM5')
  while True:
          res = Ser.readline()
          decoded_bytes = res.decode('utf-8')
          AE33data = islice(decoded_bytes.split(","), 11)
          list_AE33data = list(AE33data)
          print(list_AE33data)
          with open("AE33_data.csv","a") as f:
                   writer = csv.writer(f,delimiter=",")
                   writer.writerow(list_AE33data)

          BC = int(list_AE33data[8])
          BC880.append(BC)
          drawnow(makeFig)

   Ser.close()
   print('Serial Port Disconnected')

I am getting following error
Traceback (most recent call last):
File "C:/Users/AML/AppData/Local/Programs/Python/Python312/test.py", line 30, in
drawnow(makeFig)
File "C:\Users\AML\AppData\Local\Programs\Python\Python312\Lib\site-packages\drawnow\drawnow.py", line 72, in drawnow
plt.clf()
File "C:\Users\AML\AppData\Local\Programs\Python\Python312\Lib\site-packages\matplotlib\pyplot.py", line 1195, in clf
gcf().clear()
File "C:\Users\AML\AppData\Local\Programs\Python\Python312\Lib\site-packages\matplotlib\pyplot.py", line 1088, in gcf
return figure()
File "C:\Users\AML\AppData\Local\Programs\Python\Python312\Lib\site-packages\matplotlib\pyplot.py", line 1022, in figure
manager = new_figure_manager(
File "C:\Users\AML\AppData\Local\Programs\Python\Python312\Lib\site-packages\matplotlib\pyplot.py", line 545, in new_figure_manager
return _get_backend_mod().new_figure_manager(*args, **kwargs)
File "C:\Users\AML\AppData\Local\Programs\Python\Python312\Lib\site-packages\matplotlib\backend_bases.py", line 3521, in new_figure_manager
return cls.new_figure_manager_given_figure(num, fig)
File "C:\Users\AML\AppData\Local\Programs\Python\Python312\Lib\site-packages\matplotlib\backend_bases.py", line 3526, in new_figure_manager_given_figure
return cls.FigureCanvas.new_manager(figure, num)
File "C:\Users\AML\AppData\Local\Programs\Python\Python312\Lib\site-packages\matplotlib\backend_bases.py", line 1811, in new_manager
return cls.manager_class.create_with_canvas(cls, figure, num)
File "C:\Users\AML\AppData\Local\Programs\Python\Python312\Lib\site-packages\matplotlib\backends_backend_tk.py", line 479, in create_with_canvas
with _restore_foreground_window_at_end():
File "C:\Users\AML\AppData\Local\Programs\Python\Python312\Lib\contextlib.py", line 137, in enter
return next(self.gen)
File "C:\Users\AML\AppData\Local\Programs\Python\Python312\Lib\site-packages\matplotlib\backends_backend_tk.py", line 43, in _restore_foreground_window_at_end
foreground = _c_internal_utils.Win32_GetForegroundWindow()
ValueError: PyCapsule_New called with null pointer

Expected data printing and plotting by code in real time:
['0683', '"06-Jun-24"', '"15:06"', ' 635', ' 656', ' 557', ' 554', ' 484', ' 431', ' 419', ' 3.0']
['0683', '"06-Jun-24"', '"15:07"', ' -40', ' 45', ' 146', ' 6', ' -37', ' -97', ' -56', ' 3.0']
['0683', '"06-Jun-24"', '"15:08"', ' 1086', ' 1089', ' 862', ' 843', ' 777', ' 809', ' 765', ' 3.0']
['0683', '"06-Jun-24"', '"15:09"', ' 996', ' 909', ' 1013', ' 890', ' 801', ' 800', ' 871', ' 3.0']
['0683', '"06-Jun-24"', '"15:10"', ' 1441', ' 1387', ' 1219', ' 1219', ' 1162', ' 1158', ' 1113', ' 3.0']
['0683', '"06-Jun-24"', '"15:11"', ' 735', ' 796', ' 679', ' 624', ' 535', ' 545', ' 501', ' 3.0']
['0683', '"06-Jun-24"', '"15:12"', ' 503', ' 493', ' 504', ' 509', ' 395', ' 305', ' 359', ' 3.0']
['0683', '"06-Jun-24"', '"15:13"', ' 326', ' 366', ' 259', ' 153', ' 173', ' 132', ' 148', ' 3.0']
['0683', '"06-Jun-24"', '"15:14"', ' 746', ' 705', ' 753', ' 673', ' 538', ' 594', ' 591', ' 3.0']
['0683', '"06-Jun-24"', '"15:15"', ' 759', ' 859', ' 673', ' 756', ' 599', ' 643', ' 566', ' 3.0']
['0683', '"06-Jun-24"', '"15:16"', ' 1247', ' 1236', ' 1163', ' 1019', ' 1059', ' 955', ' 1025', ' 3.0']
['0683', '"06-Jun-24"', '"15:17"', ' 1650', ' 1438', ' 1438', ' 1441', ' 1331', ' 1391', ' 1420', ' 3.0']
['0683', '"06-Jun-24"', '"15:18"', ' 1021', ' 980', ' 919', ' 942', ' 801', ' 896', ' 773', ' 3.0']
['0683', '"06-Jun-24"', '"15:19"', ' 816', ' 863', ' 930', ' 749', ' 687', ' 629', ' 688', ' 3.0']
Real time plot:
Figure_1

Please help me to solve this issue
Thank you

Activity

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Metadata

Metadata

Assignees

No one assigned

    Labels

    No labels
    No labels

    Projects

    No projects

      Milestone

      No milestone

      Relationships

      None yet

      Development

      No branches or pull requests

      Issue actions