ERROR:can.socketcan.ctypes:Setting filters failed -1 Find out the can error frame

See also questions close to this topic

• Module with globals or Class with attributes?

  Currently I'm working with a lot of modules where the original developers used global variables to control states and to exchange important information between functions, like so:

  STATE_VAR = 0
  
  def do_something(arg1):
      global STATE_VAR
      if arg1:
          STATE_VAR = 1
  
  def say_hello():
      if STATE_VAR:
          print("Hello!")
  

  I have to create new libraries that communicate with these modules and, once I use pylint to check on my code, I get a lot of complaints about using global.

  In my head, the structure should be something like this:

  class MyClass:
      STATE_VAR = 0
  
      @classmethod
      def do_something(cls, arg1):
          if arg1:
              cls.STATE_VAR = 1
  
      @classmethod
      def say_hello(cls):
          if cls.STATE_VAR:
              print("Hello!")
  

  This structure makes pylint happy for not using the global statement, but at the same time, rubs me in the wrong way for the need to use clauses such as from mymodule import MyClass, or have to contend with the ugly mymodule.MyClass.do_something() type of call.

  I wanted to develop my code that is both pythonic and also consistent with what is already in place (I might be overthinking this as well).

  I've also stumbled upon this other related question that got no definitive answer to it.

  So my question is: What is the best practice in this situation. Do I keep writing code that are modules using global variables to define state (keep consistency but let pylint mad) or should I follow the road of classes and OOP (and effectively go against the code already in place)?
• Breaking subprocess loop from parent process

  What is missing here to break the loop in tok2.py from tok1.py?

  I try to send a string containing 'exit', read the sent value into my_input and break the loop in tok2.py?

  Now tok2 runs forever.

  Using Debian 10 Buster with Python 3.7.

  tok1.py:

  import sys
  import time
  import subprocess
  
  command = [sys.executable, 'tok2.py']
  proc = subprocess.Popen(command, stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
  
  i=0
  while proc.poll() is None:
      if i > 5:
          #Send 'exit' after 5th iteration
          proc.stdin.write(b'exit')
  
      print('tok1: '  + str(i))
  
      time.sleep(0.5)
      i=i+1
  

  tok2.py:

  import sys
  import time
  
  ii=0
  my_input =''
  while True:
      my_input = sys.stdin.read()
  
      if my_input == b'exit':
          print('tok2: exiting')
          sys.stdout.flush()
          break
  
      print('tok2: ' + str(ii))
      sys.stdout.flush()
      ii=ii+1    
      time.sleep(0.5)
  
• TypeError: '>=' not supported between instances of 'builtin_function_or_method' and 'int'

  When i run the below code :

  input("请输入1—100之间的数字：")
  n = input
  if n >= 1 and n <= 100:
      print("你妹好漂亮！")
  else:
      print("你大爷好丑")
  print("游戏结束啦！不和你玩了")
  
  
  if n >= 1 and n <= 100:
  

  I get the following error:

  TypeError: '>=' not supported between instances of 'builtin_function_or_method' and 'int'`
• Socket Network Stream Read from Third-Party Socket API Freezes/Crashes Project

  I'm trying to read a response from a third-party, socket based API and when I try to read what is returned my project freezes. I'm able to connect, send a request, and close the connection without error.

  To test my code I created my own basic server app and my client app works as expected with it. It just doesn't work when I try that same client project against the third-party API.

  Any ideas what could be causing this?

  Here is my code:

  Imports System.Net.Sockets
  Imports System.Text
  
  Public Class Form1
      Dim VarSocketServer As New TcpClient
      Dim VarNetworkStream As NetworkStream
  
      Private Sub Form2_Load(sender As Object, e As EventArgs) Handles MyBase.Load
          VarSocketServer.Connect("127.0.0.1", 28192)
      End Sub
  
      Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
          Dim VarNetworkStream As NetworkStream = VarSocketServer.GetStream()
  
          ' Send a msessage/request to the server. This doesn't return errors and appears to work.
          Dim VarClientRequest As String = "{My request is sent in JSON and includes credentials and key}"
          Dim VarSendByte As [Byte]() = System.Text.Encoding.ASCII.GetBytes(VarClientRequest)
          VarNetworkStream.Write(VarSendByte, 0, VarSendByte.Length)
          VarNetworkStream.Flush()
  
          ' Read the response from the server. This freezes at "VarNetworkStream.Read"
          Dim VarInStream(10024) As Byte
          Dim VarBytesRead = VarNetworkStream.Read(VarInStream, 0, VarInStream.Length)
          Dim VarDataFromServer As String = System.Text.Encoding.ASCII.GetString(VarInStream)
          VarNetworkStream.Flush()
  
          Console.WriteLine(">> Data from server: " + VarDataFromServer)
         Console.ReadLine()
      End Sub
  
      Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
          VarSocketServer.Close()
          Me.Close()
      End Sub
  End Class
  
• What library should I use to get high-level event-driven sockets in Python?

  I am creating an application that uses Python socket module for communication. Currently I am having a while True loop but it looks awful and complexity level is high. I want some form of event-driven TCP socket library like net in NodeJS:

  client.on('data', function(data) {
      console.log('Received: ' + data);
  });
  
• Java IOException Stream Closed in Server Client program

  I am trying to make a Server Client program that allows sending multiple messages from server to client or vice versa without waiting for a response. The program works fine when the first client is connected and disconnected. But when I connect the client again, I get the error. Here is my server code:

  import java.io.DataInputStream;
  import java.io.DataOutputStream;
  import java.io.IOException;
  import java.net.ServerSocket;
  import java.net.Socket;
  import java.net.SocketException;
  
  import java.io.InputStreamReader;
  
  import java.io.BufferedReader;
  
  class Q2Server implements Runnable{
      private ServerSocket serverSocket;
      private Socket socket;
      private DataOutputStream out;
      private BufferedReader in1;
      private DataInputStream in2;
      private Thread read, write;
      private String clientMsg, serverMsg;
  
      public Q2Server (int port) throws IOException{
          serverSocket = new ServerSocket(port);
  
          while(true) {
              try {
                  System.out.println("Waiting for client on port " + serverSocket.getLocalPort() + "...");
                  socket = serverSocket.accept();
  
                  System.out.println("Just connected to " + socket.getRemoteSocketAddress());
  
                  out = new DataOutputStream(socket.getOutputStream());
                  out.writeUTF("Thanks for connecting to " + socket.getLocalSocketAddress());
  
                  clientMsg = "";
                  serverMsg = "";
  
                  read = new Thread(this);
                  write = new Thread(this);
  
                  read.start();
                  write.start();
  
                  read.join();
                  write.join();
  
              } catch(IOException e) {
                  e.printStackTrace();
              } catch(InterruptedException ie) {
                  ie.printStackTrace();
              }
          }
  
      }
  
      public void run () {
          try {
              if(Thread.currentThread() == write) {
                  while(true) {
                      try {
                          if(clientMsg.equals("close")) {
                              break;
                          } else {
                              in1 = new BufferedReader(new InputStreamReader(System.in));
                              out = new DataOutputStream(socket.getOutputStream());
                              serverMsg = in1.readLine();
                              out.writeUTF(serverMsg);
                              if(serverMsg.equals("close")) {
                                  socket.close();
                                  in1.close();
                                  in2.close();
                                  out.close();
                                  System.out.println("Closing connection...");
                                  break;
                              }    
                          }
                      } catch (SocketException s) {
                          break;
                      } 
  
                  } 
  
              } else {
                  while(true) {
                      try {
                          if(serverMsg.equals("close")) {
                              break;
                          }
                          in2 = new DataInputStream(socket.getInputStream());
                          clientMsg = in2.readUTF();
                          System.out.println("Client: " + clientMsg);
                          if(clientMsg.equals("close")) {
                              socket.close();
                              in1.close();
                              in2.close();
                              out.close();
                              System.out.println("Closing connection...");
                              break;
                          }
                      } catch(SocketException s) {
                          break;
                      } 
  
                  } 
  
              }
          } catch (IOException i) {
              i.printStackTrace();
          }
      }
      public static void main(String[] args) throws IOException {
          Q2Server server = new Q2Server(8080);
      }
  }
  

  Client code:

  import java.io.DataInputStream;
  import java.io.DataOutputStream;
  import java.io.IOException;
  import java.net.Socket;
  import java.net.SocketException;
  import java.rmi.UnexpectedException;
  
  
  import java.io.InputStreamReader;
  
  import java.io.BufferedInputStream;
  import java.io.BufferedReader;
  import java.lang.Thread;
  
  class Q2Client implements Runnable {
      private Socket socket;
      private Thread read, write;
      private BufferedReader in1;
      private DataInputStream in2;
      private DataOutputStream out;
      private String clientMsg, serverMsg;
  
      public Q2Client(int port) {
          try {
              socket = new Socket("localHost",port);
              System.out.println("Connected to port: " + port);
  
              clientMsg = serverMsg = "";
  
              read = new Thread(this);
              write = new Thread(this);
  
              in2 = new DataInputStream(new BufferedInputStream(socket.getInputStream()));
  
              System.out.println(in2.readUTF());
  
              read.start();
              write.start();
  
              read.join();
              write.join();
  
          } catch(UnexpectedException u) {
              u.printStackTrace();
          } catch(IOException i) {
              i.printStackTrace();
          } catch(InterruptedException ie) {
              ie.printStackTrace();
          }
      }
  
      public void run() {
          try {
              if(Thread.currentThread() == write) {
                  while(true) {
                      try {
                          if(serverMsg.equals("close")) {
                              break;
                          }
                          in1 = new BufferedReader(new InputStreamReader(System.in));
                          out = new DataOutputStream(socket.getOutputStream());
                          clientMsg = in1.readLine();
                          out.writeUTF(clientMsg);
                          if(clientMsg.equals("close")) {
                              socket.close();
                              in1.close();
                              in2.close();
                              out.close();
                              System.out.println("Closing connection...");
                              break;
                          }
                      } catch (SocketException s) {
                          break;
                      } 
  
                  } 
              } else {
                  while(true) {
                      try {
                          if(clientMsg.equals("close")) {
                              break;
                          }
                          in2 = new DataInputStream(socket.getInputStream());
                          serverMsg = in2.readUTF();
                          System.out.println("Server: " + serverMsg);
                          if(serverMsg.equals("close")) {
                              socket.close();
                              in1.close();
                              in2.close();
                              out.close();
                              System.out.println("Closing connection...");
                              break;
                          }
                      } catch (SocketException s) {
                          break;
                      }
  
                  } 
              }
          } catch (IOException i) {
              i.printStackTrace();
          }
  
      }
  
      public static void main(String[] args) {
          Q2Client client = new Q2Client(8080);
      }
  }
  

  Here is the stacktrace of the exception:

  java.io.IOException: Stream closed at java.base/java.io.BufferedInputStream.getBufIfOpen(BufferedInputStream.java:176) at java.base/java.io.BufferedInputStream.read(BufferedInputStream.java:342) at java.base/sun.nio.cs.StreamDecoder.readBytes(StreamDecoder.java:284) at java.base/sun.nio.cs.StreamDecoder.implRead(StreamDecoder.java:326) at java.base/sun.nio.cs.StreamDecoder.read(StreamDecoder.java:178) at java.base/java.io.InputStreamReader.read(InputStreamReader.java:185) at java.base/java.io.BufferedReader.fill(BufferedReader.java:161) at java.base/java.io.BufferedReader.readLine(BufferedReader.java:326) at java.base/java.io.BufferedReader.readLine(BufferedReader.java:392) at Q2Server.run(Q2Server.java:65) at java.base/java.lang.Thread.run(Thread.java:835)

  When either of the server or client sends "close" the connection closes. The client can connect again. But when I run the client code again, I get the exception. What is going wrong and how do I fix this?
• how deal with non-negatively of error in the model?

  I am trying to solve a quadratic program in R. Since my matrix Dmat is not positive definite I am using dykstra to solve it. my model is:

             min W^T* Dmat *W +epsilon
              Wx+b >= 1- epsilon
               epsilon >=0
  

  my problem is I have 9000 row constraints and so 9000 epsilon. when I add epsilon>=0 to Amat, I am adding a 9000 more row in my matrix Amat. this make the dykstra very slow and hard to solve. without adding these constraints my model is solved in 1 minutes but after adding these I can not get result. more than 1 day.... Is there any way to deal with these constraints, both in modelling and solving?
• How to log exception globally without using try catch statement

  I have several try catch statements in my project but I want to log all exceptions without putting it in the catch statement.

  is there any way to monitor all exceptions without putting logging logics in the catch statement like codes down below?

  // codes.
  try {
      // doing something.
  } catch (e) {
     return "error message"
  }
  
  // global.ascx
  protected void Application_Error(object sender, EventArgs e)
  {
     // Logging Logic goes here.
  }
  
• Obtain failure::Fail in actix-web 1.0 Middleware

  I'm using actix-web 1.0

  I'm writing a Middleware that must capture Errors and their stacktrace. The problem is that I can only access ServiceRequests, which contain an actix_web::Error.

  From this I must obtain a failure::Fail, but I can't find any way to do so. Previously I could do Error::as_fail(), but this function isn't available anymore with version 1.0

  How can I obtain an error that implements Fail in my Middleware?
• ATMEGA328p convert analog value to voltage

  This is an extract of the official ATMEGA328p data sheet page 261:

  

  As the documentation say

        Vin * 1024
  ADC = ----------
           Vref
  

  What I don't understand is an analog pin can provide us 10bits. That's mean a value between 0x0 and 0x3ff (1023)

  So I don't understand why the documentation say Vin * 1024 and not 1023. Because for me 0v = 0 and 5v = 1023?
• How to download embedded PDF from website in R?

  I am trying to download a PDF in R, but the PDF is not downloading correctly because the file is hidden in an online interface.

  PDF: https://www.equibase.com/premium/eqbPDFChartPlus.cfm?RACE=A&BorP=P&TID=DMR&CTRY=USA&DT=08/07/2019&DAY=D&STYLE=EQB

  I tried the download.file function but it cannot locate the PDF. I have seen answers around the web point to the package Selenium but I am having a hard time transcribing python into R

  url <- "https://www.equibase.com/premium/eqbPDFChartPlus.cfm?RACE=A&BorP=P&TID=DMR&CTRY=USA&DT=08/07/2019&DAY=D&STYLE=EQB"
  
  download.file(url = url, destfile = "horse.pdf")
  

  I expect a downloaded PDF file.
• Reverse Engineering Fixed Point Numbers

  I am currently putting an engine into another car and I want to keep the fuel economy calulation inside the boardcomputer working. I managed to recode this part sucessfully, but I have been trying to figure out the (simple?) two byte dataformat they used without success. I assume it is fixed point notation, but no matter how I shift it around, it does not line up. How do the two bytes represent the right number?

  Some examples:
  
  Bytes (Dec) --> Result
  174,10 -> 2,67 
  92,11  -> 2,84
  128,22 -> 3,75
  25,29  -> 4,85
  225,23 -> 3,98 
  00,40  -> 5,00 
  128,34 -> 5,75
  
• How to call CAPL general functions from Python 3.x?

  Issue

  I'm trying to call CAPL general functions (in my case timeNowNS) but I don't know if it's possible.

  

  What I'm using?

  I'm using Python 3.7 and Vector CANoe 11.0.

  The connection is done using the .NET CANoe API. This is how i've accesed the DLLs.

  
  import clr
  sys.path.append("C:\Program Files\Vector CANoe 11.0\Exec64")  # path to CANoe DLL Files
  clr.AddReference('Vector.CANoe.Interop')                      # add reference to .NET DLL file
  import CANoe                                                  # import namespace from DLL file
  
  

  What I've tried?

  I opened the CANoe simulation succesfully, started the measure and I'm having access to signals, env variables and sys variables.

  Then I've created the CAPL Object and tried using the GetFunction method to obtain the CAPLFunction object so i could call it.

  def begin_can(self, sCfgFile, fPrjInitFunc = None):
       self.open_can()
       self.load_can_configuration(sCfgFile)
       self.start_can_measurement(fPrjInitFunc)
  
  def open_can(self):
      self.mCANoeApp = CANoe.Application()
      self.mCANoeMeasurement = CANoe.Measurement(self.mCANoeApp.Measurement)
      self.mCANoeEnv = CANoe.Environment(self.mCANoeApp.Environment)
      self.mCANoeBus = CANoe.Bus(self.mCANoeApp.get_Bus("CAN"))
      self.mCANoeSys = CANoe.System(self.mCANoeApp.System)
      self.mCANoeNamespaces = CANoe.Namespaces(self.mCANoeSys.Namespaces)
      self.mCANoeCAPL = CANoe.CAPL(self.mCANoeApp.CAPL)
      self.mCANoeCAPL.Compile()
  
  def getFunction(self):
          function1 = self.mCANoeCAPL.GetFunction('timeNowNS')
  
          # here I tried also CANoe.CAPLFunction(self.mCANoeCAPL.GetFunction('timeNowNS')) 
          # but i got attribute error: doesn't exist or something like that 
  
          result = function1.Call()
  

  Expected results

  I should get the current simulation time using this function.

  Actual results

  Using the above code I get:

  **COMException**: Catastrophic failure (Exception from HRESULT: 0x8000FFFF (E_UNEXPECTED))
     at CANoe.ICAPL5.GetFunction(String Name)
  

  I've tried different variations of the code but didn't get anywhere.

  Is it possible to be a hardware problem? Should I do some settings in the CANoe Simulation?

  If you need more information, please ask me! Thanks in advance
• Could not import vxlapi: function 'xlCanReceive' not found

  I was trying to compile a code which interfaces with Cancasexl to send and receive signals from ECU. The library which I am using is python-can.

  But I am getting an error which says:

  Could not import vxlapi: function 'xlCanReceive' not found
  
  raise ImportError("The Vector API has not been loaded")
  ImportError: The Vector API has not been loaded
  

  I tried updating the CancaseXL drivers from the vector website thinking it might be a driver issue but still it shows up.

  def Can_receive_all(self):
    bus = can.interface.Bus(bustype='vector', channel=self.ch_list, bitrate=500000, app_name=self.can_app_name)
    try:
       while True:
          recv_msg = bus.recv()
          print(recv_msg)
        # if recv_msg is not None:
        # self.print_can_data(recv_msg)
     except Exception as ex:
       print(ex)
  

  I expected the Rx signals from the ECU but getting an error.
• Sending CAN-BUS messages from a raspberry pi webserver

  We are building a rover which should be controlled via web. It consist in a dozen arduino that split the jobs. One is dedicated to voice commands and text-to-speech, two keeps under control an array of ultrasonic sensors, and so on.

  In order to broadcast messages, so other elements can read and use whatever informations they need, we decided to use a can-bus system. The problem is located between the interface and the can-hat of the pi.

  Working: - Pi webserver with php built interface: reacheable and working. - Pi c-file executable called can_send that receives two parameters (id and message) and drives the can-hat. - Arduino can reader, a generic arduino that outputs on our PC serial monitor the can messages it receives. It works and by launching can_send on the Pi it gets the correct informations.

  Non working: - From the webserver, without refresh or pages in between, we should click a button and execute the can_send script.

  Our initial idea is something like: PHP interface -> button onclick -> javascript function -> PHP file that executes shell_exec.

  We are now struck here. Not knowing if we are digging our graves or a step close to the success.

  button on webinterface:

  <button style='width: 100px; height: 100px;background: url(./design/images/right.png)' onclick='cantxedx()' />

  javascript function (declared at the top of the webpage)

  function cantxedx() {
      var x = new XMLHttpRequest();
      x.open("GET", "../SCRIPTS/can_transmission.php?id=15&msg=001" + document.getElementbyId('myRangeThr'), true);
      x.send();
      return false;
  }
       </script> 
  

  can_transmission.php is the following:

       //can_transmission.php
  
       $TXmsgid= $_GET['id'];
       $TXmsg= $_GET['msg'];
  
       //formattazione stringa
  
       $wordsize = sizeof($TXmsg);
  
       if($wordsize<8)
       {
         while($wordsize<8)
         {
           $TXmsg= $TXmsg . "0";
           $wordsize = sizeof($TXmsg);
         }
       }
       if($wordsize>8)
       {
           //placeholder for building long messages
       }
       $TXstring= "sudo /var/www/html/SCRIPTS/c/can_send ".$TXmsgid." ".$TXmsg;
       $handle = fopen("log.txt", "a+");
             fwrite($handle, $TXstring);
       fclose($handle);
  
       shell_exec($TXstring);
  
  ?> 
  

  And a slider, which sets the value of the last part of the can-message

  <div align='center'>
      <p>THROTTLE</p>
  </div>
  <div class='slidecontainerv'>
      <input type='range' min='5' max='100' step='5' value='50' class='sliderv' id='myRangeThr' orient='vertical' width='500'>
  </div>
  <div align='center'>
      <p>Value: <span id='throttle'></span>%</p>
  </div>
  

  The idea is: when clicking the html button, the desired javascript function is executed.

  in this function we call a transmission file, passing the informations we need (id for the message, some informations relative to the button pressed in the first numbers of msg, and another value read from a slider)

  The transmission file drives the can-hat, and afterward the message is read and used by the arduino platoon.

  Something is not working somewhere between the button and the transmission file. When clicking a button nothing happens, not a new can-bus message nor a new log row.