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  • D David Crow

    The first parameter is supposed to be a pointer.


    "The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

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    macmac38
    wrote on last edited by
    #9

    char *cReceivedChar; while(port.Read(cReceivedChar, 1, overlapped, &dwBytesRead)) Thanks, Mark

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    • M macmac38

      char *cReceivedChar; while(port.Read(cReceivedChar, 1, overlapped, &dwBytesRead)) Thanks, Mark

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      David Crow
      wrote on last edited by
      #10

      But then you'd have to allocate one byte of memory from the heap (i.e., cReceivedChar = new char). Why not just use this instead:

      char cReceivedChar;
      while(port.Read(&cReceivedChar, 1, overlapped, &dwBytesRead))
      ...


      "The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

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      • D David Crow

        But then you'd have to allocate one byte of memory from the heap (i.e., cReceivedChar = new char). Why not just use this instead:

        char cReceivedChar;
        while(port.Read(&cReceivedChar, 1, overlapped, &dwBytesRead))
        ...


        "The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

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        macmac38
        wrote on last edited by
        #11

        yep, it seems to be better to use a reference. with this procedure my string output is only "0.1922" remember incoming: 924.09,-4.06,676.26,0.156488,-0.653856,-0.714853,-0.192273 It looks like that the first values running through the digits in the dialog..mmh?? Is this so complicate to give out the full string? Thanks, Mark

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        • M macmac38

          yep, it seems to be better to use a reference. with this procedure my string output is only "0.1922" remember incoming: 924.09,-4.06,676.26,0.156488,-0.653856,-0.714853,-0.192273 It looks like that the first values running through the digits in the dialog..mmh?? Is this so complicate to give out the full string? Thanks, Mark

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          David Crow
          wrote on last edited by
          #12

          macmac38 wrote: yep, it seems to be better to use a reference. My example was not a reference. It was a pointer, exactly what the Read() method is expecting. Had it wanted a reference, the signature would look like:

          BOOL Read(void& lpBuf, ...);

          You mentioned that 924.09,-4.06,676.26,0.156488,-0.653856,-0.714853,-0.192273 is arriving at the serial port. How are you verifying this?


          "The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

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          • D David Crow

            macmac38 wrote: yep, it seems to be better to use a reference. My example was not a reference. It was a pointer, exactly what the Read() method is expecting. Had it wanted a reference, the signature would look like:

            BOOL Read(void& lpBuf, ...);

            You mentioned that 924.09,-4.06,676.26,0.156488,-0.653856,-0.714853,-0.192273 is arriving at the serial port. How are you verifying this?


            "The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

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            macmac38
            wrote on last edited by
            #13

            This is the position string from a robot arm and every time the same format. x,y,z shift and quaternion 1-4 I have to extract them later from the string in float variables Thanks, Mark

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            • M macmac38

              This is the position string from a robot arm and every time the same format. x,y,z shift and quaternion 1-4 I have to extract them later from the string in float variables Thanks, Mark

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              David Crow
              wrote on last edited by
              #14

              That's all well and good, but in your original post, you indicated that "This arrives at my serial port," implying that the data is indeed there. That's why I asked how you were verifying it. In the while loop that you are using to read the incoming data, how many times does the loop execute? After each call to Read(), what is the value of dwBytesRead? If the incoming data is always in the same format and is always less than X bytes, you might could use this instead:

              char received[X];
              port.Read(received, sizeof(received), overlapped, &dwBytesRead);
              received[dwBytesRead] = '\0';


              "The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

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              • D David Crow

                That's all well and good, but in your original post, you indicated that "This arrives at my serial port," implying that the data is indeed there. That's why I asked how you were verifying it. In the while loop that you are using to read the incoming data, how many times does the loop execute? After each call to Read(), what is the value of dwBytesRead? If the incoming data is always in the same format and is always less than X bytes, you might could use this instead:

                char received[X];
                port.Read(received, sizeof(received), overlapped, &dwBytesRead);
                received[dwBytesRead] = '\0';


                "The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

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                macmac38
                wrote on last edited by
                #15

                received[dwBytesRead] = '\0'; what does this line mean? I have "access violation" with this line. Thanks, Mark

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                • M macmac38

                  received[dwBytesRead] = '\0'; what does this line mean? I have "access violation" with this line. Thanks, Mark

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                  David Crow
                  wrote on last edited by
                  #16

                  macmac38 wrote: what does this line mean? It appends a \0 character to the end of the string. macmac38 wrote: I have "access violation" with this line. How big is the received array, and what is the value of dwBytesRead?


                  "The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

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                  • D David Crow

                    macmac38 wrote: what does this line mean? It appends a \0 character to the end of the string. macmac38 wrote: I have "access violation" with this line. How big is the received array, and what is the value of dwBytesRead?


                    "The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

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                    macmac38
                    wrote on last edited by
                    #17

                    char received[40]; port.Read(received, sizeof(received), overlapped, &dwBytesRead); TRACE( "Bytes read: %d",dwBytesRead); received[dwBytesRead] = '\0'; SetDlgItemText(IDC_SHIFT_X, received); Bytes read: 1Bytes read: -858993460Bytes read: -858993460Bytes read: -858993460 Thanks, Mark

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                    • M macmac38

                      char received[40]; port.Read(received, sizeof(received), overlapped, &dwBytesRead); TRACE( "Bytes read: %d",dwBytesRead); received[dwBytesRead] = '\0'; SetDlgItemText(IDC_SHIFT_X, received); Bytes read: 1Bytes read: -858993460Bytes read: -858993460Bytes read: -858993460 Thanks, Mark

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                      David Crow
                      wrote on last edited by
                      #18

                      macmac38 wrote: TRACE( "Bytes read: %d",dwBytesRead); Since dwBytesRead is a DWORD, you'll need to use the %lu format. Nonetheless, if received[] is only 40 bytes, trying to access the -858993460th position, or any value outside of 0-39, is obviously wrong. Check the return value of Read() beforehand. In your original post, you indicated that 58 characters were being sent to the serial port. You'll need room for that plus one more so received[] should be 59 not 40. This is not the root of the problem, however, but will eventually need to be addressed.


                      "The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

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                      • D David Crow

                        macmac38 wrote: TRACE( "Bytes read: %d",dwBytesRead); Since dwBytesRead is a DWORD, you'll need to use the %lu format. Nonetheless, if received[] is only 40 bytes, trying to access the -858993460th position, or any value outside of 0-39, is obviously wrong. Check the return value of Read() beforehand. In your original post, you indicated that 58 characters were being sent to the serial port. You'll need room for that plus one more so received[] should be 59 not 40. This is not the root of the problem, however, but will eventually need to be addressed.


                        "The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

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                        macmac38
                        wrote on last edited by
                        #19

                        char received[59]; port.Read(received, sizeof(received), overlapped, &dwBytesRead); TRACE( "Bytes read: %lu",dwBytesRead); received[dwBytesRead] = '\0'; SetDlgItemText(IDC_SHIFT_X, received); Bytes read: 1 I donn't know where's the problem? Normaly it seems easy..? Like to solve it today ;-) Thanks, Mark

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                        • M macmac38

                          char received[59]; port.Read(received, sizeof(received), overlapped, &dwBytesRead); TRACE( "Bytes read: %lu",dwBytesRead); received[dwBytesRead] = '\0'; SetDlgItemText(IDC_SHIFT_X, received); Bytes read: 1 I donn't know where's the problem? Normaly it seems easy..? Like to solve it today ;-) Thanks, Mark

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                          David Crow
                          wrote on last edited by
                          #20

                          macmac38 wrote: I donn't know where's the problem? Are you sure a problem exists? Maybe there was only one byte available to read.


                          "The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

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                          • D David Crow

                            macmac38 wrote: I donn't know where's the problem? Are you sure a problem exists? Maybe there was only one byte available to read.


                            "The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

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                            macmac38
                            wrote on last edited by
                            #21

                            But this Byte output like: j which means no character in it? But the full string is arriving.. if i don't use this line: received[dwBytesRead] = '\0'; the output is: -0.714853,-0.192273jjjjjjjjjjjjjjjjj Thanks, Mark

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                            • M macmac38

                              But this Byte output like: j which means no character in it? But the full string is arriving.. if i don't use this line: received[dwBytesRead] = '\0'; the output is: -0.714853,-0.192273jjjjjjjjjjjjjjjjj Thanks, Mark

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                              David Crow
                              wrote on last edited by
                              #22

                              macmac38 wrote: But the full string is arriving.. How are you verifying this claim? Whct class does the Read() method belong to? I'm curious if the fourth parameter is being used correctly. If more than one byte is being read, yet dwBytesRead equals 1, something is awfully wrong. It might also be the third parameter, but I've never used the OVERLAPPED structure before so I can't say for sure.


                              "The pointy end goes in the other man." - Antonio Banderas (Zorro, 1998)

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