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  • uLCD-43PCT touch detection problem

    Hello,

    I've received my screen few days ago and I was thinking there was a problem with touch detection.

    So I've made a simple application that request touch status (0x04), display it and wait 10ms in a loop. The result is that most of the time the release is not detected so the status stays on 3 instead of 2 then 0.

    Is there any parameter that I missed or is it a hardware problem that need a replacement ?

    thanks in advance.
    regards.

  • #2


    Check that you have the latest PmmC version, there were issues in an earlier version
    Mark

    Comment


    • #3


      Is it possible to do that without the programming cable ? (as our "buying team" only buy the display without the cable)....

      Comment


      • #4


        No, better have a chat with your buying team.

        In the meantime the Version command will tell you what version you have
        Mark

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        • #5


          The version command returns (values in decimal) :
          hardware_rev=16
          firmware_rev=33

          Comment


          • #6


            The is an issue with the uLCD-43PT at that level, but no known problem with the uLCD-43PCT.

            If you really have a PCT maybe you should double check your protocol and responses.
            Mark

            Comment


            • #7


              As I driving the screen from an arduino, I was using a library. To be sure the library was not in cause, I rewrite my application sending basic command and listening ACK.

              I have attached the code, please take a look at it to check if my command order is correct...

              PS: I notice that the change speed command always return NACK (it is why the code is in comment)... Attached files testTouchscreen.txt (2.7 KB)

              Comment


              • #8


                I think I have confirmation that there is an hardware problem....

                I have found a location on the screen where I can finger continuously (up and down) and quickly (2/3 touches by second) where the state is always correct (my test was 30s long). So the software seems not to be in cause.

                But if I move my finger a bit (1cm for exemple), since the first touch, the state stay at 3.

                Edit: One last information about my last test, the state was blocked at 3, the application was still active, and a moment later it displays 0.
                So maybe there is like a freeze of the touch and the LCD always returns 3.

                Comment


                • #9


                  Can you attach a photo of your display?

                  The reason the baud rate change does not work is that the response comes back (after a 100ms delay) at the new baud rate. (i.e. at the completion of the command, consistent with all other commands)
                  Mark

                  Comment


                  • #10


                    hi,

                    I've post a video that explain the problem. We can see that there is an area, upper left, where the touch works fine, and that the rest of the screen is more aleatory (the "touch status" is displayed on the upper left corner).

                    http://dl.free.fr/qHtmaO44i password 1234

                    Comment


                    • #11


                      Unfortunately that url asks for a userid and password
                      Mark

                      Comment


                      • #12


                        Yes, you can let the username empty and the password is 1234.

                        Comment


                        • #13


                          Hmm, nogo on IE, Firefox is a bit better but it tells me it is going to take 1 and a half hours.

                          Can you please just take a couple of photos of the screen and its 'attachments' (wires coming out of it)
                          Mark

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                          • #14


                            No pb...
                            The last photo shows that the "touch status" returns 3 even without touch... on most part of the screen

                            Attached files

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                            • #15


                              Yep, looks like a faulty touch panel.

                              Please contact support at 4dsystsms dot com dot au, referring to this thread
                              Mark

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