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  • uLCD-OLED128 Board not responding

    I have been given a uLCD-OLED128 Board for a uni project and I suspect that there may be a hardware failure. I am trying to communicate with it via a PIC32 and I have installed the current limiting resistors on the TX and RX lines. There is no response from the board, it only powers up to the start screen and nothing else. I have been told that this unit has worked before but I am having trouble with comms. Is there any schematics for this board or can anyone offer some advise on what else to check.

  • #2


    What is displayed on the start screen (is it color or green)?

    Have you remembered to connect TX to RX and vice versa?

    Do you have a programming cable (or CE5 or MB5) you can connect to a PC with?
    Mark

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    • #3


      The start screen is in color

      Yes I have connected the Tx and Rx vice versa

      No I don't have a programming cable to connect to the PC with.

      I have made a RS232 to TTL circuit and tried communicating to the screen on its own via a terminal program sending the $55 command etc to see if that will work. Can I get away without the progamming cable or is this vital.

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      • #4


        The start screen is in color
        Good, so you appear to have SGC running

        Yes I have connected the Tx and Rx vice versa
        Good, so that looks right

        No I don't have a programming cable to connect to the PC with.

        I have made a RS232 to TTL circuit and tried communicating to the screen on its own via a terminal program sending the $55 command etc to see if that will work. Can I get away without the progamming cable or is this vital.
        If you don't want to change the PmmC you can get away without it.

        Of course it comes in handle for debugging problems such as yours.

        So what did you do with the RS232 to TTL circuit? Is it for a PC with a Serial port?

        What baud rate are you sending the U ($55) at?



        Loading...
        Mark

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        • #5


          Yes the circuit is to transmit data from a PC terminal through the RS232 port (using a USB to 232 Converter). I tried a few different baud rates from 9600 up to 115200. I kept sending the $55 command and then usually $45 to clear the screen but nothing changed on the screen.
          I have perfomed the same function on my PIC32 dev board just sending these commands out the serial port of the processor.

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          • #6


            Have you got the run jumper installed?

            If so, remove it.
            Mark

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            • #7


              I don't have the jumper installed.

              Comment


              • #8


                Try

                Powering up the display
                Wait until the splash appears
                Send a single U ($55)
                See if you get a response.


                The fact that you get the splash makes it seem very unlikely that there could be an issue (unless the previous user did something really stilly).

                Maybe you can post a picture of the display showing the splash?
                Mark

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                • #9


                  Sorry for late reply,
                  I thought I would take your advice and go back to basics. I went and got a scope from a friend to try and make sure everything was still working.

                  I have done what you have suggested and I do get a response from the display. For some reason I can not get my processor to interpret it and display it. I do see it on the scope but it is hard to decipher as the resolution on this scope wont let me see the full the message (I have no idea why it won't, very cheap scope I think). I have uploaded the photo of the flash. Anything else you think I have missed. Attached files

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                  • #10


                    Just to note as well, after I got the scope (after I took the photo) I didn't realise that the processor I am using is 3.3V so the resistors have been taken off the Tx and Rx lines. I thought this might have cured the problem but to no avail. The processor I am using is 5V tolerant on those lines and I thought it said it was 5V output.

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                    • #11


                      Please contact support at 4dsystems dot com dot au
                      Mark

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