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Black box

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  • Black box

    We are initializing a pointer in the top right hand corner of our screen so that we can us it like a mouse for our screen. When the pointer is moved from that location there remains a black box. Any help on fixing this problem.

  • #2


    You don't indicate what you're using as a "pointer". Is it an image file from the uSD card, a text character, a user bitmapped character, or something else?

    Each of the "objects" above might cause the behavior that you describe under certain circumstances, but not knowing which, makes it difficult to know how to begin to answer you question.

    Posting your code (even pseudo code) would be very helpful for those that would try to help you.

    For example: Text characters have an Opaque/Transparent setting which might produce the effect you describe if set to Opaque rather than Transparent, but if you're not using text to render your pointer, this information is not of much help to you.

    Let us help by giving us more and detailed information about what you're trying to do and how you're trying to do it.

    Any technology, sufficiently developed, is indistinguishable from magic. A.C. Clark(RIP)

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    • #3

      Thank for the timely response. Here is the code we are using to initialize the pointer.
      BSP_USART_ByteWr(comm, '$'); //special command
      BSP_USART_ByteWr(comm, 'P'); //pointer parameter command
      BSP_USART_ByteWr(comm, 0x01); //show floating pointer
      BSP_USART_ByteWr(comm, 0x01); //solid
      BSP_USART_ByteWr(comm, 0x00); //small size
      BSP_USART_ByteWr(comm, 0x00); //color msb
      BSP_USART_ByteWr(comm, 0x00); //color lsb

      and when the pointer is moved these commands right off the data sheet are used

      spCmd : 24hex, $ascii
      cmd : 4Dhex, Mascii
      x : the horizontal screen position of pointer destination.
      y(msb:lsb) : the vertical screen position of pointer destination. 2 bytes.
      Let me know if there is anymore information needed for assistance.