4 Replies Latest reply on Jun 27, 2015 5:53 AM by salaideva

    Scrolling LCD

    salaideva

       Hi 

         

      i want to scroll the message in LCD display(16*2 lCd Hitachi ).

         

      Now i able to write message now i want to scroll that how to do it .

        • 1. Re: Scrolling LCD
          user_1377889

          Have a look into the Hitachi controller datasheet

             

          or

             

          probably would be better to manually (programatically) shift the output-string. Will be a good practice to get acquainted to C-strings, pointers and all that stuff.

             

           

             

          Bob

          • 2. Re: Scrolling LCD
            user_14586677

            One way, given you have a string in a buffer that is  len(strg) + 1,

               

            is to ( assume lcd is 16 char in a row ), so array is myString[ 17 ],

               

            addresses 0 - 16, 16 chars + one NULL (terminates string)

               

             

               

            1) Write string buffer to LCD

               

            2) Delay for the length of time between display writes, like 1 sec as example

               

            3) Move the characters in the string right 1 element, start by

               

            extracting 1 char, 14'th char (LCD column address 0 - 15) and write it back to buffer

               

            at address 15. Do this for 15 more, then fill myString[ 0 ] = ' ';

               

            4) Test for 16 shifts, if so exit loop

               

            5) goto 1

               

             

               

            This is a destructive write, eg the string buffer ultimately becomes all blanks.

               

             

               

            If you want the save the string copy it inot a temp buffer for the scroll operation use.

               

             

               

            Something like that.

               

             

               

            Regards, Dana.

            • 3. Re: Scrolling LCD
              salaideva

               Hi

                 

              what is purpose of of this command LCD_scrl_left$ right (datasheet) but when i implement this it doesn't works

              • 4. Re: Scrolling LCD
                user_14586677

                The actual LCD controller has a command set that will execute

                   

                certain functions, you can do this vs C code as I suggested.

                   

                 

                   

                Use LCD_Char_WriteControl() function in Creator LCD component

                   

                 

                   

                Regards, Dana.