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Character LCD

sanjay kumar3
Intellectual 530 points


Hi Frnds

I'm using 20x4 character LCD with Tiva129xnczad Development kit. When i switch ON power supply noting is displayed on LCD. but when i manually reset my kit Character get displayed on lcd. so manual reset is needed for Character LCD. 

  • 0
    TI__Guru**** 244400 points
    Hello Sanjay,

    Please publish the details on how you are connecting the Character LCD Panel pins to the DK-TM4C129, which Panel it is, what is meant by manual reset?

    Regards
    Amit
  • 0 in reply to Amit Ashara
    Guru 27285 points

    Hi Amit, uhm..
    [Magic bowle on]

    it sound simple, on init code is missing 1mS (or more) delay to wait for Hardware LCD reset... So at second attempt it work due it is out of hardware reset.
    Power off and cycle again do same problem never reappear till power isn't removed... [magic bowl rev 1.wip]

     I bet for a coffee but I fear we need exchange virtually.
    If this was on proper general problem area or more specialized too? ;)

  • 0 in reply to Roberto Romano
    TI__Guru**** 244400 points
    Hello Roberto

    You may be right (on the analysis and the coffee which will get cold on the way over), but having poster put up data as well like schematics or connections or even the panel being used along with software allows for analysis to be more precise. Your experience does make a difference in this case where you may have seen such an issue....

    And this is more of a habit the poster must get into ( http://e2e.ti.com/support/microcontrollers/tiva_arm/f/908/t/391803 )

    Regards
    Amit
  • 0 in reply to Amit Ashara
    Guru 27285 points

    Amit Ashara said:
    Your experience does make a difference in this case where you may have seen such an issue....

    Time machine on back to 1981: LCD display sometimes don't init at cold boot, all was exactly as data sheet recommended but it doesn't init... Patch 1: if after hardware init don't get ready flag try init again 3 time then shut down.. (it was a battery powered system Z80 based...) This appeared on early cold season and forever got  blocked on mid cold season: RC reset of LCD was ready in a few time at 25°C than when it was on external service. This was not specified on data sheet and after waiting 10mS instead of 1 it cured problem... That time I was without Logic analyzer and without emulator too but debugging code as user on machine (at cold season temperature too) firing debugging code by disk file then writing dump to "removable ram disk" (>TM<)  fixed it....

     It was era of floppy disk, 64K or less ram and compiler on single floppy... Before that I was using tape, both magnetic and paper (the blue one ;) and modem where big box running at 110/300 Baud or 1200/75 FSK based.

     .......

     Today emulator and (so called) low cost logic analyzer too are available and this happen not by external disturbance instead of lack thoroughly read data sheet.

  • 0 in reply to Roberto Romano
    Intellectual 530 points

    Hi Roberto Romano

    This Init solve my problem.You deserve not only coffee but snacks also.

    Thanks a  lot..........

  • 0 in reply to Roberto Romano
    Intellectual 530 points
    Hello Roberto Romano
    really a good experience!!!!!!!!!!!