+ Post New Thread
Results 1 to 11 of 11
  1. #1
    Member level 1
    Points: 1,372, Level: 8

    Join Date
    Feb 2011
    Posts
    36
    Helped
    1 / 1
    Points
    1,372
    Level
    8

    PIC LCD Interface Problem (Hitachi HD44780)

    I hooked up a Hitachi HD44780 based 2x16 LCD with PIC18F2420. Now on the bootup, I should see boxes in the top row (Typical for a HD44780 based LCD). But what I see is 8 boxes in top row and 8 boxes in Bottom row.

    Is the LCD Blown or something else is wrong? I have attached a snapshot of LCD display


    Click image for larger version. 

Name:	photo (1).jpg 
Views:	32 
Size:	125.8 KB 
ID:	53699

    thanks for your time and help

    •   AltAdvertisement

        
       

  2. #2
    Advanced Member level 5
    Points: 33,613, Level: 44
    ckshivaram's Avatar
    Join Date
    Apr 2008
    Location
    villingen (Germany) / Bangalore
    Posts
    5,070
    Helped
    2158 / 2158
    Points
    33,613
    Level
    44
    Blog Entries
    1

    Re: PIC LCD Interface Problem (Hitachi HD44780)

    yes the LCD has gone bad..... try with other LCD, or execute an working code of LCD and test it............
    " It is so simple to be happy,
    but it is so difficult to be simple"



  3. #3
    Member level 2
    Points: 537, Level: 4

    Join Date
    Jan 2011
    Location
    gujrat,pakistan
    Posts
    44
    Helped
    4 / 4
    Points
    537
    Level
    4

    Re: PIC LCD Interface Problem (Hitachi HD44780)

    Quote Originally Posted by Tiwana6330 View Post
    I hooked up a Hitachi HD44780 based 2x16 LCD with PIC18F2420. Now on the bootup, I should see boxes in the top row (Typical for a HD44780 based LCD). But what I see is 8 boxes in top row and 8 boxes in Bottom row.

    Is the LCD Blown or something else is wrong? I have attached a snapshot of LCD display


    Click image for larger version. 

Name:	photo (1).jpg 
Views:	32 
Size:	125.8 KB 
ID:	53699

    thanks for your time and help
    sometimes it happens like this...but dnt be worried...you can use the Mikro c Sample programm of lcd...i hope it will work with you...
    "Be Professional............"



  4. #4
    Advanced Member level 1
    Points: 3,336, Level: 13

    Join Date
    May 2010
    Location
    Sri Lanka
    Posts
    403
    Helped
    121 / 121
    Points
    3,336
    Level
    13
    Blog Entries
    1

    Re: PIC LCD Interface Problem (Hitachi HD44780)

    Hi,

    Try with working code, it may be working...



  5. #5
    Full Member level 5
    Points: 3,560, Level: 14
    Achievements:
    7 years registered

    Join Date
    Feb 2007
    Location
    33 N, 73 E
    Posts
    255
    Helped
    37 / 37
    Points
    3,560
    Level
    14

    Re: PIC LCD Interface Problem (Hitachi HD44780)

    I have my doubt that LCD has gone bad.
    Apparently this is the type of LCD where you need to make Vo (contrast pin) as N.C (not connected)
    Then try with a working code, if you still have problems post the schematics and code and we'll look into it.



    •   AltAdvertisement

        
       

  6. #6
    Member level 1
    Points: 1,372, Level: 8

    Join Date
    Feb 2011
    Posts
    36
    Helped
    1 / 1
    Points
    1,372
    Level
    8

    Re: PIC LCD Interface Problem (Hitachi HD44780)

    ok..Now I have connected the LCD to a working code but somehow, as soon as the controller sends signals to initialize the LCD (I have a LED which Blinks Before going into Initialization), the PIC controller burns out......PIC starts taking over 1 Amp. I took the PIC out of the board and on Digital Multimeter (DMM) the VCC and VDD pins are short (Beep short). I thought that there is some problem in the circuit board so I replaced the controller and ran another blinking LED code and no problems (even though that the LCD was still connected but I was not sending any commands). Later I burned the LCD code on the PIC and as soon as it started sending initialization signals, it burned....

    Any clues? Thanks for help



  7. #7
    Banned
    Points: 340, Level: 3

    Join Date
    Dec 2010
    Posts
    66
    Helped
    10 / 10
    Points
    340
    Level
    3

    Re: PIC LCD Interface Problem (Hitachi HD44780)

    the internal CG and DD Ram has gone bad ... i prefer not to use LCD as it in internally getting short when the data is received by registers.



  8. #8
    Full Member level 4
    Points: 2,714, Level: 12
    Achievements:
    7 years registered
    g_shyam1682's Avatar
    Join Date
    Jan 2010
    Location
    Udaipur-Rajshan-India
    Posts
    206
    Helped
    53 / 53
    Points
    2,714
    Level
    12

    Re: PIC LCD Interface Problem (Hitachi HD44780)

    Hi Friend

    I think your LCD is burn out or bad .
    because i have experience that if LCD is OK and code is wrong.
    then only upper line of LCD has boxes and lower line is clean.

    But if both line has boxes then it is burn out or bad.

    change it with new one.

    Good Luck



  9. #9
    Advanced Member level 5
    Points: 33,613, Level: 44
    ckshivaram's Avatar
    Join Date
    Apr 2008
    Location
    villingen (Germany) / Bangalore
    Posts
    5,070
    Helped
    2158 / 2158
    Points
    33,613
    Level
    44
    Blog Entries
    1

    Re: PIC LCD Interface Problem (Hitachi HD44780)

    dont use this LCD,, or you will end up blowing all your controller in the stock..... This is a doubt i had in my first post...
    " It is so simple to be happy,
    but it is so difficult to be simple"



    •   AltAdvertisement

        
       

  10. #10
    Full Member level 5
    Points: 3,560, Level: 14
    Achievements:
    7 years registered

    Join Date
    Feb 2007
    Location
    33 N, 73 E
    Posts
    255
    Helped
    37 / 37
    Points
    3,560
    Level
    14

    Re: PIC LCD Interface Problem (Hitachi HD44780)

    Quote Originally Posted by abidr View Post
    I have my doubt that LCD has gone bad.
    I take my words back.....
    LCDs and VFDs are nasty things, I have seen many different behavior. The kind you mentioned above I saw this behavior in one of the 16x2 LCD that I used and I solved it the same way I mentioned above and that was to to N.C Vo pin.
    Only one reason for this behavior you might have connected the LCD supply in reverse.
    Last edited by abidr; 25th February 2011 at 14:20.



  11. #11
    Advanced Member level 2
    Points: 6,252, Level: 18

    Join Date
    May 2006
    Location
    India
    Posts
    644
    Helped
    123 / 123
    Points
    6,252
    Level
    18

    Re: PIC LCD Interface Problem (Hitachi HD44780)

    check your installation part of LCD, post your installation code, check the contrast control at pin 3 ( here not the issue for 8 digit)



--[[ ]]--