Results 1 to 7 of 7

Thread: BS2 to EDE702 to LCD, Problem with LCD

  1. #1

    Default BS2 to EDE702 to LCD, Problem with LCD

    I am having problems with my LCD,

    I am new to this and I got an LCD, I am trying to hook it up to my BS2, it is not serial, I got it from DIGI-KEY and the vendor is Varatronics and the only numbers I see onˇthe PCB are 16265 R3, but from looking around I assume most LCD's have the same pin info. on the back there are 2 micro's with stickers over them, one is the HD44100FS, and theˇother is HD44780A00

    The LCD I have is 16x2 and its backlit. its 16 pins, the first two being the backlight, so 14 pins.
    when the power is enabled alls I get is the first line full of boxes?, I haven't seen it do much else, I bought a EDE702 Serial interface and still no difference, thought it would make it less confusing to figure out what was wrong. its nice to only have 3 wire interface asˇopposed toˇregular way.

    The EDE702 is working I can turn an LED on and off via the digital output on the EDE702 so I know the chip works with my serout command , but no change on the LCD.. I have been trying to figure it out. driving me nuts

    is there an easy way to know if the LCD works? like a test or something?

    can anyone help me out!

    Thanks in advance

    Tyson
    tysonstephen@home.com
    Last edited by ForumTools; 09-30-2010 at 11:56 AM. Reason: Forum Migration

  2. #2

    Default

    I think the backlight should be 15,16 and if you have it hooked up right and
    there are still
    boxes on line one then hook pin 4 to ground all should be fine

    > Tyson Stephen wrote:
    >
    > I am having problems with my LCD,
    >
    > I am new to this and I got an LCD, I am trying to hook it up to my BS2, it is
    not serial,
    > I got it from DIGI-KEY and the vendor is Varatronics and the only numbers I
    see on the PCB
    > are 16265 R3, but from looking around I assume most LCD's have the same pin
    info. on the
    > back there are 2 micro's with stickers over them, one is the HD44100FS, and
    the other is
    > HD44780A00
    >
    > The LCD I have is 16x2 and its backlit. its 16 pins, the first two being the
    backlight, so
    > 14 pins.
    > when the power is enabled alls I get is the first line full of boxes?, I
    haven't seen it
    > do much else, I bought a EDE702 Serial interface and still no difference,
    thought it would
    > make it less confusing to figure out what was wrong. its nice to only have 3
    wire
    > interface as opposed to regular way.
    >
    > The EDE702 is working I can turn an LED on and off via the digital output on
    the EDE702 so
    > I know the chip works with my serout command , but no change on the LCD.. I
    have been
    > trying to figure it out. driving me nuts
    >
    > is there an easy way to know if the LCD works? like a test or something?
    >
    > can anyone help me out!
    >
    > Thanks in advance
    >
    > Tyson
    > tysonstephen@h...
    >
    --------------------------------------------------------------------------------\
    ----------
    > eGroups.com Home: http://www.egroups.com/group/basicstamps
    > www.egroups.com - Simplifying group communications
    Last edited by ForumTools; 09-30-2010 at 11:56 AM. Reason: Forum Migration

  3. #3

    Default

    ----- Original Message -----
    From: LarryGaminde <lgaminde@t...>
    To: <basicstamps@egroups.com>
    Sent: Monday, March 27, 2000 1:54 PM
    Subject: [basicstamps] Re: BS2 to EDE702 to LCD, Problem with LCD


    > I think the backlight should be 15,16 and if you have it hooked up right
    and there are still
    > boxes on line one then hook pin 4 to ground all should be fine
    >

    well the backlight is the two pins before pin 1, pin 1 is marked. and I
    don't have any probs lighting the back. but I just can't get this thing to
    work. I have tried grounding pin 4 which is the RS and I still have a first
    line full of black boxes.



    > > Tyson Stephen wrote:
    > >
    > > I am having problems with my LCD,
    > >
    > > I am new to this and I got an LCD, I am trying to hook it up to my BS2,
    it is not serial,
    > > I got it from DIGI-KEY and the vendor is Varatronics and the only
    numbers I see on the PCB
    > > are 16265 R3, but from looking around I assume most LCD's have the same
    pin info. on the
    > > back there are 2 micro's with stickers over them, one is the HD44100FS,
    and the other is
    > > HD44780A00
    > >
    > > The LCD I have is 16x2 and its backlit. its 16 pins, the first two being
    the backlight, so
    > > 14 pins.
    > > when the power is enabled alls I get is the first line full of boxes?, I
    haven't seen it
    > > do much else, I bought a EDE702 Serial interface and still no
    difference, thought it would
    > > make it less confusing to figure out what was wrong. its nice to only
    have 3 wire
    > > interface as opposed to regular way.
    > >
    > > The EDE702 is working I can turn an LED on and off via the digital
    output on the EDE702 so
    > > I know the chip works with my serout command , but no change on the
    LCD.. I have been
    > > trying to figure it out. driving me nuts
    > >
    > > is there an easy way to know if the LCD works? like a test or something?
    > >
    > > can anyone help me out!
    > >
    > > Thanks in advance
    > >
    > > Tyson
    > > tysonstephen@h...
    >
    > --------------------------------------------------------------------------
    ----------------
    > > eGroups.com Home: http://www.egroups.com/group/basicstamps
    > > www.egroups.com - Simplifying group communications
    >
    > ------------------------------------------------------------------------
    > -- Check out your group's private Chat room
    > -- http://www.egroups.com/ChatPage?list...asicstamps&m=1
    >
    >
    Last edited by ForumTools; 09-30-2010 at 11:56 AM. Reason: Forum Migration

  4. #4

    Default

    At 02:02 PM 3/27/00 -0800, you wrote:
    >
    >well the backlight is the two pins before pin 1, pin 1 is marked. and I
    >don't have any probs lighting the back. but I just can't get this thing to
    >work. I have tried grounding pin 4 which is the RS and I still have a first
    >line full of black boxes.

    The RS pin needs to be connected to the EDE chip, not to ground.
    Doublecheck your wiring, with me it's always the wiring. The line of boxes
    means the LCD is being powered up without the controller being initialized.
    You have to tell_the_controller that it's a two line display. I have some
    control codes (and other LCD links) on my page at:

    http://www3.sympatico.ca/orthner/serialcd.html

    Cheers, Duncan
    Last edited by ForumTools; 09-30-2010 at 11:56 AM. Reason: Forum Migration

  5. #5

    Default

    ----- Original Message -----
    From: <orthner@s...>
    To: <basicstamps@egroups.com>
    Sent: Monday, March 27, 2000 2:33 PM
    Subject: [basicstamps] Re: BS2 to EDE702 to LCD, Problem with LCD


    > At 02:02 PM 3/27/00 -0800, you wrote:
    > >
    > >well the backlight is the two pins before pin 1, pin 1 is marked. and I
    > >don't have any probs lighting the back. but I just can't get this thing
    to
    > >work. I have tried grounding pin 4 which is the RS and I still have a
    first
    > >line full of black boxes.
    >
    > The RS pin needs to be connected to the EDE chip, not to ground.
    > Doublecheck your wiring, with me it's always the wiring. The line of boxes
    > means the LCD is being powered up without the controller being
    initialized.
    > You have to tell_the_controller that it's a two line display. I have some
    > control codes (and other LCD links) on my page at:
    >
    > http://www3.sympatico.ca/orthner/serialcd.html
    >
    > Cheers, Duncan
    >
    >

    Well I am still having problems so I will give you all a general Idea of
    what the circuit looks like


    I have pin 1, 2, 3, 4 of the EDE all to 5V, pin1 is the baud 2400=0,9600=1,
    and pin 2 is the polarity, 0=inverted, 1=standard. and pin 3 and pin 4 are 5
    volts

    pin 5 is connected to ground
    pin 6 is connected to the enable pin 6 on the LCD
    pin 7 is the RS pin 4 on the LCD
    pin 8 is the RW pin 5 on the LCD
    pin 9 NA
    pin 10 is connected to DB4 on the LCD pin 11
    pin 11 is connected to DB5 on the LCD pin 12
    pin 12 is connected to DB6 on the LCd pin 13
    pin 13 is connected to DB7 on the LCD pin 14
    pin 14 is connected to 5v which is connected to the LCD pin 2
    pin 15 and 16 are connected together with a 4mhz resonator
    pin 17 is the data line connected to pin 7 on the basic stamp 2
    pin 18 is the digital out, which I have an LED connected to, which works
    when I send the command
    serout 7, n9600,[$FE]
    serout 7, n9600,[%11111100] to turn the LED on and [%11111101 to turn it on.


    pin 1 on the LCD is connected to ground, pin 2 is connected to 5v and pin 3
    is connected to the POT.

    ok my basic stamp 2 code sorta goes like this

    N9600 con 84 ' Variable defination and 84 is what I got from the basic stamp
    manual for 9600 baud non inverted.

    lcd con 7 ' definition that the LCD data line is pin7

    loop:

    pause 200 ' to let the LCD initialize, never initializes though

    serout 7, n9600,[$FE]
    serout 7, n9600,[%000011]
    pause 10
    serout 7, n9600,[$FE]
    serout 7, n9600,[%000011]
    pause 10
    serout 7, n9600,[$FE]
    serout 7, n9600,[%000011]
    pause 10

    serout 7, n9600,[$FE]
    serout 7, n9600,[%000010]
    pause 10
    serout 7, n9600,[$FE]
    serout 7, n9600,[%000010]
    serout 7, n9600,[%001010]
    pause 10
    serout 7, n9600,[$FE]
    serout 7, n9600,[%001000]
    pause 10
    serout 7, n9600,[$FE]
    serout 7, n9600,[%000001]
    pause 10
    serout 7, n9600,[$FE]
    serout 7, n9600,[%000110]
    pause 10

    serout 7, n9600,[$FE]
    serout 7, n9600,[$01]

    pause 10


    pause 10

    serout LCD,N9600,["Hello LCD"] 'Supposed to print this on LCD'

    serout 7,n9600,[$FE] '=254 blank space?
    serout 7,n9600,[$C0] '=goes to second line
    pause 10

    serout 7,n9600,["This should be the second line"]



    This is where I got the info for initializing any HD44780 Controlled LCD

    When interface is 4-bits wide
    [Power ON]

    [ Wait more than 15ms ]
    [after Vdd rises to 4.5v]

    RS R/W DB7 DB6 DB5 DB4 Can't check BF before this instruction
    0 0 0 0 1 1 Function set (8-bit interface)

    [Wait more than]
    [ 4.1ms ]

    RS R/W DB7 DB6 DB5 DB4 Can't check BF before this instruction
    0 0 0 0 1 1 Function set (8-bit interface)

    [Wait more than]
    [ 100us ]

    RS R/W DB7 DB6 DB5 DB4 Can't check BF before this instruction
    0 0 0 0 1 1 Function set (8-bit interface)

    BF can be checked after the following
    instructions. When BF is not checked,
    the waiting time between instructions
    is longer than the execution time.
    (See Instruction set)

    RS R/W DB7 DB6 DB5 DB4
    0 0 0 0 1 0 Function set (to 4-bit interface)

    RS R/W DB7 DB6 DB5 DB4
    0 0 0 0 1 0
    0 0 N F * * Function set [4-bit Interface ]
    [Specify display lines]
    RS R/W DB7 DB6 DB5 DB4 [and character font ]
    0 0 0 0 0 0 These cannot be
    0 0 1 0 0 0 Display OFF changed afterwards

    RS R/W DB7 DB6 DB5 DB4
    0 0 0 0 0 0
    0 0 0 0 0 1 Display ON

    RS R/W DB7 DB6 DB5 DB4
    0 0 0 0 0 0
    0 0 0 1 I/D S entry mode set

    I am not sure I put this in my code correctly, since nothing works I have
    tried numerous combinations.

    if this is not clear email me and I will try to explain better....
    Last edited by ForumTools; 09-30-2010 at 11:56 AM. Reason: Forum Migration

  6. #6

    Default

    > pin 18 is the digital out, which I have an LED connected to, which works

    Your hardware connection looks good, and the fact that the EDE702 is
    receiving serial data and toggling the LED means that quite a few things are
    correct. Since you can see the top row of segments on, it sounds as if your
    contrast is O.K. but that the LCD is never being initialized. I noticed
    that you had code for initializing the LCD; this shouldn't be necessary, as
    the EDE702 handles all of this at powerup; you should only need to connect
    the EDE702 to the LCD, power it up, and all segments will be blank with the
    display initialized. You can write text without any further initialization
    on your part.

    Is the LCD module connector a 1x14 or 2x7 connector? Sometimes it's easy to
    miswire those 2x7 connectors and mistake the pin count. Also, I've seen a
    lot of connections from the EDE702 to the lower nibble of the LCD module; it
    needs to be to the upper. Doublecheck that as well. If you're still stuck,
    give me a call at (816) 257-9954 and we'll walk through the circuit pin by
    pin.

    Good luck,

    Todd Peterson
    E-Lab Digital Engineering, Inc.
    --Manufacturers of the EDExx IC Family--

    (816) 257-9954 FAX: (816) 257-9945
    http://www.elabinc.com
    Last edited by ForumTools; 09-30-2010 at 11:56 AM. Reason: Forum Migration

  7. #7

    Default

    ----- Original Message -----
    From: Todd Peterson <toddp@e...>
    To: <basicstamps@egroups.com>
    Sent: Tuesday, March 28, 2000 8:32 AM
    Subject: [basicstamps] Re: BS2 to EDE702 to LCD, Problem with LCD


    > > pin 18 is the digital out, which I have an LED connected to, which works
    >
    > Your hardware connection looks good, and the fact that the EDE702 is
    > receiving serial data and toggling the LED means that quite a few things
    are
    > correct. Since you can see the top row of segments on, it sounds as if
    your
    > contrast is O.K. but that the LCD is never being initialized. I noticed
    > that you had code for initializing the LCD; this shouldn't be necessary,
    as
    > the EDE702 handles all of this at powerup; you should only need to connect
    > the EDE702 to the LCD, power it up, and all segments will be blank with
    the
    > display initialized. You can write text without any further
    initialization
    > on your part.
    >
    > Is the LCD module connector a 1x14 or 2x7 connector? Sometimes it's easy
    to
    > miswire those 2x7 connectors and mistake the pin count. Also, I've seen a
    > lot of connections from the EDE702 to the lower nibble of the LCD module;
    it
    > needs to be to the upper. Doublecheck that as well. If you're still
    stuck,
    > give me a call at (816) 257-9954 and we'll walk through the circuit pin by
    > pin.
    >

    Yah I knew that the ede702 did all the initializing, but when it didn't work
    I just was trying everything... :)..
    its a 1-16 pin configuration so

    The vss is labeled pin 1
    0 0 0 0 0 0 0 0 0
    0 0 0 0 0 0 0
    db7 db6 db5 db4 db3 db2 db1 db0 E RW RS
    VEE VDD VSS + - for the back light

    Pardon my knwoledge gap, but what exactly do you mean be the lower nibble of
    the LCD? I think i have heard a few things like this but don't know what it
    means.

    Thanks a bunch I am learning a lot from this problem.

    -Tyson
    Last edited by ForumTools; 09-30-2010 at 11:56 AM. Reason: Forum Migration

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts