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Lcd help!!!! — Parallax Forums

Lcd help!!!!

ArchiverArchiver Posts: 46,084
edited 2001-10-19 14:23 in General Discussion
Ok gentlemen,

I am about to pull my hair out on a parallel LCD. This is my first time to
use one and I have serious problems.

I ordered a hitachi compatible parallel LCD from Allied and hooked it up.
I cannot get this thing to work and I cannot find any good code for just
simple testing. I found some on the stampworks experiment #11 and I cant
get it to work and all the rest that I found was for the 2P, which I am not
using.

Can anyone help me out here, I would like to use the 4bit mode, but will do
8 if that is what you have.

I just dont know where to start for now and am very frustrated!

TIA

Mark

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2001-10-16 22:07
    You can start by relaxing and checking your wiring. Then double-check your
    code. I've been using LCDs with BASIC Stamp since the BS1 and I can tell you
    for a fact that the StampWorks code does, in fact, work. If you're having
    problems, you've either miswired or done something bogus in the code.

    Go easy on yourself, it happens to the best of us. My bet is that you'll
    find the mistake (after you relax) and it will seem incredibly silly. Don't
    take anything for granted when you check your wiring and code. And do check
    with your vendor -- some cheapie LCDs require a negative voltage on the
    contrast pin....

    -- Jon Williams
    -- Applications Engineer, Parallax
    -- Author of StampWorks



    In a message dated 10/16/01 2:50:24 PM Central Daylight Time,
    madams@a... writes:


    > I am about to pull my hair out on a parallel LCD. This is my first time to
    > use one and I have serious problems.
    >
    > I ordered a hitachi compatible parallel LCD from Allied and hooked it up.
    > I cannot get this thing to work and I cannot find any good code for just
    > simple testing. I found some on the stampworks experiment #11 and I cant
    > get it to work and all the rest that I found was for the 2P, which I am not
    > using.
    >
    > Can anyone help me out here, I would like to use the 4bit mode, but will do
    > 8 if that is what you have.
    >
    > I just dont know where to start for now and am very frustrated!
    >




    [noparse][[/noparse]Non-text portions of this message have been removed]
  • ArchiverArchiver Posts: 46,084
    edited 2001-10-16 22:14
    Make sure you are using the correct data lines if you are in 4 bit mode. I
    made the mistake of sending data to 0 thru 3. The Optrex display I was
    interfacing needed input on data lines 4 thru 7.

    Original Message
    From: Mark Adams [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=TJrqy_cO5YSfw8GzuyXZ3MuPDzRdv2ooqGv3IA5INKeRSSfAeswWdBF3MHSoY4RSMVLe6Adw9irB]madams@a...[/url
    Sent: Tuesday, October 16, 2001 3:48 PM
    To: 'basicstamps@yahoogroups.com'
    Subject: [noparse][[/noparse]basicstamps] LCD HELP!!!!

    Ok gentlemen,

    I am about to pull my hair out on a parallel LCD. This is my first time to
    use one and I have serious problems.

    I ordered a hitachi compatible parallel LCD from Allied and hooked it up.
    I cannot get this thing to work and I cannot find any good code for just
    simple testing. I found some on the stampworks experiment #11 and I cant
    get it to work and all the rest that I found was for the 2P, which I am not
    using.

    Can anyone help me out here, I would like to use the 4bit mode, but will do
    8 if that is what you have.

    I just dont know where to start for now and am very frustrated!

    TIA

    Mark

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  • ArchiverArchiver Posts: 46,084
    edited 2001-10-16 23:17
    Use an EDE702. Well worth the $8. It's sells to work with a 1x16 or 2x16
    but I have it working with a 4x20 just fine. It takes serial in and even
    has an AUX digital pin you can set HIGH or LOW.

    http://www.j-com.net/lcd4x20.pdf


    James R. Parish
    J-Tech Internet Services
    J-Com Enterprises, Inc.

    Original Message
    From: Mark Adams [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=BsIIh4k5Tiqc7DOiBYIXyR5ud8lHlZLrxUJkadJ0A88i3sXqIpGSFTShpQj-kbwRcuLV281CZf3jHpfc6Q]madams@a...[/url
    Sent: Tuesday, October 16, 2001 3:48 PM
    To: 'basicstamps@yahoogroups.com'
    Subject: [noparse][[/noparse]basicstamps] LCD HELP!!!!

    Ok gentlemen,

    I am about to pull my hair out on a parallel LCD. This is my first time to
    use one and I have serious problems.

    I ordered a hitachi compatible parallel LCD from Allied and hooked it up.
    I cannot get this thing to work and I cannot find any good code for just
    simple testing. I found some on the stampworks experiment #11 and I cant
    get it to work and all the rest that I found was for the 2P, which I am not
    using.

    Can anyone help me out here, I would like to use the 4bit mode, but will do
    8 if that is what you have.

    I just dont know where to start for now and am very frustrated!

    TIA

    Mark

    To UNSUBSCRIBE, just send mail to:
    basicstamps-unsubscribe@yahoogroups.com
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  • ArchiverArchiver Posts: 46,084
    edited 2001-10-17 13:11
    The stampworks project does work (by my same experiences) but
    you must have it wored correctly, inlcuding the connection for
    contrast. (this one got me).

    Doug


    On 16 Oct 2001, at 14:48, Mark Adams wrote:

    > Ok gentlemen,
    >
    > I am about to pull my hair out on a parallel LCD. This is my first
    > time to use one and I have serious problems.
    >
    > I ordered a hitachi compatible parallel LCD from Allied and hooked it
    > up.
    > I cannot get this thing to work and I cannot find any good code for
    > just
    > simple testing. I found some on the stampworks experiment #11 and I
    > cant get it to work and all the rest that I found was for the 2P,
    > which I am not using.
    >
    > Can anyone help me out here, I would like to use the 4bit mode, but
    > will do 8 if that is what you have.
    >
    > I just dont know where to start for now and am very frustrated!
    >
    > TIA
    >
    > Mark
    >
    > To UNSUBSCRIBE, just send mail to:
    > basicstamps-unsubscribe@yahoogroups.com
    > from the same email address that you subscribed. Text in the Subject
    > and Body of the message will be ignored.
    >
    >
    > Your use of Yahoo! Groups is subject to
    > http://docs.yahoo.com/info/terms/
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2001-10-17 13:19
    Hi,

    I had just the same problem a few weeks ago. First, adjust the contrast pot
    to the point where you begin to see the character blocs. This stupid thing
    was my first problem. Second, if you use a breadboard, any bad contact will
    mess the communications. So, be sure to use wires that's not too thin.
    Hope this is not too late and will help...
    Phil.

    Original Message
    From: <jonwms@a...>
    To: <basicstamps@yahoogroups.com>
    Sent: Tuesday, October 16, 2001 11:07 PM
    Subject: Re: [noparse][[/noparse]basicstamps] LCD HELP!!!!


    > You can start by relaxing and checking your wiring. Then double-check
    your
    > code. I've been using LCDs with BASIC Stamp since the BS1 and I can tell
    you
    > for a fact that the StampWorks code does, in fact, work. If you're having
    > problems, you've either miswired or done something bogus in the code.
    >
    > Go easy on yourself, it happens to the best of us. My bet is that you'll
    > find the mistake (after you relax) and it will seem incredibly silly.
    Don't
    > take anything for granted when you check your wiring and code. And do
    check
    > with your vendor -- some cheapie LCDs require a negative voltage on the
    > contrast pin....
    >
    > -- Jon Williams
    > -- Applications Engineer, Parallax
    > -- Author of StampWorks
    >
    >
    >
    >
    > > I am about to pull my hair out on a parallel LCD. This is my first time
    to
    > > use one and I have serious problems.
    > >
    > > I ordered a hitachi compatible parallel LCD from Allied and hooked it
    up.
    > > I cannot get this thing to work and I cannot find any good code for just
    > > simple testing. I found some on the stampworks experiment #11 and I
    cant
    > > get it to work and all the rest that I found was for the 2P, which I am
    not
    > > using.
    > >
    > > Can anyone help me out here, I would like to use the 4bit mode, but will
    do
    > > 8 if that is what you have.
    > >
    > > I just dont know where to start for now and am very frustrated!
    > >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2001-10-17 16:19
    OK... still frustrated.

    I found the data sheets on my hitachi compatible device to find out that
    the pins were backwards... that burned up the first two stamps.

    Now I have the right connections and it still does not work. I have the
    unaltered stampworks code and all it displays is the first row of blocks
    (solid) Now a funny thing is happening. I programmed the stamp and it
    shows the blocks, but now it will not reprogram. Says it sees the stamp
    but it is not responding and to check the power supply. I plugged yet
    another one in, it programmed the first time and now nothing! THIS IS 4
    STAMPS that have burned up now.

    I am beginning to hate these LCD's and it would have been much cheaper on
    the serial unit. I dont have the contrast pot in the system, I just have
    it grounded along with the unused pins.

    I am at a total loss and need help.

    Thanks,

    Mark

    Original Message
    From: Philippe Derenne [noparse]/noparse]SMTP:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=qeEE6sIo15Om9sbKrHLoDSjyWS3PM0_0mRpUH1U3ulif0fwTphVjAZVB7cBF5_WtJamPyij5gZxD]derennep@s...[/url
    Sent: Wednesday, October 17, 2001 7:19 AM
    To: basicstamps@yahoogroups.com
    Subject: Re: [noparse][[/noparse]basicstamps] LCD HELP!!!!

    Hi,

    I had just the same problem a few weeks ago. First, adjust the contrast pot
    to the point where you begin to see the character blocs. This stupid thing
    was my first problem. Second, if you use a breadboard, any bad contact will
    mess the communications. So, be sure to use wires that's not too thin.
    Hope this is not too late and will help...
    Phil.

    Original Message
    From: <jonwms@a...>
    To: <basicstamps@yahoogroups.com>
    Sent: Tuesday, October 16, 2001 11:07 PM
    Subject: Re: [noparse][[/noparse]basicstamps] LCD HELP!!!!


    > You can start by relaxing and checking your wiring. Then double-check
    your
    > code. I've been using LCDs with BASIC Stamp since the BS1 and I can tell
    you
    > for a fact that the StampWorks code does, in fact, work. If you're
    having
    > problems, you've either miswired or done something bogus in the code.
    >
    > Go easy on yourself, it happens to the best of us. My bet is that you'll
    > find the mistake (after you relax) and it will seem incredibly silly.
    Don't
    > take anything for granted when you check your wiring and code. And do
    check
    > with your vendor -- some cheapie LCDs require a negative voltage on the
    > contrast pin....
    >
    > -- Jon Williams
    > -- Applications Engineer, Parallax
    > -- Author of StampWorks
    >
    >
    >
    >
    > > I am about to pull my hair out on a parallel LCD. This is my first
    time
    to
    > > use one and I have serious problems.
    > >
    > > I ordered a hitachi compatible parallel LCD from Allied and hooked it
    up.
    > > I cannot get this thing to work and I cannot find any good code for
    just
    > > simple testing. I found some on the stampworks experiment #11 and I
    cant
    > > get it to work and all the rest that I found was for the 2P, which I am
    not
    > > using.
    > >
    > > Can anyone help me out here, I would like to use the 4bit mode, but
    will
    do
    > > 8 if that is what you have.
    > >
    > > I just dont know where to start for now and am very frustrated!
    > >
    >



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  • ArchiverArchiver Posts: 46,084
    edited 2001-10-17 16:26
    Wow, four stamps, I haven't been following this thread, but I'd guess a pretty
    safe suggestion would be to STOP PLUGGING IN STAMPS.

    You can make a lot of head way understanding your LCD without using a stamp (or
    any kind of controller). You may want to read the linked EPE articles before
    you go any further with stamps.

    http://www.epemag.com/lcd1.pdf
    http://www.epemag.com/lcd2.pdf

    Good luck (and slow down).

    Kevin

    Mark Adams wrote:
    >
    > OK... still frustrated.
    >
    > I found the data sheets on my hitachi compatible device to find out that
    > the pins were backwards... that burned up the first two stamps.
    >
    > Now I have the right connections and it still does not work. I have the
    > unaltered stampworks code and all it displays is the first row of blocks
    > (solid) Now a funny thing is happening. I programmed the stamp and it
    > shows the blocks, but now it will not reprogram. Says it sees the stamp
    > but it is not responding and to check the power supply. I plugged yet
    > another one in, it programmed the first time and now nothing! THIS IS 4
    > STAMPS that have burned up now.
    >
    > I am beginning to hate these LCD's and it would have been much cheaper on
    > the serial unit. I dont have the contrast pot in the system, I just have
    > it grounded along with the unused pins.
    >
    > I am at a total loss and need help.
    >
    > Thanks,
    >
    > Mark
    >
    >
    Original Message
    > From: Philippe Derenne [noparse]/noparse]SMTP:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=oHw1eZ_BggyqOnk9n9TYbHNnSyK1bO-qLdC3I71_-DpMewIXN4t0aqW6HgqM-GeJf9ZOKXJGkfZy]derennep@s...[/url
    > Sent: Wednesday, October 17, 2001 7:19 AM
    > To: basicstamps@yahoogroups.com
    > Subject: Re: [noparse][[/noparse]basicstamps] LCD HELP!!!!
    >
    > Hi,
    >
    > I had just the same problem a few weeks ago. First, adjust the contrast pot
    > to the point where you begin to see the character blocs. This stupid thing
    > was my first problem. Second, if you use a breadboard, any bad contact will
    > mess the communications. So, be sure to use wires that's not too thin.
    > Hope this is not too late and will help...
    > Phil.
    >
    >
    Original Message
    > From: <jonwms@a...>
    > To: <basicstamps@yahoogroups.com>
    > Sent: Tuesday, October 16, 2001 11:07 PM
    > Subject: Re: [noparse][[/noparse]basicstamps] LCD HELP!!!!
    >
    > > You can start by relaxing and checking your wiring. Then double-check
    > your
    > > code. I've been using LCDs with BASIC Stamp since the BS1 and I can tell
    > you
    > > for a fact that the StampWorks code does, in fact, work. If you're
    > having
    > > problems, you've either miswired or done something bogus in the code.
    > >
    > > Go easy on yourself, it happens to the best of us. My bet is that you'll
    > > find the mistake (after you relax) and it will seem incredibly silly.
    > Don't
    > > take anything for granted when you check your wiring and code. And do
    > check
    > > with your vendor -- some cheapie LCDs require a negative voltage on the
    > > contrast pin....
    > >
    > > -- Jon Williams
    > > -- Applications Engineer, Parallax
    > > -- Author of StampWorks
    > >
    > >
    > >
    > >
    > > > I am about to pull my hair out on a parallel LCD. This is my first
    > time
    > to
    > > > use one and I have serious problems.
    > > >
    > > > I ordered a hitachi compatible parallel LCD from Allied and hooked it
    > up.
    > > > I cannot get this thing to work and I cannot find any good code for
    > just
    > > > simple testing. I found some on the stampworks experiment #11 and I
    > cant
    > > > get it to work and all the rest that I found was for the 2P, which I am
    > not
    > > > using.
    > > >
    > > > Can anyone help me out here, I would like to use the 4bit mode, but
    > will
    > do
    > > > 8 if that is what you have.
    > > >
    > > > I just dont know where to start for now and am very frustrated!
    > > >
    > >
    >
    > To UNSUBSCRIBE, just send mail to:
    > basicstamps-unsubscribe@yahoogroups.com
    > from the same email address that you subscribed. Text in the Subject and
    > Body of the message will be ignored.
    >
    > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
    >
    > To UNSUBSCRIBE, just send mail to:
    > basicstamps-unsubscribe@yahoogroups.com
    > from the same email address that you subscribed. Text in the Subject and Body
    of the message will be ignored.
    >
    >
    > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
  • ArchiverArchiver Posts: 46,084
    edited 2001-10-17 17:39
    In a message dated 10/17/01 10:27:39 AM Central Daylight Time,
    madams@a... writes:


    > I am beginning to hate these LCD's and it would have been much cheaper on
    > the serial unit. I dont have the contrast pot in the system, I just have
    >

    That might just be your problem -- I've found very few contrast inputs that
    would work well when grounded. Connect the contrast pin to the wiper of a
    10K pot that is connected between +5 and ground. With power to the display,
    you should be able to adjust the contrast pot so the character positions
    become visible.

    Once you get your other wiring sorted out, things will probably go much more
    smoothly.

    -- Jon Williams
    -- Parallax


    [noparse][[/noparse]Non-text portions of this message have been removed]
  • ArchiverArchiver Posts: 46,084
    edited 2001-10-17 17:44
    Hi Mark

    Mark : I have the unaltered stampworks code and all it displays is the first
    row of blocks (solid) Now a funny thing is happening. I programmed the
    stamp and it shows the blocks, but now it will not reprogram.

    John: Do you mean the program in PC just hang or what? How do you know it
    will not reprogram? What do you see when you run the code?

    Mark: Says it sees the stamp but it is not responding and to check the power
    supply.
    John: Whar carrier board are you using? Is it education board or something
    else? How do you power the stamp and LCD?

    Mark: I plugged yet another one in, it programmed the first time and now
    nothing! THIS IS 4 STAMPS that have burned up now.
    John: The previous 4 STAMPS may still be working. But how do you know those
    4 has been "burned up"?


    John: I am using the education board and the bread board built-in to test
    the LCD. Since I use the same power as in the education board to power the
    LCD, I feel more save about keeping my stamp and LCD. In some cases, I used
    resistors to protect the components, too.

    Relax.

    John Leung

    Original Message
    From: Mark Adams <madams@a...>
    To: <basicstamps@yahoogroups.com>
    Sent: Wednesday, October 17, 2001 11:19 PM
    Subject: RE: [noparse][[/noparse]basicstamps] LCD HELP!!!!


    > OK... still frustrated.
    >
    > I found the data sheets on my hitachi compatible device to find out that
    > the pins were backwards... that burned up the first two stamps.
    >
    > Now I have the right connections and it still does not work. I have the
    > unaltered stampworks code and all it displays is the first row of blocks
    > (solid) Now a funny thing is happening. I programmed the stamp and it
    > shows the blocks, but now it will not reprogram. Says it sees the stamp
    > but it is not responding and to check the power supply. I plugged yet
    > another one in, it programmed the first time and now nothing! THIS IS 4
    > STAMPS that have burned up now.
    >
    > I am beginning to hate these LCD's and it would have been much cheaper on
    > the serial unit. I dont have the contrast pot in the system, I just have
    > it grounded along with the unused pins.
    >
    > I am at a total loss and need help.
    >
    > Thanks,
    >
    > Mark
  • ArchiverArchiver Posts: 46,084
    edited 2001-10-18 01:35
    I had similar frustrations untill I grounded all the unused data
    input pins on the LED. p0-p3. Some programs do not document this as a
    requirement for the parallel LCD's using 4 bit mode. Give it a try.
    It worked for me.

    --- In basicstamps@y..., Mark Adams <madams@a...> wrote:
    > Ok gentlemen,
    >
    > I am about to pull my hair out on a parallel LCD. This is my first
    time to
    > use one and I have serious problems.
    >
    > I ordered a hitachi compatible parallel LCD from Allied and hooked
    it up.
    > I cannot get this thing to work and I cannot find any good code
    for just
    > simple testing. I found some on the stampworks experiment #11 and
    I cant
    > get it to work and all the rest that I found was for the 2P, which
    I am not
    > using.
    >
    > Can anyone help me out here, I would like to use the 4bit mode, but
    will do
    > 8 if that is what you have.
    >
    > I just dont know where to start for now and am very frustrated!
    >
    > TIA
    >
    > Mark
  • ArchiverArchiver Posts: 46,084
    edited 2001-10-19 14:23
    Gentlemen,

    I just wanted to let yall know what happened so you dont think I am a
    complete idiot.

    I recieved the file that was sent and read through it on using the
    intelligent displays, so I built up the circuit and tested my LCD's. It
    worked properly and exactly as I would have expected it.

    Ok, here is what happened. I have a large three section protoboard. I
    have an active circuit on the left bank that is working properly. My LCD
    problems were in the middle section and I built the working LCD test
    circuit in the right section. Whenever I changed the LCD to the middle
    circuit, it would burn it up and take out the stamp... so what it boiled
    down to is that there was a problem (probably a short between some internal
    connections) with the protoboard and it has since been replaced and all is
    working well.

    Thank you to all for their patience and help, and I am sorry for getting so
    frustrated.

    Thanks again.

    Mark

    Original Message
    From: John Leung [noparse]/noparse]SMTP:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=nlwEoT3CWIne5XwVpzGKjZa4Nv_9HgvAZrRC4UzedPXCP7C3l_XoJ5ycjbGlObA_OVU2_ijN8zB1dSXjiQ]jleung00@n...[/url
    Sent: Wednesday, October 17, 2001 11:44 AM
    To: basicstamps@yahoogroups.com
    Subject: Re: [noparse][[/noparse]basicstamps] LCD HELP!!!!

    Hi Mark

    Mark : I have the unaltered stampworks code and all it displays is the
    first
    row of blocks (solid) Now a funny thing is happening. I programmed the
    stamp and it shows the blocks, but now it will not reprogram.

    John: Do you mean the program in PC just hang or what? How do you know it
    will not reprogram? What do you see when you run the code?

    Mark: Says it sees the stamp but it is not responding and to check the
    power
    supply.
    John: Whar carrier board are you using? Is it education board or something
    else? How do you power the stamp and LCD?

    Mark: I plugged yet another one in, it programmed the first time and now
    nothing! THIS IS 4 STAMPS that have burned up now.
    John: The previous 4 STAMPS may still be working. But how do you know those
    4 has been "burned up"?


    John: I am using the education board and the bread board built-in to test
    the LCD. Since I use the same power as in the education board to power the
    LCD, I feel more save about keeping my stamp and LCD. In some cases, I used
    resistors to protect the components, too.

    Relax.

    John Leung

    Original Message
    From: Mark Adams <madams@a...>
    To: <basicstamps@yahoogroups.com>
    Sent: Wednesday, October 17, 2001 11:19 PM
    Subject: RE: [noparse][[/noparse]basicstamps] LCD HELP!!!!


    > OK... still frustrated.
    >
    > I found the data sheets on my hitachi compatible device to find out that
    > the pins were backwards... that burned up the first two stamps.
    >
    > Now I have the right connections and it still does not work. I have the
    > unaltered stampworks code and all it displays is the first row of blocks
    > (solid) Now a funny thing is happening. I programmed the stamp and it
    > shows the blocks, but now it will not reprogram. Says it sees the stamp
    > but it is not responding and to check the power supply. I plugged yet
    > another one in, it programmed the first time and now nothing! THIS IS 4
    > STAMPS that have burned up now.
    >
    > I am beginning to hate these LCD's and it would have been much cheaper on
    > the serial unit. I dont have the contrast pot in the system, I just have
    > it grounded along with the unused pins.
    >
    > I am at a total loss and need help.
    >
    > Thanks,
    >
    > Mark


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    basicstamps-unsubscribe@yahoogroups.com
    from the same email address that you subscribed. Text in the Subject and
    Body of the message will be ignored.


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