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Lcd terminal appmod problems! — Parallax Forums

Lcd terminal appmod problems!

kierakiera Posts: 5
edited 2006-11-20 21:43 in BASIC Stamp
hi,
my project is continuing to be quite difficult as I attempt to hook up a dual-axis accelerometer with a basic stamp 2 & LCD screen. currently, the accelerometer is working but the LCD (LCD Terminal AppMod Stock#: 29121 Category: Accessories-LCD [url=http:// http://www.parallax.com/detail.asp?product_id=29121 ] http://www.parallax.com/detail.asp?product_id=29121 [/url]) is not displaying anything. So far, I have tried to hook it up in various ways to the stamp & attempted the excercise code, but nothing shows up on the screen. Even when the contrast is adjusted. I've tried multiple ways of wiring it as well, according to different schematics found, but all yield no result. Different versions I tried was only hooking up the first three pins to the basic stamp, and the power & ground, and then I tried hooking almost all the wires from the LCD to the stamp. I also tried reversing the wiring in case I was inverting it by accident). I was also careful in making sure the coding correlated to what I was doing so this shouldn't be the problem..If anyone could help me out in getting this thing to work I would be thrilled.
thanks,
kiera.

ps. all the different ways I tried to hook it up are online at the link below:
http://a.parsons.edu/~kiera/thesis/konstruct/konstruct2.html

Comments

  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2006-11-06 00:55
    Kiera,
    ·
    ·· The LCD AppMod is designed to plug into an AppMod socket.· This automatically connects the proper lines to where they need to go.· Are you not using an AppMod connector on your board?

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    Chris Savage
    Parallax Tech Support
  • kierakiera Posts: 5
    edited 2006-11-06 01:05
    Chris,
    Thank you for your replies/help. No I'm not using an AppMod socket. I've just been looking for it online, and am wondering if it's that black rectangular thing that has all the holes in it? The LCD came with a connector with a lot of pins which I'm assuming has to be connected to the LCD & then to the AppMod socket? Is it possible to buy an AppMod socket or do I really have to wire everything into a pre-made board/kit? & then connect it?
    Thanks again,
    kiera.
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2006-11-06 01:32
    Kiera,
    ·
    ·· The LCD AppMod is designed to plug into an AppMod socket, which is a socket on the Board Of Education, as well as a few other development boards we sell.· What board are you using?

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    Chris Savage
    Parallax Tech Support
  • kierakiera Posts: 5
    edited 2006-11-06 01:52
    I'm just using a regular breadboard where I've put on a basic stamp...So basically there is no way to hardwire the LCD AppMod onto the breadboard I'm currently using?
    thanks again,
    kiera.
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2006-11-06 05:37
    Kiera,
    ·
    ·· The pins cannot properly plug into a breadboard.· You would need a special adapter to plug it into one.· Without it the pins will be shorted together, since the two columns would be on the same set of rows, electrically.

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    Chris Savage
    Parallax Tech Support
  • kierakiera Posts: 5
    edited 2006-11-06 15:50
    hmm. thank you for that.. one last question then: what sort of LCD would you recommend to buy if i just want to plug it into my soderless breadboard & connect it to my basic stamp2 & to display info from my accelerometer? the ones i was looking at were:

    -the 112 x 16 Serial Graphic VFD Display, Stock#: 27970 Category: Accessories-LCD
    [url=http:// http://www.parallax.com/detail.asp?product_id=27970 ] http://www.parallax.com/detail.asp?product_id=27970 [/url]

    -Parallax 2x16 Serial LCD (Backlit), Stock#: 27977 Category: Accessories-LCD
    [url=http:// http://www.parallax.com/detail.asp?product_id=27977 ] http://www.parallax.com/detail.asp?product_id=27977 [/url]

    -2x16 Parallel LCD, Stock#: 603-00006 Category: Accessories-LCD
    [url=http:// http://www.parallax.com/detail.asp?product_id=603-00006 ] http://www.parallax.com/detail.asp?product_id=603-00006 [/url]

    is there anything missing from any of those LCDs that i would need??
    thanks,
    kiera.
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2006-11-06 16:51
    Kiera,
    ·
    ·· Any of these displays would work, since they’re breadboard friendly.· Obviously the Parallel unit would take more I/O pins to operate.

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    Chris Savage
    Parallax Tech Support
  • RDL2004RDL2004 Posts: 2,554
    edited 2006-11-06 23:45
    It seems the link you posted has two "http://" in it so it doesn't work. I did go to the correct page, and from the pictures it seems like you should have been able to get it to work.

    The appmod LCD wasn't plugged directly into the breadboard, there were wires running between the LCD connector and the Stamp on the breadboard.

    The appmod connector is just an extra, standardized, way to connect to the Stamp's pins (plus there are 2 Vss, a Vin and a Vdd connection).

    I did not actually check your wiring in the photos, but assuming you make the correct connections (including power and ground) to the LCD it should work.

    a.parsons.edu/~kiera/thesis/konstruct/konstruct2.html

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    - Rick
  • Tom FTom F Posts: 59
    edited 2006-11-17 18:36
    I didn't do my homework. I bought an LCD Terminal AppMod but now see that it won't work with the Homework board. Is that correct?
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2006-11-17 20:48
    Tom,
    ·
    ·· That is correct…The AppMod is designed to plug into an AppMod socket, something the H/W Board does not have.

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    Chris Savage
    Parallax Tech Support
  • Tom FTom F Posts: 59
    edited 2006-11-17 21:39
    Would the Parallax Serial LCD (#27966) work with the H/W board, Chris?
  • Tom FTom F Posts: 59
    edited 2006-11-17 21:47
    Follow-up question (having read some more!): Since the Serial LCD requires 20-80ma and an external power supply, could you suggest how to do that?

    I can get a 5v supply and wire it up directly to the GND and 5V pins on the LCD. Is it important that the power supply GND also be attached to Vdd on the board?

    And, while we're at it, what's the best way to use the external supply to supply power to the H/W board itself? I can easily run the external power in through the 9V battery connector. Can the board use 5V that way?
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2006-11-17 23:41
    Tom,
    ·
    ·· Yes, the Serial LCD, in fact, most other devices work well with the H/W Board.· It just doesn’t have the AppMod Socket, so anything AppMod is going to be difficult to interface.· As for external power supplies.· If you power something from an external power supply, the device still needs a common ground with the H/W Board.· That is Vss, not Vdd!· That is important.· Also, use of the on-board regulator depends on which revision of the H/W Board you have.· Rev C can drive the Serial LCD direct.· I hope this helps.· Take care.

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    Chris Savage
    Parallax Tech Support
  • Tom FTom F Posts: 59
    edited 2006-11-20 19:03
    Darn. I'm running Rev B of the board. So that simply means that unless I want to add a regulator, I need to drive the LCD with the 5 volt. No big deal. Can I drive the H/W board with that same 5 volts, through the battery connector?

    Will I be able to do the Industrial Control & Sensor curricula with the H/W board?

    Sorry for the noob questions, Chris.

    I'm having a ball with WAM. Your written materials are absolutely superb!!!

    By the way, what happened to selling WAM through Radio Shack? Has that channel gone away?

    Thanks again!
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2006-11-20 21:11
    Tom,
    ·
    ·· You can drive everything from a 5V supply, but I wouldn’t connect it to the battery terminals.· Instead connect it to the Vdd lines.· The battery terminals require at least 5.5V to regulate properly.· If you use Vdd, do not connect anything to the battery snaps.·
    ·
    ·· As for WAM, I believe Radio Shack is still carrying that.· It was the BOE-Bot they discontinued.· You should still be able to pick up a WAM kit at most stores.· I hope this helps.· Take care.

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    Chris Savage
    Parallax Tech Support
  • Tom FTom F Posts: 59
    edited 2006-11-20 21:43
    Will I be able to do the Industrial Control & Sensor curricula with the H/W board?
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