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Serial LCD & Hyperterminal — Parallax Forums

Serial LCD & Hyperterminal

JmaniakJmaniak Posts: 3
edited 2006-11-30 04:30 in General Discussion
I recently started working with the 16x2 serial LCD ( http://www.parallax.com/detail.asp?product_id=27977 ). I've been looking through the provided documentation, which only explains how to control the device via BASIC stamp. However, I have this device attached to my laptop's serial port, and have provided +5V & ground appropriately. I was hoping to do a little coding in C to make a few little display programs, such as a weather ticker, e-mail notifier, etc.

To test my wiring, I tried sending data to the display via Hyperterminal, however, it only displays garbage, as if the data isn't being sent properly. Is it possible to communicate with this LCD via hyperterminal, and if so, which configuration settings should one use? (I figured the correct baud rate, 8 bits, no parity, 1 stop bit and no flow control would be correct)

Any thoughts or advice on communicating with this display via serial port would be appreciated. Thanks!

Comments

  • ForrestForrest Posts: 1,341
    edited 2006-11-18 22:38
    Your answer is shown on the Parallax LCD web page in your post!:

    "This device can be connected to a PC serial port using a MAX232 line driver. The circuit isn't supported by Parallax, but it's possible to make this connection with a few dollars of parts."

    RS232 voltage from a computer is -12V to +12V, while the serial LCD is expecting 0V to +5V. This voltage level can easily be converted by a MAX232 and 4 capacitors. Google MAX232 for more info from the datasheet
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2006-11-19 01:37
    Without the aforementioned circuit it is quite possible to damage the LCD Module as well.

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    Chris Savage
    Parallax Tech Support
  • JmaniakJmaniak Posts: 3
    edited 2006-11-20 05:49
    Ah, thank you both. I've got a couple MAX232s on the way, and I should be able to pick up some protoboard and caps this week [noparse]:)[/noparse]

    Anyway, once I've got things connected properly, I should be able to communicate with the device in the same manner I was attempting, or will I need to be using a different configuration?
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2006-11-20 17:23
    Hello,
    ·
    ·· With the Line Drivers (MAX232) installed you should be able to send standard serial data to it.· Take care.

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    Chris Savage
    Parallax Tech Support
  • JmaniakJmaniak Posts: 3
    edited 2006-11-30 04:30
    My Max232's finally came in today, so I wired up a little board and am fortunate enough to say that my LCD hasn't been damaged (that I know of). As of now it seems to function perfectly. Onto coding I go.

    Thank you for your help!
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