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3x4 keypad using encoder and bs2 — Parallax Forums

3x4 keypad using encoder and bs2

LEDREWLEDREW Posts: 4
edited 2007-12-03 15:02 in Learn with BlocklyProp
My friends and I are working on a keypad lock for a safe. We're having trouble getting started. We dont know what kind of encoder to use and how to use the keypad with the bs2. any suggestions?

Comments

  • Mike GreenMike Green Posts: 23,101
    edited 2007-11-29 15:39
    Look through the Nuts and Volts columns. There are several examples of the use of keypads.
    Here's the main page: www.parallax.com/Resources/NutsVoltsColumns/tabid/272/Default.aspx
  • Bruce BatesBruce Bates Posts: 3,045
    edited 2007-11-29 16:44
    LEDREW -

    Here is a keypad encoder that I've used often (link below). The datasheet can be downloaded from the same web page. One of the very nice aspects of it is that it provides a 1-wire serial output to minimize the number of Stamp pins necessary. Since it can operate at 2400 baud, it can even be used easily with a BS-1 or any BS-2 Stamp.

    The EDE1144 Keypad Encoder IC can be found here:
    http://www.allelectronics.com/cgi-bin/item/EDE-1144/search/KEYPAD_ENCODER_IC_.html

    The providers (E-Labs) are very helpful if you have any questions or problems. Here is a link to their web site: http://www.elabinc.com/

    Regards,

    Bruce Bates

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  • LEDREWLEDREW Posts: 4
    edited 2007-11-29 18:12
    thanks for the info bruce. you think this will work with a grayhill 4x3 83ac1 keypad?
  • LEDREWLEDREW Posts: 4
    edited 2007-11-29 18:16
    after checking that link out, i see that the encoder is for a 4x4 keypad. aw jeez!
  • Mike GreenMike Green Posts: 23,101
    edited 2007-11-29 18:28
    LEDREW,
    A 4 x 3 keypad is just a 4 x 4 keypad with one column never used. Just leave the column (or row) unconnected.
  • Bruce BatesBruce Bates Posts: 3,045
    edited 2007-11-29 18:34
    LEDREW -

    Take a look deeper into the datasheet on Page 6/7. It indicates that it can be used on smaller keypads as well, and discusses what you must do. Do remember the pull-down resistors as indicated in the schematic!

    Regards,

    Bruce Bates

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  • LEDREWLEDREW Posts: 4
    edited 2007-12-03 12:46
    thanks for the info bruce. youre a helpful guy. but unfortunatly, i wont be able to get that IC, as any order made wont come in until after the project is due! anyone know about alternate ways to hook up a 3x4 keypad to a LCD display without using the ebe1144?
  • Mike GreenMike Green Posts: 23,101
    edited 2007-12-03 15:02
    Again, look at the Nuts and Volts columns. A Stamp can do the encoding by itself.
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