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HELP!!! There are not enough inputs! — Parallax Forums

HELP!!! There are not enough inputs!

TCTC Posts: 1,019
edited 2010-08-09 16:06 in BASIC Stamp
I need to find a way to give the BS2 more inputs. The inputs will be hooked to buttons only. I would like to find something that can buffer the inputs ( If I Can) (if the buttons get pushed between checks). I am trying to save as many BS2 pins as I can. If there is a way I would like to find something that is synchronous so I can share clock and data pins of other devices that I am using.

Comments

  • eod_punkeod_punk Posts: 146
    edited 2010-08-08 06:52
    I'm pretty sure you can accomplish this using a parallel to serial buffer like the 74HC165.

    http://www.parallax.com/StoreSearchResults/tabid/768/List/0/SortField/4/ProductID/230/Default.aspx?txtSearch=serial+to+
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2010-08-08 08:55
    And if you are using a LCD, you can make double use of the data lines. There are several ways to get more inputs (or outputs)
  • rixterrixter Posts: 95
    edited 2010-08-08 16:50
    You may also be able to use an RCTIME circuit to do this.

    See this link:

    http://www.emesystems.com/BS2rct.htm#switches
  • TCTC Posts: 1,019
    edited 2010-08-08 17:54
    Edo punk- that is exactly what I was looking for. Thank you

    Loopy Byteloose- That is ironic, I am using a LCD. I am going to be sharing data lines just to keep my pin count low. Thank you

    Rixter- I was thinking of doing it that way. I have seen many remotes using a resistor network like that. But the only reason I do not think that it would be my best option for this project is the amount of time it takes to find out that there is no button pushed. Thank you

    I was looking around and I found this
    http://www.maxim-ic.com/datasheet/index.mvp/id/3365/CMP/BTDT

    I think it would work for what I need. My project requires the BS2 to control (4) dual-color LEDs, (6) buttons, (3)2 channel ADCs, a 4x16 LCD display, a digital pot (LCD contrast), (1) external input, and last but not least (1) external output. Please let me know if it might not work.

    Ever since my accident, I have been trying to come up with a project that will push my mental capability (lost some of my long term memory). So I am making a smart bench top power supply.

    So I would like to say to everyone, “I apologize if I ask questions like a newbie, but I have to start over” Thank you.
    TC
  • Ron CzapalaRon Czapala Posts: 2,418
    edited 2010-08-08 18:42
    There are some other I/O expander chips you might want to check out:

    You can use multiple chips for more pins...

    MCP23016 and MCP23017 (I2C)
    MCP23S17 (SPI)
  • TCTC Posts: 1,019
    edited 2010-08-08 19:08
    Ron Czapala- I like the MCP23S17, it seams easier than MAX6957 to interface to. And just like the MAX I can drive the LEDs off of it. Thank you
  • eod_punkeod_punk Posts: 146
    edited 2010-08-09 04:04
    Here's a clock Chris Savage made where he shared a bunch of clock and data lines. Might help jog your memory if you hit a road block.

    http://www.savagecircuits.com/forums/showthread.php?164-Binary-Digital-Clock
  • TCTC Posts: 1,019
    edited 2010-08-09 10:34
    Eod punk – that is perfect! I was planning on doing something like that with my project. Thank You
  • eod_punkeod_punk Posts: 146
    edited 2010-08-09 14:03
    Thank Chris he's the one that did all the work, all I did was provide a link. ;) But your welcome anyways. Let us know how well your project and memory turn out.
  • TCTC Posts: 1,019
    edited 2010-08-09 14:18
    I will, Thank you
  • Martin_HMartin_H Posts: 4,051
    edited 2010-08-09 16:06
    If you add an LCD backpack you can reduce your LCD to a single pin.
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