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RCTIME and COUNT through an Analog Switch — Parallax Forums

RCTIME and COUNT through an Analog Switch

G McMurryG McMurry Posts: 134
edited 2010-02-19 18:51 in BASIC Stamp
Has anyone been successful expanding the IO pins of a Basic Stamp through an analog switch? I have several voltages I want to monitor using RCTIME and was considering the MAX4617 to expand my Basic Stamp..

THANKS

Greg

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Comments

  • Mike GreenMike Green Posts: 23,101
    edited 2010-02-19 17:49
    Using a MAX4617 should work. You need to respect the voltage limits of the MAX4617.

    You may do better with a multi-channel SPI ADC like the MCP3208 because it only needs 3 I/O pins to work with the Stamp (Din and Dout are connected together).
  • G McMurryG McMurry Posts: 134
    edited 2010-02-19 18:20
    I have already designed a board using an ADC but the conditioning I need for each input started making me look at OpAmps and additional voltages on each channel and that got pretty hungry with board space.

    The precision I get with RCTIME is fine for my application...

    I see what you are talking about with the voltage limit of the MAX4617. I will see if I can find another device.

    Another idea might be just to use the 2p 40 pin version. Then I might have enough IO with out expanding...

    Thanks!

    Greg

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    AUTOMATE EVERYTHING
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  • Tracy AllenTracy Allen Posts: 6,664
    edited 2010-02-19 18:51
    The original CMOS family has much wider voltage range. Applicable devices would be the
    CD4066, quad analog switch
    CD4051, single 8 to 1 analog mux
    CD4052, dual 4 to 1 analog mux
    CD405, triple 2 to 1 analog mux

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    Tracy Allen
    www.emesystems.com
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