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interfacing rtc ds1390 with pic using spi interface — Parallax Forums

interfacing rtc ds1390 with pic using spi interface

prajaktaprajakta Posts: 1
edited 2008-05-23 14:05 in General Discussion
hi,smhair.gif

I am·interfacing RTC ds1390 with 16f877a using spi interface
in datasheet of ds1390 pin 9 has a pull up resistor and its value is not given.
what should be its value and use?

Comments

  • David H.David H. Posts: 78
    edited 2008-05-23 13:26
    Usually a pull up resistor is used to keep the signal HIGH, until a LOW signal is sent. This keep the Input on pin 9 from floating and giving you unpredicable results. It makes the system more dependable and stable. For the value, you will get many opinions, but I like to use a 10K ohm resistor.
    Also, this should of been placed in another discussion forum, like the SANDBOX. This forum is for displaying projects that are completed.
    Good luck with the project.

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    David


    There are 10 types of people in this world,...
    Those that understand binary numbers, and those that don't!!!
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2008-05-23 14:05
    This thread is being moved from the Completed Projects Forum to the Sandbox Forum as it is off topic in the original forum.

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    Chris Savage
    Parallax Tech Support
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