Connect with us

Real Time Pics

Discussion in 'Hobby Electronics' started by Robert, Jan 11, 2004.

  1. Robert

    Robert Guest

    With the Pics, I believe it is possible to purchase a chip that can display
    real time.

    Dose anybody know what this chip is or where it can be purchased.

    Thanks Robert
     
  2. cdb

    cdb Guest

    None of the current Pics have a RTC register such as that found in the
    Renesas (Hitachi) 3672.

    However, those Pics with a Timer1 register - 16F87x, 16F630, 16F80 and all
    the 18F series, do have the option of having an external 32.768KHz crystal
    as a time base for timer1 and from this an RTC can be fashioned.

    If your Pic doesn't have a Timer1 register, then there is an algorithm,
    using a 24bit register that will allow for an RTC with less jitter than that
    provided by an external crystal.

    I have a Water useage meter with combined Sprinkler controller that uses
    this Bresenham algorithm, and have had no problems as far as inacurracy is
    concerned.

    Of course another way is to 'borrow' the 50Hz mains frequency as the
    timebase.

    Colin
     
  3. Vermin

    Vermin Guest

    Wrong. The PIC16F7x7 range feature an RTC.

    V.
     
  4. Vermin

    Vermin Guest

    Actually you are right, Microchip misled me.

    The December 03 Microchip newsletter indicated that these chips had an
    on board RTC.

    Reading the datasheet shows that this is actually performed in
    software using TMR1!

    V.
     
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day

-