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Question about RTC — Parallax Forums

Question about RTC

ArchiverArchiver Posts: 46,084
edited 2004-06-10 03:37 in General Discussion
Hiya fellow stampers

I am looking for a RTC preferably Dallas series, doesn't have to be, that
has a I2C buss, time-date function, EEPROM, and most important alarm
interrupt outputs. really need 2 outputs. I found plenty out there but none
had an alarm interrupt output pin.

I need this so the BS2 could avoid polling the RTC and continue doing other
things until interrupted.

any ideas appreciated
Daryl

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2004-06-08 04:01
    I think this maybe what you need,I believe it only has one alarm
    output ,http://www.parallax.com/detail.asp?product_id=27962


    Stan






    --- In basicstamps@yahoogroups.com, Daryl Berryhill <djberry@h...>
    wrote:
    > Hiya fellow stampers
    >
    > I am looking for a RTC preferably Dallas series, doesn't have to
    be, that
    > has a I2C buss, time-date function, EEPROM, and most important
    alarm
    > interrupt outputs. really need 2 outputs. I found plenty out there
    but none
    > had an alarm interrupt output pin.
    >
    > I need this so the BS2 could avoid polling the RTC and continue
    doing other
    > things until interrupted.
    >
    > any ideas appreciated
    > Daryl
  • ArchiverArchiver Posts: 46,084
    edited 2004-06-08 04:42
    Check out the Xicor X1227 (http://www.xicor.com)
    This is a I2C rtc with builtin eeprom and supervisory circuitry (watchdog,
    power-on-reset),
    backup battery input, 2 alarm registers: the chip tests for 2 individual
    date/time
    alarms and sets a bit in the status register if matched. This status
    register must be polled
    but you don't need to compare alarm settings against current time.

    regards peter

    Original Message
    From: "Daryl Berryhill" <djberry@h...>
    To: <basicstamps@yahoogroups.com>
    Sent: Tuesday, June 08, 2004 4:46 AM
    Subject: [noparse][[/noparse]basicstamps] Question about RTC


    > Hiya fellow stampers
    >
    > I am looking for a RTC preferably Dallas series, doesn't have to be, that
    > has a I2C buss, time-date function, EEPROM, and most important alarm
    > interrupt outputs. really need 2 outputs. I found plenty out there but
    none
    > had an alarm interrupt output pin.
    >
    > I need this so the BS2 could avoid polling the RTC and continue doing
    other
    > things until interrupted.
    >
    > any ideas appreciated
    > Daryl
    >
    >
    >
    > To UNSUBSCRIBE, just send mail to:
    > basicstamps-unsubscribe@yahoogroups.com
    > from the same email address that you subscribed. Text in the Subject and
    Body of the message will be ignored.
    >
    > Yahoo! Groups Links
    >
    >
    >
    >
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  • ArchiverArchiver Posts: 46,084
    edited 2004-06-08 15:17
    The BS2 can't really be 'interrupted' in the technical
    sense of the term. If I understand you, though,
    you just want the BS2 to 'poll' a single "alarm pin",
    instead of having to read the current time again
    and again and again.

    If so, then the other posts have the solution
    for you.

    --- In basicstamps@yahoogroups.com, Daryl Berryhill <djberry@h...>
    wrote:
    > Hiya fellow stampers
    >
    > I am looking for a RTC preferably Dallas series, doesn't have to
    be, that
    > has a I2C buss, time-date function, EEPROM, and most important
    alarm
    > interrupt outputs. really need 2 outputs. I found plenty out there
    but none
    > had an alarm interrupt output pin.
    >
    > I need this so the BS2 could avoid polling the RTC and continue
    doing other
    > things until interrupted.
    >
    > any ideas appreciated
    > Daryl
  • ArchiverArchiver Posts: 46,084
    edited 2004-06-09 04:32
    the X1227 sounds like a perfect match. with one slight problem. the alarm
    pins need to be external. They will be connected to an I/O pin. when the
    time matches the alarm time it changes state the BS2 will know to read the
    register. also rather have a DIP than smt type.



    At 10:42 PM 6/7/2004, you wrote:
    >Check out the Xicor X1227 (http://www.xicor.com)
    >This is a I2C rtc with builtin eeprom and supervisory circuitry (watchdog,
    >power-on-reset),
    >backup battery input, 2 alarm registers: the chip tests for 2 individual
    >date/time
    >alarms and sets a bit in the status register if matched. This status
    >register must be polled
    >but you don't need to compare alarm settings against current time.
    >
    >regards peter
    >
    >
    Original Message
    >From: "Daryl Berryhill" <djberry@h...>
    >To: <basicstamps@yahoogroups.com>
    >Sent: Tuesday, June 08, 2004 4:46 AM
    >Subject: [noparse][[/noparse]basicstamps] Question about RTC
    >
    >
    > > Hiya fellow stampers
    > >
    > > I am looking for a RTC preferably Dallas series, doesn't have to be, that
    > > has a I2C buss, time-date function, EEPROM, and most important alarm
    > > interrupt outputs. really need 2 outputs. I found plenty out there but
    >none
    > > had an alarm interrupt output pin.
    > >
    > > I need this so the BS2 could avoid polling the RTC and continue doing
    >other
    > > things until interrupted.
    > >
    > > any ideas appreciated
    > > Daryl
    > >
    > >
    > >
    > > To UNSUBSCRIBE, just send mail to:
    > > basicstamps-unsubscribe@yahoogroups.com
    > > from the same email address that you subscribed. Text in the Subject and
    >Body of the message will be ignored.
    > >
    > > Yahoo! Groups Links
    > >
    > >
    > >
    > >
    > >
    > >
    >
    >
    >
    >
    >To UNSUBSCRIBE, just send mail to:
    > basicstamps-unsubscribe@yahoogroups.com
    >from the same email address that you subscribed. Text in the Subject and
    >Body of the message will be ignored.
    >
    >Yahoo! Groups Links
    >
    >
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2004-06-09 04:47
    Ok, you could do this then:
    use a digital alarm clock with dual outputs (relays) that you
    plug directly into the AC power wall socket.
    These clocks are not to expensive and have usually a small
    lcd display and advanced relay trigger functions.

    regards peter

    Original Message
    From: "Daryl Berryhill" <djberry@h...>
    To: <basicstamps@yahoogroups.com>
    Sent: Wednesday, June 09, 2004 5:32 AM
    Subject: Re: [noparse][[/noparse]basicstamps] Question about RTC


    > the X1227 sounds like a perfect match. with one slight problem. the alarm
    > pins need to be external. They will be connected to an I/O pin. when the
    > time matches the alarm time it changes state the BS2 will know to read the
    > register. also rather have a DIP than smt type.
    >
    >
    >
    > At 10:42 PM 6/7/2004, you wrote:
    > >Check out the Xicor X1227 (http://www.xicor.com)
    > >This is a I2C rtc with builtin eeprom and supervisory circuitry
    (watchdog,
    > >power-on-reset),
    > >backup battery input, 2 alarm registers: the chip tests for 2 individual
    > >date/time
    > >alarms and sets a bit in the status register if matched. This status
    > >register must be polled
    > >but you don't need to compare alarm settings against current time.
    > >
    > >regards peter
    > >
    > >
    Original Message
    > >From: "Daryl Berryhill" <djberry@h...>
    > >To: <basicstamps@yahoogroups.com>
    > >Sent: Tuesday, June 08, 2004 4:46 AM
    > >Subject: [noparse][[/noparse]basicstamps] Question about RTC
    > >
    > >
    > > > Hiya fellow stampers
    > > >
    > > > I am looking for a RTC preferably Dallas series, doesn't have to be,
    that
    > > > has a I2C buss, time-date function, EEPROM, and most important alarm
    > > > interrupt outputs. really need 2 outputs. I found plenty out there but
    > >none
    > > > had an alarm interrupt output pin.
    > > >
    > > > I need this so the BS2 could avoid polling the RTC and continue doing
    > >other
    > > > things until interrupted.
    > > >
    > > > any ideas appreciated
    > > > Daryl
    > > >
    > > >
    > > >
    > > > To UNSUBSCRIBE, just send mail to:
    > > > basicstamps-unsubscribe@yahoogroups.com
    > > > from the same email address that you subscribed. Text in the Subject
    and
    > >Body of the message will be ignored.
    > > >
    > > > Yahoo! Groups Links
    > > >
    > > >
    > > >
    > > >
    > > >
    > > >
    > >
    > >
    > >
    > >
    > >To UNSUBSCRIBE, just send mail to:
    > > basicstamps-unsubscribe@yahoogroups.com
    > >from the same email address that you subscribed. Text in the Subject and
    > >Body of the message will be ignored.
    > >
    > >Yahoo! Groups Links
    > >
    > >
    > >
    > >
    >
    >
    >
    > To UNSUBSCRIBE, just send mail to:
    > basicstamps-unsubscribe@yahoogroups.com
    > from the same email address that you subscribed. Text in the Subject and
    Body of the message will be ignored.
    >
    > Yahoo! Groups Links
    >
    >
    >
    >
    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2004-06-09 16:45
    --- In basicstamps@yahoogroups.com, Daryl Berryhill <djberry@h...>
    wrote:
    > Hiya fellow stampers
    >
    > I am looking for a RTC preferably Dallas series, doesn't have to
    be, that
    > has a I2C buss, time-date function, EEPROM, and most important
    alarm
    > interrupt outputs. really need 2 outputs. I found plenty out there
    but none
    > had an alarm interrupt output pin.
    >
    > I need this so the BS2 could avoid polling the RTC and continue
    doing other
    > things until interrupted.
    >
    > any ideas appreciated
    > Daryl

    Hi Daryl,

    it sounds like you want a programmable alarm and not just a clock
    chip.

    The BS2 is the thing that would look at the clock and then decide
    when to do something.

    A second micro (BS1 ?) could watch the clock and then create the
    alarm output, but that is adding a lot of complication to a simple
    circuit.

    Dave
  • ArchiverArchiver Posts: 46,084
    edited 2004-06-09 17:09
    Hi Daryl,

    The Philips PCF8593 is a very nice I2C RTC in an 8-pin DIP that has
    alarm registers and an interrupt pin. The interrupt pin is highly
    useful and programmable for one-time date/time alarm, weekday alarms
    or for a low frequency timer output. The PCF8583 is the same except
    that it also includes 240 bytes of general purpose RAM.

    I am not sure if Parallax has one of those available for sale. It
    does not come up in search.

    -- Tracy



    >--- In basicstamps@yahoogroups.com, Daryl Berryhill <djberry@h...>
    >wrote:
    >> Hiya fellow stampers
    >>
    >> I am looking for a RTC preferably Dallas series, doesn't have to
    >be, that
    >> has a I2C buss, time-date function, EEPROM, and most important
    >alarm
    >> interrupt outputs. really need 2 outputs. I found plenty out there
    >but none
    >> had an alarm interrupt output pin.
    >>
    >> I need this so the BS2 could avoid polling the RTC and continue
    >doing other
    >> things until interrupted.
    >>
    >> any ideas appreciated
    > > Daryl
    >
  • ArchiverArchiver Posts: 46,084
    edited 2004-06-10 03:37
    Tracy

    thanks for the info. this is Exactly what I was looking for. The extra ram
    is nice to. all I needed was 32 bytes. Unfortunately Digikey or mouser
    doesn't stock it. I was able to find it at www.arrow.com for
    2.78. Learned something I didn't know. This IC comes in the SOT-97-1
    package. which is the same thing as a DIP8 only smaller.

    Someone said, I think it was Dave, to use a BS1 as a secondary controller.
    excellent idea. guess I could use it as my main controller. since I'm using
    (2) PCF8574 I/O expanders and PCF8583 RTC/alarm/ram. with some custom I2C
    routines, the BS1 should fit the bill.

    The project I'm working on is just a simple 8 channel On/Off timer for
    outside lighting with inputs for 8 motion sensors. using 8 fused SSR's to
    handle the load. (because they were free) certain lights will come on for a
    length of time or when triggered by motion.

    oh yeah, Samsung mobile phone wall-wart charger makes a nice 5V power
    source. When I opened the case was surprised to find a small SMPS giving
    out 5V @ 1A. That was the best $1 spent at a thrift store. Yicks!! guess
    I'm getting a little O/T .. oh well..

    Daryl


    At 11:09 AM 6/9/2004, you wrote:
    >Hi Daryl,
    >
    >The Philips PCF8593 is a very nice I2C RTC in an 8-pin DIP that has
    >alarm registers and an interrupt pin. The interrupt pin is highly
    >useful and programmable for one-time date/time alarm, weekday alarms
    >or for a low frequency timer output. The PCF8583 is the same except
    >that it also includes 240 bytes of general purpose RAM.
    >
    >I am not sure if Parallax has one of those available for sale. It
    >does not come up in search.
    >
    > -- Tracy
    >
    >
    >
    > >--- In basicstamps@yahoogroups.com, Daryl Berryhill <djberry@h...>
    > >wrote:
    > >> Hiya fellow stampers
    > >>
    > >> I am looking for a RTC preferably Dallas series, doesn't have to
    > >be, that
    > >> has a I2C buss, time-date function, EEPROM, and most important
    > >alarm
    > >> interrupt outputs. really need 2 outputs. I found plenty out there
    > >but none
    > >> had an alarm interrupt output pin.
    > >>
    > >> I need this so the BS2 could avoid polling the RTC and continue
    > >doing other
    > >> things until interrupted.
    > >>
    > >> any ideas appreciated
    > > > Daryl
    > >
    >
    >
    >To UNSUBSCRIBE, just send mail to:
    > basicstamps-unsubscribe@yahoogroups.com
    >from the same email address that you subscribed. Text in the Subject and
    >Body of the message will be ignored.
    >
    >Yahoo! Groups Links
    >
    >
    >
    >
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