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Real Time Clock Question — Parallax Forums

Real Time Clock Question

ArchiverArchiver Posts: 46,084
edited 2003-07-11 20:34 in General Discussion
Any one know of a real time clock chip that has an output variable of less than
1 second?
i.e. tenths/hundredths etc...

And how realistic is it to be able to use this with a BS2?

I'm looking at a data logger running at ideally 20Hz sampling about a dozen
bytes...

Cheers very much all,


Kev/.

[noparse][[/noparse]Non-text portions of this message have been removed]

Comments

  • ArchiverArchiver Posts: 46,084
    edited 2003-07-11 14:34
    Yep,

    The PCF8385 will do the trick.

    Down to 100th of a second timekeeping. Only catch is, it is I2C.
    The BS2 does not have I2C built in, but you can easily "Bit Bash"
    a solution.

    Visit
    http://www.lennard.net.nz/lennardelectronics/electronics/i2c.html
    #rtc for an idea on how to use the chip. I think I used a BS2sx for
    this example for some reason, but it also works OK on a BS2.

    Of course, I'd actually use a BS2pe if I were you, esp if you are
    serious on a Datalogging application. The BS2pe also has built
    in I2C Commands, therefore no Bit Bashing required.


    cheers,

    Ben,

    Windy (and friggin' cold) Wellington, NZ (winter has FINALLY
    arrived!)

    --- In basicstamps@yahoogroups.com, "Kev Pearce
    \(kevp.com\)" <email.me@k...> wrote:
    > Any one know of a real time clock chip that has an output
    variable of less than 1 second?
    > i.e. tenths/hundredths etc...
    >
    > And how realistic is it to be able to use this with a BS2?
    >
    > I'm looking at a data logger running at ideally 20Hz sampling
    about a dozen bytes...
    >
    > Cheers very much all,
    >
    >
    > Kev/.
    >
    > [noparse][[/noparse]Non-text portions of this message have been removed]
  • ArchiverArchiver Posts: 46,084
    edited 2003-07-11 14:55
    Hi,

    The philips PCF8583 (I2C bus) has hundredth of seconds. With a Bs2P with its
    builtin I2C commands
    You should be able to read this device several times per second.
    If seconds resolution is enough you can consider DS1207 (SPI) or DS1302
    (I2C).
    Also nice is a Xicor X1227 (I2C, seconds resolution, dual alarm, builtin 4K
    eeprom,
    1.75 seconds watchdog timer).

    Regards peter

    Oorspronkelijk bericht
    Van: Kev Pearce (kevp.com) [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=L-sDuKwIsXDUs4hwu3k6n0TwzFnzECqE9f3bLWDauIsZ1aln_VE1tIDBAO3YXRT6GuWhAixWftgi-Lo]email.me@k...[/url
    Verzonden: vrijdag 11 juli 2003 13:27
    Aan: basicstamps@yahoogroups.com
    Onderwerp: [noparse][[/noparse]basicstamps] Real Time Clock Question

    Any one know of a real time clock chip that has an output variable of less
    than 1 second?
    i.e. tenths/hundredths etc...

    And how realistic is it to be able to use this with a BS2?

    I'm looking at a data logger running at ideally 20Hz sampling about a dozen
    bytes...

    Cheers very much all,


    Kev/.

    [noparse][[/noparse]Non-text portions of this message have been removed]


    To UNSUBSCRIBE, just send mail to:
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  • ArchiverArchiver Posts: 46,084
    edited 2003-07-11 20:11
    Bit of a correction, the DS1302 isn't I2C, its three wire serial using its
    own sort of communications. Closer to SPI with a bi-directional I/O pin
    instead of MISO/MOSI.

    The DS1307 is real I2C
    Original Message
    From: "peter verkaik" <peterverkaik@b...>
    To: <basicstamps@yahoogroups.com>
    Sent: Friday, July 11, 2003 6:55 AM
    Subject: RE: [noparse][[/noparse]basicstamps] Real Time Clock Question


    > Hi,
    >
    > The philips PCF8583 (I2C bus) has hundredth of seconds. With a Bs2P with
    its
    > builtin I2C commands
    > You should be able to read this device several times per second.
    > If seconds resolution is enough you can consider DS1207 (SPI) or DS1302
    > (I2C).
    > Also nice is a Xicor X1227 (I2C, seconds resolution, dual alarm, builtin
    4K
    > eeprom,
    > 1.75 seconds watchdog timer).
    >
    > Regards peter
    >
    >
    >
    Oorspronkelijk bericht
    > Van: Kev Pearce (kevp.com) [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=oJJycOsNjypjDwF7tbZJOcL_alpkFPxbUsDpCk4fJ_NiG2eR1eBMwCadfnxJKxsCPvGpQ5F-yLoEeJ-c]email.me@k...[/url
    > Verzonden: vrijdag 11 juli 2003 13:27
    > Aan: basicstamps@yahoogroups.com
    > Onderwerp: [noparse][[/noparse]basicstamps] Real Time Clock Question
    >
    > Any one know of a real time clock chip that has an output variable of less
    > than 1 second?
    > i.e. tenths/hundredths etc...
    >
    > And how realistic is it to be able to use this with a BS2?
    >
    > I'm looking at a data logger running at ideally 20Hz sampling about a
    dozen
    > bytes...
    >
    > Cheers very much all,
    >
    >
    > Kev/.
    >
    > [noparse][[/noparse]Non-text portions of this message have been removed]
    >
    >
    > 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.
    >
    >
    > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
    >
    >
    >
    >
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    >
    >
  • ArchiverArchiver Posts: 46,084
    edited 2003-07-11 20:34
    Thanks for the correction.
    I took a look at the xicor website.
    The X1286 offers hundredth of a seconds plus 256K of builtin eeprom (I2C
    bus).
    No watchdog timer. The X1288 includes a watchdog timer.
    So Kev, you can have a single chip for both of your needs.
    http://www.xicor.com/folders/X1288.php

    regards peter
    Oorspronkelijk bericht
    Van: pm [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=veyrJMzt5Exe1ahL4ONIXto-4GNC6N9VzcbGU51mCCuweKRpmmhus-6putbvWJ1rpN85GUWAAaHP]pmeloy@s...[/url
    Verzonden: vrijdag 11 juli 2003 21:12
    Aan: basicstamps@yahoogroups.com
    Onderwerp: Re: [noparse][[/noparse]basicstamps] Real Time Clock Question

    Bit of a correction, the DS1302 isn't I2C, its three wire serial using its
    own sort of communications. Closer to SPI with a bi-directional I/O pin
    instead of MISO/MOSI.

    The DS1307 is real I2C
    Original Message
    From: "peter verkaik" <peterverkaik@b...>
    To: <basicstamps@yahoogroups.com>
    Sent: Friday, July 11, 2003 6:55 AM
    Subject: RE: [noparse][[/noparse]basicstamps] Real Time Clock Question


    > Hi,
    >
    > The philips PCF8583 (I2C bus) has hundredth of seconds. With a Bs2P with
    its
    > builtin I2C commands
    > You should be able to read this device several times per second.
    > If seconds resolution is enough you can consider DS1207 (SPI) or DS1302
    > (I2C).
    > Also nice is a Xicor X1227 (I2C, seconds resolution, dual alarm, builtin
    4K
    > eeprom,
    > 1.75 seconds watchdog timer).
    >
    > Regards peter
    >
    >
    >
    Oorspronkelijk bericht
    > Van: Kev Pearce (kevp.com) [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=2RGYSWR5oLJAwYkcg9xlf5_IZWXfAWDPKYZx8Y-uXSyDaWc5TJGvuR-TYcLRbz1X9Mdck9r22M5oag]email.me@k...[/url
    > Verzonden: vrijdag 11 juli 2003 13:27
    > Aan: basicstamps@yahoogroups.com
    > Onderwerp: [noparse][[/noparse]basicstamps] Real Time Clock Question
    >
    > Any one know of a real time clock chip that has an output variable of less
    > than 1 second?
    > i.e. tenths/hundredths etc...
    >
    > And how realistic is it to be able to use this with a BS2?
    >
    > I'm looking at a data logger running at ideally 20Hz sampling about a
    dozen
    > bytes...
    >
    > Cheers very much all,
    >
    >
    > Kev/.
    >
    > [noparse][[/noparse]Non-text portions of this message have been removed]
    >
    >
    > 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.
    >
    >
    > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
    >
    >
    >
    >
    > 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.
    >
    >
    > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
    >
    >


    To UNSUBSCRIBE, just send mail to:
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