Anyone have any experience with DS1305 RTC?

Discussion in 'The Projects Forum' started by sirch2, Jul 24, 2015.

  1. sirch2

    Thread Starter Well-Known Member

    Jan 21, 2013
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    I have made a little data logger with an atmega328 and a DS1305 Real Time Clock. The RTC is controlled by SPI and so uses the same pins as the programmer. I have been having all kinds of trouble programming the atmega and have come to the conclusion that the DS1305 sometimes gets into a condition where it is holding on to the SPI lines and so programming fails with weird errors (such as incorrect device signature).

    I know this is a long-shot but I was just wondering if anyone has experience of the DS3105 and knew a reliable sequence for enabling, setting/reading the time and disabling. Do I need a pull-up on the SS?
     
  2. nerdegutta

    Moderator

    Dec 15, 2009
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    I've tested an rtc. I think it was the 1305, and I used an Atmega 2560, and a 16x02 lcd.

    I made a supersimple circuit. First I programmed the Atmega to set the date time in the rtc, then I programmed the Atmega to read tve rtc, and display the time.

    I used 4K7 pull-up resistors on the commu ication lines.
     
  3. sirch2

    Thread Starter Well-Known Member

    Jan 21, 2013
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    Thanks nerdegutta, there seems to be some conflicting advice about pull-ups on SPI, some say they are not needed and others use them, I'll try a pull-up on the Slave Select and see how it goes.
     
  4. nerdegutta

    Moderator

    Dec 15, 2009
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    I just checked the RTC I used. It was a DS1307 - Sorry.

    But I'll guess the circuit is equal.

    Once I used a 24LC16b EEPROM with a PICAXE, and it needed the resistors.
     
  5. sirch2

    Thread Starter Well-Known Member

    Jan 21, 2013
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    The DS1307 is pretty similar I think, it doesn't have the "Alarm" outputs whereas the 1305 does, I guess the internal SPI circuitry is the same for both. Thanks for taking the time
     
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