Urgent assistance on project

Discussion in 'Embedded Systems and Microcontrollers' started by mtmaidoki, Jul 5, 2011.

  1. mtmaidoki

    Thread Starter New Member

    Jul 5, 2011
    3
    0
    I am a novice in programming and working on the design of a digital clock with calendar and temperature display. Though, I have soldered the project to working conditions, I am encountering some difficulties which I suspect to be from the source code.
    The problem is such that if I power the device, it seems to hang without showing the time, calendar and temperature. But after pressing the RESET button on several times it showed the data without running the clock and the current temperature is displayed only after I press the INCR button.
    Thus attached are the circuit diagram and source code, and I hope someone would help me out. Thanks in advance
     
  2. stahta01

    Member

    Jun 9, 2011
    133
    21
    FYI:
    I have looked at the attachments and this project is using an AT89S52 MCU and I think a DS12C88?7? RTC.

    I am not certain the RTC reset is hooked up correctly based on my reading of data-sheet. Note: I am also not certain it is hooked up wrong. Edit: after re-reading the RTC datasheet, I would say the RTC reset should work correctly as it is shown on diagram. But, I am far from an expert.

    But, I have little other help/info to offer.

    Tim S.
     
    Last edited: Jul 5, 2011
  3. stahta01

    Member

    Jun 9, 2011
    133
    21
    I see a possible problem. Correction, per the datasheet; if pin 1 of RTC is ground the Chip is in Intel Mode.

    So all the follows is wrong; because it was assuming Motorola mode (Pin 1 high).

    The MCU is an RD and WR chip; while the RTC is an R/W chip.
    Hooking these two together will likely require logic chips.
    I fail to see any logic chips. I see WR directly connect to R/W; this is likely not going to work. I suggest you confirm this will work correctly by reading the data-sheets and looking at example circuits.

    Tim S.
     
    Last edited: Jul 5, 2011
  4. stahta01

    Member

    Jun 9, 2011
    133
    21
    I suggest confirming the Chips used and posting the ASM code; I have never had 8051 ASM( Only used C); so, I have no idea if the source code is bad.

    But, everything I thought might have been wrong in the circuit looks to be correct.
    Note: I have not worked on any 8051 hardware for over two years and then I just helped a person on a class project using Silabs Chip.

    Tim S.
     
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