Questions and Problems by DS1307 RTC

[Saeedk9574]

Hi Everyone,
It has been a few days that I have been struggling with DS1307 RTC and I have some questions and problems. I should mention I had tested a library for ds1307 on its prepared module, then I decided to make the circuit separately with its components. These are the ds1307 module pic and its circuit diagram. In addition I attached ds1307 and its module datasheet here. However, there was not appropriate datasheet for its module.

1. Based on the datasheet ds1307 has 56B nvSRAM, so my first question is what is the usage of eeprom in this module? is it necessary to use eeprom on my board or not?

2. Second, I have a very big problem. After creating this circuit on PCB, it works correctly when the board is fixed o its place. But sometimes by a simple movement of board the timer gets stuck and sometimes it works well. My first guess was the crystal oscillator stops working by moving the board. But then I decided to touch crystal by my hand to test it and it was OK. I do not know where is the problem.

3. I should mention the only difference between the module and my circuit is the type of eeprom. Module has a 32K eeprom (24c32), but I used a 1k eeprom (24AA01). Can this difference affect the performance. I still do not know the usage of eeprom here.

 

[D.A.(Tony)Stewart]

I wonder if the internal NVRAM stores the interrupts from the AT scheduled command from NT in Windoze.

The AT command schedules commands and programs to run on a computer at
a specified time and date. The Schedule service must be running to use
the AT command.

AT [\\computername] [ [id] [/DELETE] | /DELETE [/YES]]
AT [\\computername] time [/INTERACTIVE]
    [ /EVERY:date[,...] | /NEXT:date[,...]] "command"

\\computername     Specifies a remote computer. Commands are scheduled on the
                   local computer if this parameter is omitted.
id                 Is an identification number assigned to a scheduled
                   command.
/delete            Cancels a scheduled command. If id is omitted, all the
                   scheduled commands on the computer are canceled.
/yes               Used with cancel all jobs command when no further
                   confirmation is desired.
time               Specifies the time when command is to run.
/interactive       Allows the job to interact with the desktop of the user
                   who is logged on at the time the job runs.
/every:date[,...]  Runs the command on each specified day(s) of the week or
                   month. If date is omitted, the current day of the month
                   is assumed.
/next:date[,...]   Runs the specified command on the next occurrence of the
                   day (for example, next Thursday).  If date is omitted, the
                   current day of the month is assumed.
"command"          Is the Windows NT command, or batch program to be run.