NAME

    Device::Chip::DS1307 - chip driver for a DS1307

DESCRIPTION

    This Device::Chip subclass provides specific communication to a Maxim
    Integrated DS1307 chip attached to a computer via an I²C adapter.

METHODS

    The following methods documented with a trailing call to ->get return
    Future instances.

 read_FIELD

       $v = $ds->read_I<FIELD>->get

    Reads a timekeeping field and returns a decimal integer. The following
    fields are recognised:

     seconds minutes hours wday mday month year

    The hours field is always returned in 24-hour mode, even if the chip is
    in 12-hour ("AM/PM") mode.

 write_FIELD

       $ds->write_I<FIELD>->get

    Writes a timekeeping field as a decimal integer. The following fields
    are recognised:

     seconds minutes hours wday mday month year

    The hours field is always written back in 24-hour mode.

 read_time

       @tm = $ds->read_time->get

    Returns a 7-element struct tm-compatible list of values by reading the
    timekeeping registers, suitable for passing to POSIX::mktime, etc...
    Note that the returned list does not contain the yday or is_dst fields.

    Because the DS1307 only stores a 2-digit year number, the year is
    presumed to be in the range 2000-2099.

    This method presumes POSIX-compatible semantics for the wday field
    stored on the chip; i.e. that 0 is Sunday.

    This method performs an atomic reading of all the timekeeping registers
    as a single I2C transaction, so is preferrable to invoking multiple
    calls to individual read methods.

 write_time

       $ds->write_time( @tm )->get

    Writes the timekeeping registers from a 7-element struct tm-compatible
    list of values. This method ignores the yday and is_dst fields, if
    present.

    Because the DS1307 only stores a 2-digit year number, the year must be
    in the range 2000-2099 (i.e. numerical values of 100 to 199).

    This method performs an atomic writing of all the timekeeping registers
    as a single I2C transaction, so is preferrable to invoking multiple
    calls to individual write methods.

AUTHOR

    Paul Evans <leonerd@leonerd.org.uk>

