NAME

Device::Chip::PCF8563 - chip driver for a PCF8563

DESCRIPTION

This Device::Chip subclass provides specific communication to a NXP PCF8563 chip attached to a computer via an I²C adapter.

METHODS

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

read_time

   @tm = $pcf->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 PCF8563 only stores a 2-digit year number plus a single century bit, the year is presumed to be in the range 2000-2199.

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

   $pcf->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 PCF8563 only stores a 2-digit year number and a century bit, the year must be in the range 2000-2199 (i.e. numerical values of 100 to 299).

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>