NAME

   Device::Chip::PCF8574 - chip driver for a PCF8574

DESCRIPTION

   This Device::Chip subclass provides specific communication to a NXP or
   Texas Instruments PCF8574 attached to a computer via an I�C adapter.

   The reader is presumed to be familiar with the general operation of
   this chip; the documentation here will not attempt to explain or define
   chip-specific concepts or features, only the use of this module to
   access them.

MOUNT PARAMETERS

addr

   The I�C address of the device. Can be specified in decimal, octal or
   hex with leading 0 or 0x prefixes.

METHODS

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

write

      $pcf->write( $val )->get

   Sets the value of the GPIO pins, as an 8-bit integer.

   Pins set low will sink current suitable for signalling or driving an
   LED. Pins set high will source current via a weak current-source to act
   as a pull-up for an active-low input signal, such as a button.

read

      $val = $pcf->read->get

   Reads the current logic levels on the GPIO pins, returned as an 8-bit
   integer. Pins of interest as inputs should have previously been set to
   high level using the "write" method.

as_adapter

      $adapter = $pcf->as_adapter

   Returns a new object implementing the Device::Chip::Adapter interface
   which allows access to the GPIO pins of the chip as if it was a GPIO
   protocol adapter. The returned instance supports the following methods:

      $protocol = $adapter->make_protocol( 'GPIO' )

      $protocol->list_gpios
      $protocol->write_gpios
      $protocol->read_gpios
      $protocol->tris_gpios

AUTHOR

   Paul Evans <[email protected]>

You are viewing proxied material from ftp.icm.edu.pl. The copyright of proxied material belongs to its original authors. Any comments or complaints in relation to proxied material should be directed to the original authors of the content concerned. Please see the disclaimer for more details.