Device::USB::PCSensor::HidTEMPer::NTC::Internal - The HidTEMPerNTC internal sensor

Device-USB-PCSensor-HidTEMPer documentation

Contained in the Device-USB-PCSensor-HidTEMPer distribution.

Index

VERSION
SYNOPSIS
DESCRIPTION
INHERIT METHODS FROM
DEPENDENCIES
BUGS
FOR MORE INFORMATION
AUTHOR
ACKNOWLEDGEMENTS
COPYRIGHT & LICENSE

Code Index:

package Device::USB::PCSensor::HidTEMPer::NTC::Internal
- celsius
EOF

Device::USB::PCSensor::HidTEMPer::NTC::Internal - The HidTEMPerNTC internal sensor

VERSION

Version 0.03

SYNOPSIS

None

DESCRIPTION

This is the implementation of the HidTEMPerNTC internal sensor.

CONSTANTS

* MAX_TEMPERATURE: The highest temperature(120 degrees celsius) this sensor can detect.
* MIN_TEMPERATURE: The lowest temperature(-40 degrees celsius) this sensor can detect.

METHODS

* celsius(): Returns the current temperature from the device in celsius degrees.

INHERIT METHODS FROM

Device::USB::PCSensor::HidTEMPer::Sensor

DEPENDENCIES

This module internally includes and takes use of the following packages:

  use Device::USB::PCSensor::HidTEMPer::Sensor;

This module uses the strict and warning pragmas.

BUGS

Please report any bugs or missing features using the CPAN RT tool.

FOR MORE INFORMATION

None

AUTHOR

Magnus Sulland < msulland@cpan.org >

ACKNOWLEDGEMENTS

Thanks to Jean F. Delpech for the temperature fix that solves the problem with temperatures bellow 0 Celsius.

This code is inspired by Relavak's source code and the comments found at: http://relavak.wordpress.com/2009/10/17/

COPYRIGHT & LICENSE

Copyright (c) 2010-2011 Magnus Sulland

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

Device-USB-PCSensor-HidTEMPer documentation

Contained in the Device-USB-PCSensor-HidTEMPer distribution.

package Device::USB::PCSensor::HidTEMPer::NTC::Internal;

use strict;
use warnings;

use Device::USB::PCSensor::HidTEMPer::Sensor;
our @ISA = 'Device::USB::PCSensor::HidTEMPer::Sensor';

our $VERSION = 0.03;

use constant MAX_TEMPERATURE    => 120;

use constant MIN_TEMPERATURE    => -40;

sub celsius
{
    my $self    = shift;
    my @data    = ();
    my $reading = 0;
    
    # Command 0x54 will return the following 8 byte result, repeated 4 times.
    # Position 0: Signed int returning the main temperature reading
    # Position 1: Unsigned int divided by 256 to give presision.
    # Position 2: unknown
    # Position 3: unused
    # Position 4: unused
    # Position 5: unused
    # Position 6: unused
    # Position 7: unused
    
    # First reading
    @data       = $self->{unit}->_read( 0x54 );
    $reading    = ($data[0] < 128) ? $data[0] + ( $data[1] / 256 ) : ($data[0] - 255) - ( $data[1] / 256 );    

    # Secound reading
    @data       = $self->{unit}->_read( 0x54 );
    $reading    += ($data[0] < 128) ? $data[0] + ( $data[1] / 256 ) : ($data[0] - 255) - ( $data[1] / 256 );   

    # Return the average, this adds precision
    return $reading / 2;
}

1;