File Coverage

blib/lib/PINE64/MCP9808.pm

Criterion	Covered	Total	%
statement	3	28	10.7
branch	0	10	0.0
condition			n/a
subroutine	1	3	33.3
pod	2	2	100.0
total	6	43	13.9

#!/usr/bin/perl
use strict;

package PINE64::MCP9808;

our $VERSION = '0.905';

#global vars
my ($i2cbus, $addr) = ('','');

sub new{
	my $class = shift;
	my $self = bless {}, $class;

	$i2cbus = $_[0];
	$addr = $_[1];

	if($i2cbus eq ''){
		$i2cbus = 0;
	}#end if

	if($addr eq ''){
		$addr = '0x18';
	}#end if

	return $self;
}#end new

sub read_temperature{

	#reads ambient temperature reguster 0x05

	my $hrdg = `i2cget -y $i2cbus $addr 0x05 w`;
	my ($ubyte, $lbyte) = (0,0);

	#split into uppper and lower bytes
	$hrdg =~ /(..)(..)(..)/;
	$ubyte = $3;
	$lbyte = $2;

	#convert hex to decimal
	$ubyte = hex $ubyte;
	$lbyte = hex $lbyte;

	#convert reading to decimal temp
	#strip 15-13b
	if($ubyte > 127){$ubyte-=128;}
	if($ubyte > 63){$ubyte-=64;}
	if($ubyte > 31){$ubyte-=32;}

	my $celsius = ($ubyte * 16) + ($lbyte * 0.0625);
	my $fahrenheit = ($celsius * 1.8) + 32;

	return($celsius, $fahrenheit);
}#end read_temperature

1;
__END__