1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
|
#########################################################################################
# Package HiPi::Interface::PCF8574
# Description : Control NXP PCF8574 8-channel port extender
# Copyright : Copyright (c) 2013-2017 Mark Dootson
# License : This is free software; you can redistribute it and/or modify it under
# the same terms as the Perl 5 programming language system itself.
#########################################################################################
package HiPi::Interface::PCF8574;
#########################################################################################
use strict;
use warnings;
use parent qw( HiPi::Interface );
use HiPi qw( :i2c :rpi );
use Carp;
__PACKAGE__->create_ro_accessors( qw(
backend
) );
our $VERSION ='0.81';
sub new {
my ($class, %userparams) = @_;
my $pi = HiPi::RaspberryPi->new();
my %params = (
devicename => ( $pi->board_type == RPI_BOARD_TYPE_1 ) ? '/dev/i2c-0' : '/dev/i2c-1',
address => 0x3f,
device => undef,
backend => 'i2c',
);
# get user params
foreach my $key( keys (%userparams) ) {
$params{$key} = $userparams{$key};
}
unless( defined($params{device}) ) {
if ( $params{backend} eq 'bcm2835' ) {
require HiPi::BCM2835::I2C;
$params{device} = HiPi::BCM2835::I2C->new(
address => $params{address},
peripheral => ( $params{devicename} eq '/dev/i2c-0' ) ? HiPi::BCM2835::I2C::BB_I2C_PERI_0() : HiPi::BCM2835::I2C::BB_I2C_PERI_1(),
);
} else {
require HiPi::Device::I2C;
$params{device} = HiPi::Device::I2C->new(
devicename => $params{devicename},
address => $params{address},
busmode => $params{backend},
);
}
}
my $self = $class->SUPER::new(%params);
return $self;
}
sub read_byte {
my ( $self ) = @_;
my @bytes = $self->device->bus_read(undef, 1);
return $bytes[0];
}
sub write_byte {
my( $self, $byte) = @_;
$self->device->bus_write($byte & 0xFF);
}
sub read_bits {
my ( $self ) = @_;
my $byte = $self->read_byte;
my @bits;
for ( my $i = 0; $i < 8; $i++ ) {
push @bits, ( $byte >> $i ) & 1;
}
return @bits;
}
sub write_bits {
my( $self, @bits) = @_;
my $bitcount = @bits;
unless( $bitcount == 8 ) {
warn qq(Only $bitcount bits provided in write_bits. Needs 8);
return;
}
my $byte = 0;
for ( my $i = 0; $i < 8; $i++ ) {
$byte += ($bits[$i] & 1 ) << $i;
}
$self->write_byte( $byte );
}
sub set_bit {
my( $self, $bit, $value) = @_;
if($bit < 0 || $bit > 7) {
warn qq(Bit argument must be between 0 and 7 in set_bit. You passed $bit);
return;
}
if($value < 0 || $value > 1) {
warn qq(Value argument muist be 1 or 0 in set_bit. You passed $value);
return;
}
my @bits = $self->read_bits;
$bits[$bit] = $value;
$self->write_bits(@bits);
}
sub get_bit {
my( $self, $bit ) = @_;
if($bit < 0 || $bit > 7) {
warn qq(Bit argument must be between 0 and 7 in get_bit. You passed $bit);
return;
}
my @bits = $self->read_bits;
return $bits[$bit];
}
sub set_port { set_bit( @_ ); }
sub get_port { get_bit( @_ ); }
1;
__END__
|
