NAME
RPi::WiringPi - Perl interface to Raspberry Pi's board, GPIO, LCDs and other various items
SYNOPSIS
use RPi::WiringPi;
use RPi::WiringPi::Constant qw(:all);
my $pi = RPi::WiringPi->new;
my $board_revision = $pi->rev;
# pin
my $pin = $pi->pin(5);
$pin->mode(OUTPUT);
$pin->write(ON);
my $num = $pin->num;
my $mode = $pin->mode;
my $state = $pin->read;
# LCD
my $lcd = $pi->lcd;
$lcd->init(...);
# first column, first row
$lcd->position(0, 0);
$lcd->print("Pi rev: $board_revision");
# first column, second row
$lcd->position(0, 1);
$lcd->print("pin $num... mode: $mode, state: $state");
$lcd->clear;
$lcd->display(OFF);
$pi->cleanup;
DESCRIPTION
This is the root module for the RPi::WiringPi
system. It interfaces to a Raspberry Pi board, its accessories and its GPIO pins via the wiringPi library through the Perl wrapper WiringPi::API module.
wiringPi must be installed prior to installing/using this module.
The scripts you write using this software must be run as the root
user (preferrably using sudo
, if configured properly... see RPi::WiringPi::FAQ).
By default, we set up using the GPIO
numbering scheme for pins. See new()
method for information on how to change this.
This module is essentially a 'manager' for the sub-modules (ie. components). You can use the component modules directly, but retrieving components through this module instead has many benefits. We maintain a registry of pins and other data. We also trap $SIG{__DIE__}
and $SIG{INT}
, so that in the event of a crash, we can reset the Pi back to default settings, so components are not left in an inconsistent state. Component moduls do none of these things.
There are a basic set of constants that can be imported. See RPi::WiringPi::Constant.
It's handy to have access to a pin mapping conversion chart. There's an excellent pin scheme map for reference at pinout.xyz. You can also run the pinmap
command that was installed by this module, or wiringPi
's gpio readall
command.
OPERATIONAL METHODS
See RPi::WiringPi::Util for utility/helper methods that are imported into an RPi::WiringPi
object.
new(%args)
Returns a new RPi::WiringPi
object. By default, we set the pin numbering scheme to GPIO
(Broadcom (BCM) GPIO scheme).
Parameters:
- setup => $value
-
Optional. This option specifies which pin mapping (numbering scheme) to use.
wpi: wiringPi's numbering phys: physical pin numbering gpio: GPIO numbering
You can also specify
none
for testing purposes. This will bypass running the setup routines.See wiringPi setup reference for the full details on the differences.
There's an excellent pin scheme map for reference at pinout.xyz. You can also run the
pinmap
application that was included in this distribution from the command line to get a printout of pin mappings.
- fatal_exit => $bool
-
Optional: We trap all
die()
calls and clean up for safety reasons. If a call todie()
is trapped, by default, we clean up, and thenexit()
. Setfatal_exit
to false (0
) to perform the cleanup, and then continue running your script. This is for unit testing purposes only.
pin($pin_num)
Returns a RPi::WiringPi::Pin object, mapped to a specified GPIO pin, which you can then perform operations on.
Parameters:
lcd()
Returns a RPi::WiringPi::LCD object, which allows you to fully manipulate LCD displays connected to your Raspberry Pi.
interrupt($pin, $edge, $callback)
Returns a RPi::WiringPi::Interrupt object, which allows you to act when certain events occur (eg: a button press). This functionality is better used through the RPi::WiringPi::Pin object you created with pin()
.
rev()
Returns the revision of the Pi board.
pwm_range($range)
Changes the range of Pulse Width Modulation (PWM). The default is 0
through 1023
.
Parameters:
$range
Mandatory: An integer specifying the high-end of the range. The range always starts at 0
. Eg: if $range
is 359
, if you incremented PWM by 1
every second, you'd rotate a step motor one complete rotation in exactly one minute.
RUNNING TESTS
Please see RUNNING TESTS in the FAQ.
AUTHOR
Steve Bertrand, <steveb@cpan.org>
COPYRIGHT AND LICENSE
Copyright (C) 2016 by Steve Bertrand
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.18.2 or, at your option, any later version of Perl 5 you may have available.