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RPi-WiringPi-2.36.6
River stage one • 1 direct dependent • 1 total dependent
8 ++
/ RPi::WiringPi

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;

    #
    # pin
    #

    my $pin = $pi->pin(5);
    $pin->mode(OUTPUT);
    $pin->write(ON);

    my $num = $pin->num;
    my $mode = $pin->mode;
    my $state = $pin->read;

    #
    # analog to digital converter
    #

    my $adc = $pi->adc;
   
    # read channel A0 on the ADC

    my $v = $adc->volts(0);
    my $p = $adc->percent(0);

    #
    # SPI
    #

    my $channel = 0; # SPI channel /dev/spidev0.0

    my $spi = $pi->spi($channel);

    my $buf = [0x01, 0x02];
    my $len = scalar @$buf;

    my @read_bytes = $spi->rw($buf, $len);

    #
    # digital potentiometer
    #

    my $cs = 18;     # GPIO pin connected to dpot CS pin
    my $channel = 0; # SPI channel /dev/spidev0.0

    my $dpot = $pi->dpot($cs, $channel);

    # set to 50% output

    $dpot->set(127);

    # shutdown (sleep) the potentiometer

    $dpot->shutdown;

    #
    # shift register
    #
    
    my ($base, $num_pins, $data, $clk, $latch)
      = (100, 8, 5, 6, 13);

    $pi->shift_register(
        $base, $num_pins, $data, $clk, $latch
    );

    # now we can access the new 8 pins of the
    # register commencing at new pin 100-107

    for (100..107){
        my $pin = $pi->pin($_);
        $pin->write(HIGH);
    }

    #
    # BMP180 barometric pressure sensor
    #
    
    my $base = 300; 

    my $bmp = $pi->bmp($base);

    my $farenheit = $bmp->temp;
    my $celcius   = $bmp->temp('c');
    my $pressure  = $bmp->pressure; # kPa

    #
    # LCD
    #

    my $lcd = $pi->lcd;

    $lcd->init(...);

    # first column, first row
    
    $lcd->position(0, 0); 
    $lcd->print("hi there!");

    # 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 (v2.36+).

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.

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 to die() is trapped, by default, we clean up, and then exit(). Set fatal_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:

    $pin_num

Mandatory: The pin number to attach to.

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().

spi($channel, $speed);

Creates a new RPi::SPI object which allows you to communicate on the Serial Peripheral Interface (SPI) bus with attached devices.

See the linked documentation for full documentation on usage, or the RPi::WiringPi::FAQ-Tutorial for usage examples.

dpot($cs, $channel)

Returns a RPi::DigiPot::MCP4XXXX object, which allows you to manage a digital potentiometer (only the MCP4XXXX versions are currently supported).

See the linked documentation for full documentation on usage, or the RPi::WiringPi::FAQ-Tutorial for usage examples.

shift_register($base, $num_pins, $data, $clk, $latch)

Allows you to access the output pins of up to four 74HC595 shift registers in series, for a total of eight new output pins per register. Numerous chains of four registers are permitted, each chain uses three GPIO pins.

Parameters:

    $base

Mandatory: Integer, represents the number at which you want to start referencing the new output pins attached to the register(s). For example, if you use 100 here, output pin 0 of the register will be 100, output 1 will be 101 etc.

    $num_pins

Mandatory: Integer, the number of output pins on the registers you want to use. Each register has eight outputs, so if you have a single register in use, the maximum number of additional pins would be eight.

    $data

Mandatory: Integer, the GPIO pin number attached to the DS pin (14) on the shift register.

    $clk

Mandatory: Integer, the GPIO pin number attached to the SHCP pin (11) on the shift register.

    $latch

Mandatory: Integer, the GPIO pin number attached to the STCP pin (12) on the shift register.

adc()

Returns a RPi::ADC::ADS object, which allows you to read the four analog input channels on an Adafruit ADS1xxx analog to digital converter.

Parameters:

The default (no parameters) is almost always enough, but please do review the documentation in the link above for further information, and have a look at the ADC tutorial section in this distribution.

bmp()

Returns a RPi::WiringPi::BMP180 object, which allows you to return the current temperature in farenheit or celcius, along with the ability to retrieve the barometric pressure in kPa.

INTERNAL PUBLIC METHODS

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.