++ed by:
STEVEB REISINGE TSIBLEY KEEDI

4 PAUSE users

Steve Bertrand

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 (ADS1115)
    #

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

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

    # analog to digital converter (MCP3008)

    my $adc = $pi->adc(model => 'MCP3008', channel => 0);

    print $adc->raw(0);
    print $adc->percent(0);

    #
    # I2C
    #

    my $device_addr = 0x7c;

    my $i2c_device = $pi->i2c($device_addr);

    my $register = 0x0A;

    $i2c_device->write_block([55, 29, 255], $register);

    my $byte = $i2c_device->read;

    my @bytes = $i2c_device->read_block;

    #
    # 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);

    #
    # Serial
    #

    my $dev  = "/dev/ttyAMA0";
    my $baud = 115200;

    my $ser = $pi->serial($dev, $baud);

    $ser->putc(5);

    my $char = $ser->getc;

    $ser->puts("hello, world!");

    my $num_bytes = 12;
    my $str  = $ser->gets($num_bytes);

    $ser->flush;

    my $bytes_available = $ser->avail;

    #
    # digital to analog converter (DAC)
    #

    my $dac_cs_pin = $pi->pin(29);
    my $spi_chan = 0;

    my $dac = $pi->dac(
        model   => 'MCP4922',
        channel => $spi_chan,
        cs      => $dac_cs_pin
    );

    my ($dacA, $dacB) = (0, 0);

    $dac->set($dacA, 4095); # 100% output
    $dac->set($dacB, 0);    # 0% output

    #
    # 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

    #
    # DHT11 temperature/humidity sensor
    #

    my $sensor_pin = 21;

    my $env = $pi->hygrometer($sensor_pin);

    my $humidity  = $env->humidity;
    my $temp      = $env->temp; # celcius
    my $farenheit = $env->temp('f');

    # GPS (requires gpsd to be installed and running)

    my $gps = $pi->gps;

    print $gps->tpv('lat')   . "\n";
    print $gps->tpv('lon')   . "\n";
    print $gps->tpv('speed') . "\n";
    print $gps->direction    . "\n";

    #
    # LCD
    #

    my $lcd = $pi->lcd(...);

    # 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;

    #
    # ultrasonic distance sensor
    #

    my $trig_pin = 23;
    my $echo_pin = 24;

    my $ruler = $pi->hcsr04($trig_pin, $echo_pin);

    my $inches = $sensor->inch;
    my $cm     = $sensor->cm;
    my $raw    = $sensor->raw;

    #
    # servo
    #

    my $pin_num = 18;

    my $servo = $pi->servo($pin_num);

    $servo->pwm(150); # centre position
    $servo->pwm(50);  # left position
    $servo->pwm(250); # right position

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, and various other custom device specific modules.

wiringPi must be installed prior to installing/using this module (v2.36+).

We always and only use the GPIO pin numbering scheme. These are the pin numbers that are printed on the Pi board itself.

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 modules 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. We exclusively use the GPIO (Broadcom (BCM) GPIO) pin numbering scheme. These pin numbers are printed on the Pi's board itself.

Parameters:

    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::Pin object, mapped to a specified GPIO pin, which you can then perform operations on. See that documentation for full usage details.

Parameters:

    $pin_num

Mandatory, Integer: The pin number to attach to.

lcd(...)

Returns a RPi::LCD object, which allows you to fully manipulate LCD displays connected to your Raspberry Pi.

Please see the linked documentation for information regarding the parameters required.

i2c($addr, [$device])

Creates a new RPi::I2C device object which allows you to communicate with the devices on an I2C bus.

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

serial($device, $baud)

Creates a new RPi::Serial object which allows basic read/write access to a serial bus.

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

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.

gps

Returns a GPSD::Parse object, allowing you to track your location.

The GPS distribution requires gpsd to be installed and running. All parameters for the GPS can be sent in here and we'll pass them along. Please see the link above for the full documentation on that module.

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()

There are two different ADCs that you can select from. The default is the ADS1x15 series:

ADS1115

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.

MCP3008

You can also use an RPi::ADC::MCP3008 ADC.

Parameters:

    model => 'MCP3008'

Mandatory, String. The exact quoted string above.

    channel => $channel

Mandatory, Integer. 0 or 1 for the Pi's onboard hardware CS/SS CE0 and CE1 pins, or any GPIO number above 1 in order to use an arbitrary GPIO pin for the CS pin, and we'll do the bit-banging of the SPI bus automatically.

dac(model => 'MCP4922')

Returns a RPi::DAC::MCP4922 object (supports all 49x2 series DACs). These chips provide analog output signals from the Pi's digital output. Please see the documentation of that module for further information on both the configuration and use of the DAC object.

Note that if the model parameter is not sent in, we default to MCP4922.

bmp()

Returns a RPi::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.

hygrometer($pin)

Returns a RPi::DHT11 temperature/humidity sensor object, allows you to fetch the temperature (celcius or farenheit) as well as the current humidity level.

hcsr04($trig, $echo)

Returns a RPi::HCSR04 ultrasonic distance measurement sensor object, allowing you to retrieve the distance from the sensor in inches, centimetres or raw data.

Parameters:

    $trig

The trigger pin number, in GPIO numbering scheme.

    $echo

The echo pin number, in GPIO numbering scheme.

servo($pin_num)

This method configures PWM clock and divisor to operate a typical 50Hz servo, and returns a special RPi::Pin object. These servos have a left pulse of 50, a centre pulse of 150 and a right pulse of 250. On exit of the program (or a crash), we automatically clean everything up properly.

Parameters:

    $pin_num

Mandatory, Integer: The pin number (technically, this *must* be 18 on the Raspberry Pi 3, as that's the only hardware PWM pin.

Example:

    my $servo = $pi->servo(18);

    $servo->pwm(50);  # all the way left
    $servo->pwm(250); # all the way right

INTERNAL PUBLIC METHODS

RUNNING TESTS

Please see RUNNING TESTS in the FAQ.

AUTHOR

Steve Bertrand, <steveb@cpan.org>

COPYRIGHT AND LICENSE

Copyright (C) 2017 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.