Perl - IO-4 Bricklet

This is the description of the Perl API bindings for the IO-4 Bricklet. General information and technical specifications for the IO-4 Bricklet are summarized in its hardware description.

An installation guide for the Perl API bindings is part of their general description.

Examples

The example code below is Public Domain (CC0 1.0).

Input

Download (example_input.pl)

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#!/usr/bin/perl

use strict;
use Tinkerforge::IPConnection;
use Tinkerforge::BrickletIO4;

use constant HOST => 'localhost';
use constant PORT => 4223;
use constant UID => 'XYZ'; # Change XYZ to the UID of your IO-4 Bricklet

my $ipcon = Tinkerforge::IPConnection->new(); # Create IP connection
my $io = Tinkerforge::BrickletIO4->new(&UID, $ipcon); # Create device object

$ipcon->connect(&HOST, &PORT); # Connect to brickd
# Don't use device before ipcon is connected

# Get current value as bitmask
my $value_mask = $io->get_value();
print "Value Mask: " . sprintf('%04b', $value_mask) . "\n";

print "Press key to exit\n";
<STDIN>;
$ipcon->disconnect();

Output

Download (example_output.pl)

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#!/usr/bin/perl

use strict;
use Tinkerforge::IPConnection;
use Tinkerforge::BrickletIO4;

use constant HOST => 'localhost';
use constant PORT => 4223;
use constant UID => 'XYZ'; # Change XYZ to the UID of your IO-4 Bricklet

my $ipcon = Tinkerforge::IPConnection->new(); # Create IP connection
my $io = Tinkerforge::BrickletIO4->new(&UID, $ipcon); # Create device object

$ipcon->connect(&HOST, &PORT); # Connect to brickd
# Don't use device before ipcon is connected

# Set pin 1 to output low
$io->set_configuration(1 << 1, 'o', 0);

# Set pin 2 and 3 to output high
$io->set_configuration((1 << 2) | (1 << 3), 'o', 1);

print "Press key to exit\n";
<STDIN>;
$ipcon->disconnect();

Interrupt

Download (example_interrupt.pl)

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#!/usr/bin/perl

use strict;
use Tinkerforge::IPConnection;
use Tinkerforge::BrickletIO4;

use constant HOST => 'localhost';
use constant PORT => 4223;
use constant UID => 'XYZ'; # Change XYZ to the UID of your IO-4 Bricklet

# Callback subroutine for interrupt callback
sub cb_interrupt
{
    my ($interrupt_mask, $value_mask) = @_;

    print "Interrupt Mask: " . sprintf('%04b', $interrupt_mask) . "\n";
    print "Value Mask: " . sprintf('%04b', $value_mask) . "\n";
    print "\n";
}

my $ipcon = Tinkerforge::IPConnection->new(); # Create IP connection
my $io = Tinkerforge::BrickletIO4->new(&UID, $ipcon); # Create device object

$ipcon->connect(&HOST, &PORT); # Connect to brickd
# Don't use device before ipcon is connected

# Register interrupt callback to subroutine cb_interrupt
$io->register_callback($io->CALLBACK_INTERRUPT, 'cb_interrupt');

# Enable interrupt on pin 0
$io->set_interrupt(1 << 0);

print "Press key to exit\n";
<STDIN>;
$ipcon->disconnect();

API

Generally, every subroutine of the Perl bindings can report an error as Tinkerforge::Error object via croak(). The object has a get_code() and a get_message() subroutine. There are different error code:

  • Error->ALREADY_CONNECTED = 11
  • Error->NOT_CONNECTED = 12
  • Error->CONNECT_FAILED = 13
  • Error->INVALID_FUNCTION_ID = 21
  • Error->TIMEOUT = 31
  • Error->INVALID_PARAMETER = 41
  • Error->FUNCTION_NOT_SUPPORTED = 42
  • Error->UNKNOWN_ERROR = 43
  • Error->STREAM_OUT_OF_SYNC = 51
  • Error->INVALID_UID = 61
  • Error->NON_ASCII_CHAR_IN_SECRET = 71

All methods listed below are thread-safe.

Basic Functions

BrickletIO4->new($uid, $ipcon)
Parameters:
  • $uid – Type: string
  • $ipcon – Type: IPConnection
Returns:
  • $io4 – Type: BrickletIO4

Creates an object with the unique device ID $uid:

$io4 = BrickletIO4->new("YOUR_DEVICE_UID", $ipcon);

This object can then be used after the IP Connection is connected (see examples above).

BrickletIO4->set_value($value_mask)
Parameters:
  • $value_mask – Type: int, Range: [0 to 255]
Returns:
  • undef

Sets the output value (high or low) with a bitmask (4bit). A 1 in the bitmask means high and a 0 in the bitmask means low.

For example: The value 3 or 0b0011 will turn the pins 0-1 high and the pins 2-3 low.

All running monoflop timers will be aborted if this function is called.

Note

This function does nothing for pins that are configured as input. Pull-up resistors can be switched on with set_configuration().

BrickletIO4->get_value()
Returns:
  • $value_mask – Type: int, Range: [0 to 255]

Returns a bitmask of the values that are currently measured. This function works if the pin is configured to input as well as if it is configured to output.

BrickletIO4->set_configuration($selection_mask, $direction, $value)
Parameters:
  • $selection_mask – Type: int, Range: [0 to 255]
  • $direction – Type: char, Range: See constants
  • $value – Type: bool
Returns:
  • undef

Configures the value and direction of the specified pins. Possible directions are 'i' and 'o' for input and output.

If the direction is configured as output, the value is either high or low (set as true or false).

If the direction is configured as input, the value is either pull-up or default (set as true or false).

For example:

  • (15, 'i', true) or (0b1111, 'i', true) will set all pins of as input pull-up.
  • (8, 'i', false) or (0b1000, 'i', false) will set pin 3 of as input default (floating if nothing is connected).
  • (3, 'o', false) or (0b0011, 'o', false) will set pins 0 and 1 as output low.
  • (4, 'o', true) or (0b0100, 'o', true) will set pin 2 of as output high.

Running monoflop timers for the specified pins will be aborted if this function is called.

The default configuration is input with pull-up.

The following constants are available for this function:

For $direction:

  • BrickletIO4->DIRECTION_IN = 'i'
  • BrickletIO4->DIRECTION_OUT = 'o'
BrickletIO4->get_configuration()
Return Array:
  • 0: $direction_mask – Type: int, Range: [0 to 255]
  • 1: $value_mask – Type: int, Range: [0 to 255]

Returns a value bitmask and a direction bitmask. A 1 in the direction bitmask means input and a 0 in the bitmask means output.

For example: A return value of (3, 5) or (0b0011, 0b0101) for direction and value means that:

  • pin 0 is configured as input pull-up,
  • pin 1 is configured as input default,
  • pin 2 is configured as output high and
  • pin 3 is are configured as output low.
BrickletIO4->get_edge_count($pin, $reset_counter)
Parameters:
  • $pin – Type: int, Range: [0 to 255]
  • $reset_counter – Type: bool
Returns:
  • $count – Type: int, Range: [0 to 232 - 1]

Returns the current value of the edge counter for the selected pin. You can configure the edges that are counted with set_edge_count_config().

If you set the reset counter to true, the count is set back to 0 directly after it is read.

New in version 2.0.1 (Plugin).

Advanced Functions

BrickletIO4->set_monoflop($selection_mask, $value_mask, $time)
Parameters:
  • $selection_mask – Type: int, Range: [0 to 255]
  • $value_mask – Type: int, Range: [0 to 255]
  • $time – Type: int, Range: [0 to 232 - 1]
Returns:
  • undef

Configures a monoflop of the pins specified by the first parameter as 4 bit long bitmask. The specified pins must be configured for output. Non-output pins will be ignored.

The second parameter is a bitmask with the desired value of the specified output pins. A 1 in the bitmask means high and a 0 in the bitmask means low.

The third parameter indicates the time (in ms) that the pins should hold the value.

If this function is called with the parameters (9, 1, 1500) or (0b1001, 0b0001, 1500): Pin 0 will get high and pin 3 will get low. In 1.5s pin 0 will get low and pin 3 will get high again.

A monoflop can be used as a fail-safe mechanism. For example: Lets assume you have a RS485 bus and an IO-4 Bricklet connected to one of the slave stacks. You can now call this function every second, with a time parameter of two seconds and pin 0 set to high. Pin 0 will be high all the time. If now the RS485 connection is lost, then pin 0 will get low in at most two seconds.

BrickletIO4->get_monoflop($pin)
Parameters:
  • $pin – Type: int, Range: [0 to 255]
Return Array:
  • 0: $value – Type: int, Range: [0 to 255]
  • 1: $time – Type: int, Range: [0 to 232 - 1]
  • 2: $time_remaining – Type: int, Range: [0 to 232 - 1]

Returns (for the given pin) the current value and the time as set by set_monoflop() as well as the remaining time until the value flips.

If the timer is not running currently, the remaining time will be returned as 0.

BrickletIO4->set_selected_values($selection_mask, $value_mask)
Parameters:
  • $selection_mask – Type: int, Range: [0 to 255]
  • $value_mask – Type: int, Range: [0 to 255]
Returns:
  • undef

Sets the output value (high or low) with a bitmask, according to the selection mask. The bitmask is 4 bit long, true refers to high and false refers to low.

For example: The parameters (9, 4) or (0b0110, 0b0100) will turn pin 1 low and pin 2 high, pin 0 and 3 will remain untouched.

Running monoflop timers for the selected pins will be aborted if this function is called.

Note

This function does nothing for pins that are configured as input. Pull-up resistors can be switched on with set_configuration().

BrickletIO4->set_edge_count_config($selection_mask, $edge_type, $debounce)
Parameters:
  • $selection_mask – Type: int, Range: [0 to 255]
  • $edge_type – Type: int, Range: See constants
  • $debounce – Type: int, Range: [0 to 255]
Returns:
  • undef

Configures the edge counter for the selected pins.

The edge type parameter configures if rising edges, falling edges or both are counted if the pin is configured for input. Possible edge types are:

  • 0 = rising (default)
  • 1 = falling
  • 2 = both

The debounce time is given in ms.

Configuring an edge counter resets its value to 0.

If you don't know what any of this means, just leave it at default. The default configuration is very likely OK for you.

Default values: 0 (edge type) and 100ms (debounce time)

The following constants are available for this function:

For $edge_type:

  • BrickletIO4->EDGE_TYPE_RISING = 0
  • BrickletIO4->EDGE_TYPE_FALLING = 1
  • BrickletIO4->EDGE_TYPE_BOTH = 2

New in version 2.0.1 (Plugin).

BrickletIO4->get_edge_count_config($pin)
Parameters:
  • $pin – Type: int, Range: [0 to 255]
Return Array:
  • 0: $edge_type – Type: int, Range: See constants
  • 1: $debounce – Type: int, Range: [0 to 255]

Returns the edge type and debounce time for the selected pin as set by set_edge_count_config().

The following constants are available for this function:

For $edge_type:

  • BrickletIO4->EDGE_TYPE_RISING = 0
  • BrickletIO4->EDGE_TYPE_FALLING = 1
  • BrickletIO4->EDGE_TYPE_BOTH = 2

New in version 2.0.1 (Plugin).

BrickletIO4->get_api_version()
Returns:
  • @api_version – Type: [int, ...], Length: 3, Range: [0 to 255]

Returns the version of the API definition (major, minor, revision) implemented by this API bindings. This is neither the release version of this API bindings nor does it tell you anything about the represented Brick or Bricklet.

BrickletIO4->get_response_expected($function_id)
Parameters:
  • $function_id – Type: int, Range: See constants
Returns:
  • $response_expected – Type: bool

Returns the response expected flag for the function specified by the function ID parameter. It is true if the function is expected to send a response, false otherwise.

For getter functions this is enabled by default and cannot be disabled, because those functions will always send a response. For callback configuration functions it is enabled by default too, but can be disabled by set_response_expected(). For setter functions it is disabled by default and can be enabled.

Enabling the response expected flag for a setter function allows to detect timeouts and other error conditions calls of this setter as well. The device will then send a response for this purpose. If this flag is disabled for a setter function then no response is send and errors are silently ignored, because they cannot be detected.

The following constants are available for this function:

For $function_id:

  • BrickletIO4->FUNCTION_SET_VALUE = 1
  • BrickletIO4->FUNCTION_SET_CONFIGURATION = 3
  • BrickletIO4->FUNCTION_SET_DEBOUNCE_PERIOD = 5
  • BrickletIO4->FUNCTION_SET_INTERRUPT = 7
  • BrickletIO4->FUNCTION_SET_MONOFLOP = 10
  • BrickletIO4->FUNCTION_SET_SELECTED_VALUES = 13
  • BrickletIO4->FUNCTION_SET_EDGE_COUNT_CONFIG = 15
BrickletIO4->set_response_expected($function_id, $response_expected)
Parameters:
  • $function_id – Type: int, Range: See constants
  • $response_expected – Type: bool
Returns:
  • undef

Changes the response expected flag of the function specified by the function ID parameter. This flag can only be changed for setter (default value: false) and callback configuration functions (default value: true). For getter functions it is always enabled.

Enabling the response expected flag for a setter function allows to detect timeouts and other error conditions calls of this setter as well. The device will then send a response for this purpose. If this flag is disabled for a setter function then no response is send and errors are silently ignored, because they cannot be detected.

The following constants are available for this function:

For $function_id:

  • BrickletIO4->FUNCTION_SET_VALUE = 1
  • BrickletIO4->FUNCTION_SET_CONFIGURATION = 3
  • BrickletIO4->FUNCTION_SET_DEBOUNCE_PERIOD = 5
  • BrickletIO4->FUNCTION_SET_INTERRUPT = 7
  • BrickletIO4->FUNCTION_SET_MONOFLOP = 10
  • BrickletIO4->FUNCTION_SET_SELECTED_VALUES = 13
  • BrickletIO4->FUNCTION_SET_EDGE_COUNT_CONFIG = 15
BrickletIO4->set_response_expected_all($response_expected)
Parameters:
  • $response_expected – Type: bool
Returns:
  • undef

Changes the response expected flag for all setter and callback configuration functions of this device at once.

BrickletIO4->get_identity()
Return Array:
  • 0: $uid – Type: string, Length: up to 8
  • 1: $connected_uid – Type: string, Length: up to 8
  • 2: $position – Type: char
  • 3: @hardware_version – Type: [int, ...], Length: 3, Range: [0 to 255]
  • 4: @firmware_version – Type: [int, ...], Length: 3, Range: [0 to 255]
  • 5: $device_identifier – Type: int, Range: [0 to 216 - 1]

Returns the UID, the UID where the Bricklet is connected to, the position, the hardware and firmware version as well as the device identifier.

The position can be 'a', 'b', 'c' or 'd'.

The device identifier numbers can be found here. There is also a constant for the device identifier of this Bricklet.

Callback Configuration Functions

BrickletIO4->register_callback($callback_id, $function)
Parameters:
  • $callback_id – Type: int
  • $function – Type: string
Returns:
  • undef

Registers the given $function name with the given $callback_id.

The available callback IDs with corresponding function signatures are listed below.

BrickletIO4->set_debounce_period($debounce)
Parameters:
  • $debounce – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 100
Returns:
  • undef

Sets the debounce period of the CALLBACK_INTERRUPT callback.

For example: If you set this value to 100, you will get the interrupt maximal every 100ms. This is necessary if something that bounces is connected to the IO-4 Bricklet, such as a button.

BrickletIO4->get_debounce_period()
Returns:
  • $debounce – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 100

Returns the debounce period as set by set_debounce_period().

BrickletIO4->set_interrupt($interrupt_mask)
Parameters:
  • $interrupt_mask – Type: int, Range: [0 to 255]
Returns:
  • undef

Sets the pins on which an interrupt is activated with a bitmask. Interrupts are triggered on changes of the voltage level of the pin, i.e. changes from high to low and low to high.

For example: An interrupt bitmask of 10 or 0b1010 will enable the interrupt for pins 1 and 3.

The interrupt is delivered with the CALLBACK_INTERRUPT callback.

BrickletIO4->get_interrupt()
Returns:
  • $interrupt_mask – Type: int, Range: [0 to 255]

Returns the interrupt bitmask as set by set_interrupt().

Callbacks

Callbacks can be registered to receive time critical or recurring data from the device. The registration is done with the register_callback() function of the device object. The first parameter is the callback ID and the second parameter the callback function name:

sub my_callback
{
    print "@_[0]";
}

$io4->register_callback(BrickletIO4->CALLBACK_EXAMPLE, 'my_callback')

The callback function will be called from an internal thread of the IP Connection. In contrast to many other programming languages, variables are not automatically shared between threads in Perl. If you want to share a global variable between a callback function and the rest for your program it has to be marked as :shared. See the documentation of the threads::shared Perl module for more details.

The available constants with inherent number and type of parameters are described below.

Note

Using callbacks for recurring events is always preferred compared to using getters. It will use less USB bandwidth and the latency will be a lot better, since there is no round trip time.

BrickletIO4->CALLBACK_INTERRUPT
Callback Parameters:
  • $interrupt_mask – Type: int, Range: [0 to 255]
  • $value_mask – Type: int, Range: [0 to 255]

This callback is triggered whenever a change of the voltage level is detected on pins where the interrupt was activated with set_interrupt().

The values are a bitmask that specifies which interrupts occurred and the current value bitmask.

For example:

  • (1, 1) or (0b0001, 0b0001) means that an interrupt on pin 0 occurred and currently pin 0 is high and pins 1-3 are low.
  • (9, 14) or (0b1001, 0b1110) means that interrupts on pins 0 and 3 occurred and currently pin 0 is low and pins 1-3 are high.
BrickletIO4->CALLBACK_MONOFLOP_DONE
Callback Parameters:
  • $selection_mask – Type: int, Range: [0 to 255]
  • $value_mask – Type: int, Range: [0 to 255]

This callback is triggered whenever a monoflop timer reaches 0. The parameters contain the involved pins and the current value of the pins (the value after the monoflop).

Constants

BrickletIO4->DEVICE_IDENTIFIER

This constant is used to identify a IO-4 Bricklet.

The get_identity() function and the IPConnection->CALLBACK_ENUMERATE callback of the IP Connection have a device_identifier parameter to specify the Brick's or Bricklet's type.

BrickletIO4->DEVICE_DISPLAY_NAME

This constant represents the human readable name of a IO-4 Bricklet.