Perl - IO-4 Bricklet 2.0

This is the description of the Perl API bindings for the IO-4 Bricklet 2.0. General information and technical specifications for the IO-4 Bricklet 2.0 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).

Output

Download (example_output.pl)

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#!/usr/bin/perl

use strict;
use Tinkerforge::IPConnection;
use Tinkerforge::BrickletIO4V2;

use constant HOST => 'localhost';
use constant PORT => 4223;
use constant UID => 'XYZ'; # Change XYZ to the UID of your IO-4 Bricklet 2.0

my $ipcon = Tinkerforge::IPConnection->new(); # Create IP connection
my $io = Tinkerforge::BrickletIO4V2->new(&UID, $ipcon); # Create device object

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

# Configure channel 3 as output low
$io->set_configuration(3, 'o', 0);

# Set channel 3 alternating high/low 10 times with 100 ms delay
for (my $i = 0; $i < 10; $i++)
{
    select(undef, undef, undef, 0.1);
    $io->set_selected_value(3, 1);
    select(undef, undef, undef, 0.1);
    $io->set_selected_value(3, 0);
}

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::BrickletIO4V2;

use constant HOST => 'localhost';
use constant PORT => 4223;
use constant UID => 'XYZ'; # Change XYZ to the UID of your IO-4 Bricklet 2.0

# Callback subroutine for input value callback
sub cb_input_value
{
    my ($channel, $changed, $value) = @_;

    print "Channel: $channel\n";
    print "Changed: $changed\n";
    print "Value: $value\n";
    print "\n";
}

my $ipcon = Tinkerforge::IPConnection->new(); # Create IP connection
my $io = Tinkerforge::BrickletIO4V2->new(&UID, $ipcon); # Create device object

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

# Register input value callback to subroutine cb_input_value
$io->register_callback($io->CALLBACK_INPUT_VALUE, 'cb_input_value');

# Set period for input value (channel 1) callback to 0.5s (500ms)
$io->set_input_value_callback_configuration(1, 500, 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

All methods listed below are thread-safe.

Basic Functions

BrickletIO4V2->new($uid, $ipcon)
Parameters:
  • $uid -- string
  • $ipcon -- IPConnection
Return type:

BrickletIO4V2

Creates an object with the unique device ID $uid:

$io4_v2 = BrickletIO4V2->new("YOUR_DEVICE_UID", $ipcon);

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

BrickletIO4V2->set_value(@value)
Parameters:@value -- [bool, bool, bool, bool]
Return type:undef

Sets the output value of all four channels. A value of true or false outputs logic 1 or logic 0 respectively on the corresponding channel.

Use set_selected_value() to change only one output channel state.

For example: (True, True, False, False) will turn the channels 0-1 high and the channels 2-3 low.

Note

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

BrickletIO4V2->get_value()
Return type:[bool, bool, bool, bool]

Returns the logic levels that are currently measured on the channels. This function works if the channel is configured as input as well as if it is configured as output.

BrickletIO4V2->set_selected_value($channel, $value)
Parameters:
  • $channel -- int
  • $value -- bool
Return type:

undef

Sets the output value of a specific channel without affecting the other channels.

Note

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

BrickletIO4V2->set_configuration($channel, $direction, $value)
Parameters:
  • $channel -- int
  • $direction -- char
  • $value -- bool
Return type:

undef

Configures the value and direction of a specific channel. 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:

  • (0, 'i', true) will set channel 0 as input pull-up.
  • (1, 'i', false) will set channel 1 as input default (floating if nothing is connected).
  • (2, 'o', true) will set channel 2 as output high.
  • (3, 'o', false) will set channel 3 as output low.

The default configuration is input with pull-up.

The following constants are available for this function:

  • BrickletIO4V2->DIRECTION_IN = 'i'
  • BrickletIO4V2->DIRECTION_OUT = 'o'

Advanced Functions

BrickletIO4V2->set_monoflop($channel, $value, $time)
Parameters:
  • $channel -- int
  • $value -- bool
  • $time -- int
Return type:

undef

The first parameter is the desired state of the channel (true means output high and false means output low). The second parameter indicates the time (in ms) that the channel should hold the state.

If this function is called with the parameters (true, 1500): The channel will turn on and in 1.5s it will turn off again.

A monoflop can be used as a failsafe mechanism. For example: Lets assume you have a RS485 bus and a IO-4 Bricklet 2.0 is connected to one of the slave stacks. You can now call this function every second, with a time parameter of two seconds. The channel will be high all the time. If now the RS485 connection is lost, the channel will turn low in at most two seconds.

BrickletIO4V2->get_monoflop($channel)
Parameters:$channel -- int
Return type:[bool, int, int]

Returns (for the given channel) 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.

The returned array contains the elements value, time and time_remaining.

BrickletIO4V2->get_edge_count($channel, $reset_counter)
Parameters:
  • $channel -- int
  • $reset_counter -- bool
Return type:

int

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

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

BrickletIO4V2->set_edge_count_configuration($channel, $edge_type, $debounce)
Parameters:
  • $channel -- int
  • $edge_type -- int
  • $debounce -- int
Return type:

undef

Configures the edge counter for a specific channel.

The edge type parameter configures if rising edges, falling edges or both are counted if the channel 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:

  • BrickletIO4V2->EDGE_TYPE_RISING = 0
  • BrickletIO4V2->EDGE_TYPE_FALLING = 1
  • BrickletIO4V2->EDGE_TYPE_BOTH = 2
BrickletIO4V2->get_edge_count_configuration($channel)
Parameters:$channel -- int
Return type:[int, int]

Returns the edge type and debounce time for the selected channel as set by set_edge_count_configuration().

The following constants are available for this function:

  • BrickletIO4V2->EDGE_TYPE_RISING = 0
  • BrickletIO4V2->EDGE_TYPE_FALLING = 1
  • BrickletIO4V2->EDGE_TYPE_BOTH = 2

The returned array contains the elements edge_type and debounce.

BrickletIO4V2->set_pwm_configuration($channel, $frequency, $duty_cycle)
Parameters:
  • $channel -- int
  • $frequency -- int
  • $duty_cycle -- int
Return type:

undef

Activates a PWM for the given channel with the frequency given in 1/10Hz and the duty cycle given in 1/100%.

You need to set the channel to output before you call this function, otherwise it will be ignored. To turn the PWM off again, you can set the frequency to 0 or any other function that changes a value of the channel (e.g. set_selected_value()).

The maximum frequency value is 320000000 (32MHz). The maximum duty cycle value is 10000 (100%).

The default values are 0, 0.

BrickletIO4V2->get_pwm_configuration($channel)
Parameters:$channel -- int
Return type:[int, int]

Returns the PWM configuration as set by set_pwm_configuration().

The returned array contains the elements frequency and duty_cycle.

BrickletIO4V2->get_api_version()
Return type:[int, int, int]

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.

BrickletIO4V2->get_response_expected($function_id)
Parameters:$function_id -- int
Return 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.

See set_response_expected() for the list of function ID constants available for this function.

BrickletIO4V2->set_response_expected($function_id, $response_expected)
Parameters:
  • $function_id -- int
  • $response_expected -- bool
Return type:

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 function ID constants are available for this function:

  • BrickletIO4V2->FUNCTION_SET_VALUE = 1
  • BrickletIO4V2->FUNCTION_SET_SELECTED_VALUE = 3
  • BrickletIO4V2->FUNCTION_SET_CONFIGURATION = 4
  • BrickletIO4V2->FUNCTION_SET_INPUT_VALUE_CALLBACK_CONFIGURATION = 6
  • BrickletIO4V2->FUNCTION_SET_ALL_INPUT_VALUE_CALLBACK_CONFIGURATION = 8
  • BrickletIO4V2->FUNCTION_SET_MONOFLOP = 10
  • BrickletIO4V2->FUNCTION_SET_EDGE_COUNT_CONFIGURATION = 13
  • BrickletIO4V2->FUNCTION_SET_PWM_CONFIGURATION = 15
  • BrickletIO4V2->FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
  • BrickletIO4V2->FUNCTION_SET_STATUS_LED_CONFIG = 239
  • BrickletIO4V2->FUNCTION_RESET = 243
  • BrickletIO4V2->FUNCTION_WRITE_UID = 248
BrickletIO4V2->set_response_expected_all($response_expected)
Parameters:$response_expected -- bool
Return type:undef

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

BrickletIO4V2->get_spitfp_error_count()
Return type:[int, int, int, int]

Returns the error count for the communication between Brick and Bricklet.

The errors are divided into

  • ACK checksum errors,
  • message checksum errors,
  • framing errors and
  • overflow errors.

The errors counts are for errors that occur on the Bricklet side. All Bricks have a similar function that returns the errors on the Brick side.

The returned array contains the elements error_count_ack_checksum, error_count_message_checksum, error_count_frame and error_count_overflow.

BrickletIO4V2->set_bootloader_mode($mode)
Parameters:$mode -- int
Return type:int

Sets the bootloader mode and returns the status after the requested mode change was instigated.

You can change from bootloader mode to firmware mode and vice versa. A change from bootloader mode to firmware mode will only take place if the entry function, device identifier and CRC are present and correct.

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

The following constants are available for this function:

  • BrickletIO4V2->BOOTLOADER_MODE_BOOTLOADER = 0
  • BrickletIO4V2->BOOTLOADER_MODE_FIRMWARE = 1
  • BrickletIO4V2->BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BrickletIO4V2->BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BrickletIO4V2->BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
  • BrickletIO4V2->BOOTLOADER_STATUS_OK = 0
  • BrickletIO4V2->BOOTLOADER_STATUS_INVALID_MODE = 1
  • BrickletIO4V2->BOOTLOADER_STATUS_NO_CHANGE = 2
  • BrickletIO4V2->BOOTLOADER_STATUS_ENTRY_FUNCTION_NOT_PRESENT = 3
  • BrickletIO4V2->BOOTLOADER_STATUS_DEVICE_IDENTIFIER_INCORRECT = 4
  • BrickletIO4V2->BOOTLOADER_STATUS_CRC_MISMATCH = 5
BrickletIO4V2->get_bootloader_mode()
Return type:int

Returns the current bootloader mode, see set_bootloader_mode().

The following constants are available for this function:

  • BrickletIO4V2->BOOTLOADER_MODE_BOOTLOADER = 0
  • BrickletIO4V2->BOOTLOADER_MODE_FIRMWARE = 1
  • BrickletIO4V2->BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BrickletIO4V2->BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BrickletIO4V2->BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
BrickletIO4V2->set_write_firmware_pointer($pointer)
Parameters:$pointer -- int
Return type:undef

Sets the firmware pointer for write_firmware(). The pointer has to be increased by chunks of size 64. The data is written to flash every 4 chunks (which equals to one page of size 256).

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

BrickletIO4V2->write_firmware(@data)
Parameters:@data -- [int, int, ..61x.., int]
Return type:int

Writes 64 Bytes of firmware at the position as written by set_write_firmware_pointer() before. The firmware is written to flash every 4 chunks.

You can only write firmware in bootloader mode.

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

BrickletIO4V2->set_status_led_config($config)
Parameters:$config -- int
Return type:undef

Sets the status LED configuration. By default the LED shows communication traffic between Brick and Bricklet, it flickers once for every 10 received data packets.

You can also turn the LED permanently on/off or show a heartbeat.

If the Bricklet is in bootloader mode, the LED is will show heartbeat by default.

The following constants are available for this function:

  • BrickletIO4V2->STATUS_LED_CONFIG_OFF = 0
  • BrickletIO4V2->STATUS_LED_CONFIG_ON = 1
  • BrickletIO4V2->STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BrickletIO4V2->STATUS_LED_CONFIG_SHOW_STATUS = 3
BrickletIO4V2->get_status_led_config()
Return type:int

Returns the configuration as set by set_status_led_config()

The following constants are available for this function:

  • BrickletIO4V2->STATUS_LED_CONFIG_OFF = 0
  • BrickletIO4V2->STATUS_LED_CONFIG_ON = 1
  • BrickletIO4V2->STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BrickletIO4V2->STATUS_LED_CONFIG_SHOW_STATUS = 3
BrickletIO4V2->get_chip_temperature()
Return type:int

Returns the temperature in °C as measured inside the microcontroller. The value returned is not the ambient temperature!

The temperature is only proportional to the real temperature and it has bad accuracy. Practically it is only useful as an indicator for temperature changes.

BrickletIO4V2->reset()
Return type:undef

Calling this function will reset the Bricklet. All configurations will be lost.

After a reset you have to create new device objects, calling functions on the existing ones will result in undefined behavior!

BrickletIO4V2->write_uid($uid)
Parameters:$uid -- int
Return type:undef

Writes a new UID into flash. If you want to set a new UID you have to decode the Base58 encoded UID string into an integer first.

We recommend that you use Brick Viewer to change the UID.

BrickletIO4V2->read_uid()
Return type:int

Returns the current UID as an integer. Encode as Base58 to get the usual string version.

BrickletIO4V2->get_identity()
Return type:[string, string, char, [int, int, int], [int, int, int], int]

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.

The returned array contains the elements uid, connected_uid, position, hardware_version, firmware_version and device_identifier.

Callback Configuration Functions

BrickletIO4V2->register_callback($id, $callback)
Parameters:
  • $id -- int
  • $callback -- string
Return type:

undef

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

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

BrickletIO4V2->get_configuration($channel)
Parameters:$channel -- int
Return type:[char, bool]

Returns the channel configuration as set by set_configuration().

The following constants are available for this function:

  • BrickletIO4V2->DIRECTION_IN = 'i'
  • BrickletIO4V2->DIRECTION_OUT = 'o'

The returned array contains the elements direction and value.

BrickletIO4V2->set_input_value_callback_configuration($channel, $period, $value_has_to_change)
Parameters:
  • $channel -- int
  • $period -- int
  • $value_has_to_change -- bool
Return type:

undef

This callback can be configured per channel.

The period in ms is the period with which the CALLBACK_INPUT_VALUE callback is triggered periodically. A value of 0 turns the callback off.

If the value has to change-parameter is set to true, the callback is only triggered after the value has changed. If the value didn't change within the period, the callback is triggered immediately on change.

If it is set to false, the callback is continuously triggered with the period, independent of the value.

The default value is (0, false).

BrickletIO4V2->get_input_value_callback_configuration($channel)
Parameters:$channel -- int
Return type:[int, bool]

Returns the callback configuration for the given channel as set by set_input_value_callback_configuration().

The returned array contains the elements period and value_has_to_change.

BrickletIO4V2->set_all_input_value_callback_configuration($period, $value_has_to_change)
Parameters:
  • $period -- int
  • $value_has_to_change -- bool
Return type:

undef

The period in ms is the period with which the CALLBACK_ALL_INPUT_VALUE callback is triggered periodically. A value of 0 turns the callback off.

If the value has to change-parameter is set to true, the callback is only triggered after the value has changed. If the value didn't change within the period, the callback is triggered immediately on change.

If it is set to false, the callback is continuously triggered with the period, independent of the value.

The default value is (0, false).

BrickletIO4V2->get_all_input_value_callback_configuration()
Return type:[int, bool]

Returns the callback configuration as set by set_all_input_value_callback_configuration().

The returned array contains the elements period and value_has_to_change.

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_v2->register_callback(BrickletIO4V2->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.

BrickletIO4V2->CALLBACK_INPUT_VALUE
Parameters:
  • $channel -- int
  • $changed -- bool
  • $value -- bool

This callback is triggered periodically according to the configuration set by set_input_value_callback_configuration().

The parameters are the channel, a value-changed indicator and the actual value for the channel. The changed parameter is true if the value has changed since the last callback.

BrickletIO4V2->CALLBACK_ALL_INPUT_VALUE
Parameters:
  • @changed -- [bool, bool, bool, bool]
  • @value -- [bool, bool, bool, bool]

This callback is triggered periodically according to the configuration set by set_all_input_value_callback_configuration().

The parameters are the same as get_value(). Additional the changed parameter is true if the value has changed since the last callback.

BrickletIO4V2->CALLBACK_MONOFLOP_DONE
Parameters:
  • $channel -- int
  • $value -- bool

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

Constants

BrickletIO4V2->DEVICE_IDENTIFIER

This constant is used to identify a IO-4 Bricklet 2.0.

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

BrickletIO4V2->DEVICE_DISPLAY_NAME

This constant represents the human readable name of a IO-4 Bricklet 2.0.