Perl - Air Quality Bricklet

This is the description of the Perl API bindings for the Air Quality Bricklet. General information and technical specifications for the Air Quality 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).

Simple

Download (example_simple.pl)

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#!/usr/bin/perl

use strict;
use Tinkerforge::IPConnection;
use Tinkerforge::BrickletAirQuality;

use constant HOST => 'localhost';
use constant PORT => 4223;
use constant UID => 'XYZ'; # Change XYZ to the UID of your Air Quality Bricklet

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

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

# Get current all values
my ($iaq_index, $iaq_index_accuracy, $temperature, $humidity, $air_pressure) = $aq->get_all_values();

print "IAQ Index: $iaq_index\n";

if ($iaq_index_accuracy == $aq->ACCURACY_UNRELIABLE)
{
    print "IAQ Index Accuracy: Unreliable\n";
}
elsif ($iaq_index_accuracy == $aq->ACCURACY_LOW)
{
    print "IAQ Index Accuracy: Low\n";
}
elsif ($iaq_index_accuracy == $aq->ACCURACY_MEDIUM)
{
    print "IAQ Index Accuracy: Medium\n";
}
elsif ($iaq_index_accuracy == $aq->ACCURACY_HIGH)
{
    print "IAQ Index Accuracy: High\n";
}

print "Temperature: " . $temperature/100.0 . " °C\n";
print "Humidity: " . $humidity/100.0 . " %RH\n";
print "Air Pressure: " . $air_pressure/100.0 . " hPa\n";

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

Callback

Download (example_callback.pl)

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#!/usr/bin/perl

use strict;
use Tinkerforge::IPConnection;
use Tinkerforge::BrickletAirQuality;

use constant HOST => 'localhost';
use constant PORT => 4223;
use constant UID => 'XYZ'; # Change XYZ to the UID of your Air Quality Bricklet

# Callback subroutine for all values callback
sub cb_all_values
{
    my ($iaq_index, $iaq_index_accuracy, $temperature, $humidity, $air_pressure) = @_;

    print "IAQ Index: $iaq_index\n";

    if ($iaq_index_accuracy == Tinkerforge::BrickletAirQuality->ACCURACY_UNRELIABLE)
    {
        print "IAQ Index Accuracy: Unreliable\n";
    }
    elsif ($iaq_index_accuracy == Tinkerforge::BrickletAirQuality->ACCURACY_LOW)
    {
        print "IAQ Index Accuracy: Low\n";
    }
    elsif ($iaq_index_accuracy == Tinkerforge::BrickletAirQuality->ACCURACY_MEDIUM)
    {
        print "IAQ Index Accuracy: Medium\n";
    }
    elsif ($iaq_index_accuracy == Tinkerforge::BrickletAirQuality->ACCURACY_HIGH)
    {
        print "IAQ Index Accuracy: High\n";
    }

    print "Temperature: " . $temperature/100.0 . " °C\n";
    print "Humidity: " . $humidity/100.0 . " %RH\n";
    print "Air Pressure: " . $air_pressure/100.0 . " hPa\n";
    print "\n";
}

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

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

# Register all values callback to subroutine cb_all_values
$aq->register_callback($aq->CALLBACK_ALL_VALUES, 'cb_all_values');

# Set period for all values callback to 1s (1000ms)
$aq->set_all_values_callback_configuration(1000, 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 functions listed below are thread-safe.

Basic Functions

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

Creates an object with the unique device ID $uid:

$air_quality = BrickletAirQuality->new("YOUR_DEVICE_UID", $ipcon);

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

BrickletAirQuality->get_all_values()
Return Array:
  • 0: $iaq_index – Type: int, Range: [0 to 500]
  • 1: $iaq_index_accuracy – Type: int, Range: See constants
  • 2: $temperature – Type: int, Unit: 1/100 °C, Range: [-231 to 231 - 1]
  • 3: $humidity – Type: int, Unit: 1/100 %, Range: [-231 to 231 - 1]
  • 4: $air_pressure – Type: int, Unit: 1/100 hPa, Range: [-231 to 231 - 1]

Returns all values measured by the Air Quality Bricklet. The values are IAQ (Indoor Air Quality) Index (higher value means greater level of air pollution), IAQ Index Accuracy, Temperature, Humidity and Air Pressure.

Air Quality Index description

The following constants are available for this function:

For $iaq_index_accuracy:

  • BrickletAirQuality->ACCURACY_UNRELIABLE = 0
  • BrickletAirQuality->ACCURACY_LOW = 1
  • BrickletAirQuality->ACCURACY_MEDIUM = 2
  • BrickletAirQuality->ACCURACY_HIGH = 3
BrickletAirQuality->set_temperature_offset($offset)
Parameters:
  • $offset – Type: int, Unit: 1/100 °C, Range: [-231 to 231 - 1]
Returns:
  • undef

Sets a temperature offset. A offset of 10 will decrease the measured temperature by 0.1 °C.

If you install this Bricklet into an enclosure and you want to measure the ambient temperature, you may have to decrease the measured temperature by some value to compensate for the error because of the heating inside of the enclosure.

We recommend that you leave the parts in the enclosure running for at least 24 hours such that a temperature equilibrium can be reached. After that you can measure the temperature directly outside of enclosure and set the difference as offset.

This temperature offset is used to calculate the relative humidity and IAQ index measurements. In case the Bricklet is installed in an enclosure, we recommend to measure and set the temperature offset to imporve the accuracy of the measurements.

BrickletAirQuality->get_temperature_offset()
Returns:
  • $offset – Type: int, Unit: 1/100 °C, Range: [-231 to 231 - 1]

Returns the temperature offset as set by set_temperature_offset().

BrickletAirQuality->get_iaq_index()
Return Array:
  • 0: $iaq_index – Type: int, Range: [0 to 500]
  • 1: $iaq_index_accuracy – Type: int, Range: See constants

Returns the IAQ index and accuracy. The higher the IAQ index, the greater the level of air pollution.

IAQ index description

If you want to get the value periodically, it is recommended to use the CALLBACK_IAQ_INDEX callback. You can set the callback configuration with set_iaq_index_callback_configuration().

The following constants are available for this function:

For $iaq_index_accuracy:

  • BrickletAirQuality->ACCURACY_UNRELIABLE = 0
  • BrickletAirQuality->ACCURACY_LOW = 1
  • BrickletAirQuality->ACCURACY_MEDIUM = 2
  • BrickletAirQuality->ACCURACY_HIGH = 3
BrickletAirQuality->get_temperature()
Returns:
  • $temperature – Type: int, Unit: 1/100 °C, Range: [-231 to 231 - 1]

Returns temperature.

If you want to get the value periodically, it is recommended to use the CALLBACK_TEMPERATURE callback. You can set the callback configuration with set_temperature_callback_configuration().

BrickletAirQuality->get_humidity()
Returns:
  • $humidity – Type: int, Unit: 1/100 %, Range: [-231 to 231 - 1]

Returns relative humidity.

If you want to get the value periodically, it is recommended to use the CALLBACK_HUMIDITY callback. You can set the callback configuration with set_humidity_callback_configuration().

BrickletAirQuality->get_air_pressure()
Returns:
  • $air_pressure – Type: int, Unit: 1/100 hPa, Range: [-231 to 231 - 1]

Returns air pressure.

If you want to get the value periodically, it is recommended to use the CALLBACK_AIR_PRESSURE callback. You can set the callback configuration with set_air_pressure_callback_configuration().

Advanced Functions

BrickletAirQuality->remove_calibration()
Returns:
  • undef

Deletes the calibration from flash. After you call this function, you need to power cycle the Air Quality Bricklet.

On the next power up the Bricklet will start a new calibration, as if it was started for the very first time.

The calibration is based on the data of the last four days, so it takes four days until a full calibration is re-established.

New in version 2.0.3 (Plugin).

BrickletAirQuality->set_background_calibration_duration($duration)
Parameters:
  • $duration – Type: int, Range: See constants, Default: 1
Returns:
  • undef

The Air Quality Bricklet uses an automatic background calibration mechanism to calculate the IAQ Index. This calibration mechanism considers a history of measured data. The duration of this history can be configured to either be 4 days or 28 days.

If you keep the Bricklet mostly at one place and it does not get moved around to different environments, we recommend that you use a duration of 28 days.

If you change the duration, the current calibration will be discarded and the calibration will start from beginning again. The configuration of the duration is saved in flash, so you should only have to call this function once in the lifetime of the Bricklet.

The Bricklet has to be power cycled after this function is called for a duration change to take effect.

Before firmware version 2.0.3 this was not configurable and the duration was 4 days.

The default value (since firmware version 2.0.3) is 28 days.

The following constants are available for this function:

For $duration:

  • BrickletAirQuality->DURATION_4_DAYS = 0
  • BrickletAirQuality->DURATION_28_DAYS = 1

New in version 2.0.3 (Plugin).

BrickletAirQuality->get_background_calibration_duration()
Returns:
  • $duration – Type: int, Range: See constants, Default: 1

Returns the background calibration duration as set by set_background_calibration_duration().

The following constants are available for this function:

For $duration:

  • BrickletAirQuality->DURATION_4_DAYS = 0
  • BrickletAirQuality->DURATION_28_DAYS = 1

New in version 2.0.3 (Plugin).

BrickletAirQuality->get_spitfp_error_count()
Return Array:
  • 0: $error_count_ack_checksum – Type: int, Range: [0 to 232 - 1]
  • 1: $error_count_message_checksum – Type: int, Range: [0 to 232 - 1]
  • 2: $error_count_frame – Type: int, Range: [0 to 232 - 1]
  • 3: $error_count_overflow – Type: int, Range: [0 to 232 - 1]

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.

BrickletAirQuality->set_bootloader_mode($mode)
Parameters:
  • $mode – Type: int, Range: See constants
Returns:
  • $status – Type: int, Range: See constants

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:

For $mode:

  • BrickletAirQuality->BOOTLOADER_MODE_BOOTLOADER = 0
  • BrickletAirQuality->BOOTLOADER_MODE_FIRMWARE = 1
  • BrickletAirQuality->BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BrickletAirQuality->BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BrickletAirQuality->BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4

For $status:

  • BrickletAirQuality->BOOTLOADER_STATUS_OK = 0
  • BrickletAirQuality->BOOTLOADER_STATUS_INVALID_MODE = 1
  • BrickletAirQuality->BOOTLOADER_STATUS_NO_CHANGE = 2
  • BrickletAirQuality->BOOTLOADER_STATUS_ENTRY_FUNCTION_NOT_PRESENT = 3
  • BrickletAirQuality->BOOTLOADER_STATUS_DEVICE_IDENTIFIER_INCORRECT = 4
  • BrickletAirQuality->BOOTLOADER_STATUS_CRC_MISMATCH = 5
BrickletAirQuality->get_bootloader_mode()
Returns:
  • $mode – Type: int, Range: See constants

Returns the current bootloader mode, see set_bootloader_mode().

The following constants are available for this function:

For $mode:

  • BrickletAirQuality->BOOTLOADER_MODE_BOOTLOADER = 0
  • BrickletAirQuality->BOOTLOADER_MODE_FIRMWARE = 1
  • BrickletAirQuality->BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BrickletAirQuality->BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BrickletAirQuality->BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
BrickletAirQuality->set_write_firmware_pointer($pointer)
Parameters:
  • $pointer – Type: int, Unit: 1 B, Range: [0 to 232 - 1]
Returns:
  • 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.

BrickletAirQuality->write_firmware(@data)
Parameters:
  • @data – Type: [int, ...], Length: 64, Range: [0 to 255]
Returns:
  • $status – Type: int, Range: [0 to 255]

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.

BrickletAirQuality->set_status_led_config($config)
Parameters:
  • $config – Type: int, Range: See constants, Default: 3
Returns:
  • 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:

For $config:

  • BrickletAirQuality->STATUS_LED_CONFIG_OFF = 0
  • BrickletAirQuality->STATUS_LED_CONFIG_ON = 1
  • BrickletAirQuality->STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BrickletAirQuality->STATUS_LED_CONFIG_SHOW_STATUS = 3
BrickletAirQuality->get_status_led_config()
Returns:
  • $config – Type: int, Range: See constants, Default: 3

Returns the configuration as set by set_status_led_config()

The following constants are available for this function:

For $config:

  • BrickletAirQuality->STATUS_LED_CONFIG_OFF = 0
  • BrickletAirQuality->STATUS_LED_CONFIG_ON = 1
  • BrickletAirQuality->STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BrickletAirQuality->STATUS_LED_CONFIG_SHOW_STATUS = 3
BrickletAirQuality->get_chip_temperature()
Returns:
  • $temperature – Type: int, Unit: 1 °C, Range: [-215 to 215 - 1]

Returns the temperature 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.

BrickletAirQuality->reset()
Returns:
  • 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!

BrickletAirQuality->write_uid($uid)
Parameters:
  • $uid – Type: int, Range: [0 to 232 - 1]
Returns:
  • 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.

BrickletAirQuality->read_uid()
Returns:
  • $uid – Type: int, Range: [0 to 232 - 1]

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

BrickletAirQuality->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, Range: ['a' to 'i', 'z']
  • 3: @hardware_version – Type: [int, ...], Length: 3
    • 0: $major – Type: int, Range: [0 to 255]
    • 1: $minor – Type: int, Range: [0 to 255]
    • 2: $revision – Type: int, Range: [0 to 255]
  • 4: @firmware_version – Type: [int, ...], Length: 3
    • 0: $major – Type: int, Range: [0 to 255]
    • 1: $minor – Type: int, Range: [0 to 255]
    • 2: $revision – Type: int, 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', 'd', 'e', 'f', 'g' or 'h' (Bricklet Port). The Raspberry Pi HAT (Zero) Brick is always at position 'i' and the Bricklet connected to an Isolator Bricklet is always as position 'z'.

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

Callback Configuration Functions

BrickletAirQuality->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.

BrickletAirQuality->set_all_values_callback_configuration($period, $value_has_to_change)
Parameters:
  • $period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
  • $value_has_to_change – Type: bool, Default: 0
Returns:
  • undef

The period is the period with which the CALLBACK_ALL_VALUES 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 at least one of the values has changed. If the values 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.

BrickletAirQuality->get_all_values_callback_configuration()
Return Array:
  • 0: $period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
  • 1: $value_has_to_change – Type: bool, Default: 0

Returns the callback configuration as set by set_all_values_callback_configuration().

BrickletAirQuality->set_iaq_index_callback_configuration($period, $value_has_to_change)
Parameters:
  • $period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
  • $value_has_to_change – Type: bool, Default: 0
Returns:
  • undef

The period is the period with which the CALLBACK_IAQ_INDEX 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 at least one of the values has changed. If the values 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.

BrickletAirQuality->get_iaq_index_callback_configuration()
Return Array:
  • 0: $period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
  • 1: $value_has_to_change – Type: bool, Default: 0

Returns the callback configuration as set by set_iaq_index_callback_configuration().

BrickletAirQuality->set_temperature_callback_configuration($period, $value_has_to_change, $option, $min, $max)
Parameters:
  • $period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
  • $value_has_to_change – Type: bool, Default: 0
  • $option – Type: char, Range: See constants, Default: 'x'
  • $min – Type: int, Unit: 1/100 °C, Range: [-231 to 231 - 1], Default: 0
  • $max – Type: int, Unit: 1/100 °C, Range: [-231 to 231 - 1], Default: 0
Returns:
  • undef

The period is the period with which the CALLBACK_TEMPERATURE 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.

It is furthermore possible to constrain the callback with thresholds.

The option-parameter together with min/max sets a threshold for the CALLBACK_TEMPERATURE callback.

The following options are possible:

Option Description
'x' Threshold is turned off
'o' Threshold is triggered when the value is outside the min and max values
'i' Threshold is triggered when the value is inside or equal to the min and max values
'<' Threshold is triggered when the value is smaller than the min value (max is ignored)
'>' Threshold is triggered when the value is greater than the min value (max is ignored)

If the option is set to 'x' (threshold turned off) the callback is triggered with the fixed period.

The following constants are available for this function:

For $option:

  • BrickletAirQuality->THRESHOLD_OPTION_OFF = 'x'
  • BrickletAirQuality->THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletAirQuality->THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletAirQuality->THRESHOLD_OPTION_SMALLER = '<'
  • BrickletAirQuality->THRESHOLD_OPTION_GREATER = '>'
BrickletAirQuality->get_temperature_callback_configuration()
Return Array:
  • 0: $period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
  • 1: $value_has_to_change – Type: bool, Default: 0
  • 2: $option – Type: char, Range: See constants, Default: 'x'
  • 3: $min – Type: int, Unit: 1/100 °C, Range: [-231 to 231 - 1], Default: 0
  • 4: $max – Type: int, Unit: 1/100 °C, Range: [-231 to 231 - 1], Default: 0

Returns the callback configuration as set by set_temperature_callback_configuration().

The following constants are available for this function:

For $option:

  • BrickletAirQuality->THRESHOLD_OPTION_OFF = 'x'
  • BrickletAirQuality->THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletAirQuality->THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletAirQuality->THRESHOLD_OPTION_SMALLER = '<'
  • BrickletAirQuality->THRESHOLD_OPTION_GREATER = '>'
BrickletAirQuality->set_humidity_callback_configuration($period, $value_has_to_change, $option, $min, $max)
Parameters:
  • $period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
  • $value_has_to_change – Type: bool, Default: 0
  • $option – Type: char, Range: See constants, Default: 'x'
  • $min – Type: int, Unit: 1/100 %, Range: [-231 to 231 - 1], Default: 0
  • $max – Type: int, Unit: 1/100 %, Range: [-231 to 231 - 1], Default: 0
Returns:
  • undef

The period is the period with which the CALLBACK_HUMIDITY 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.

It is furthermore possible to constrain the callback with thresholds.

The option-parameter together with min/max sets a threshold for the CALLBACK_HUMIDITY callback.

The following options are possible:

Option Description
'x' Threshold is turned off
'o' Threshold is triggered when the value is outside the min and max values
'i' Threshold is triggered when the value is inside or equal to the min and max values
'<' Threshold is triggered when the value is smaller than the min value (max is ignored)
'>' Threshold is triggered when the value is greater than the min value (max is ignored)

If the option is set to 'x' (threshold turned off) the callback is triggered with the fixed period.

The following constants are available for this function:

For $option:

  • BrickletAirQuality->THRESHOLD_OPTION_OFF = 'x'
  • BrickletAirQuality->THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletAirQuality->THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletAirQuality->THRESHOLD_OPTION_SMALLER = '<'
  • BrickletAirQuality->THRESHOLD_OPTION_GREATER = '>'
BrickletAirQuality->get_humidity_callback_configuration()
Return Array:
  • 0: $period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
  • 1: $value_has_to_change – Type: bool, Default: 0
  • 2: $option – Type: char, Range: See constants, Default: 'x'
  • 3: $min – Type: int, Unit: 1/100 %, Range: [-231 to 231 - 1], Default: 0
  • 4: $max – Type: int, Unit: 1/100 %, Range: [-231 to 231 - 1], Default: 0

Returns the callback configuration as set by set_humidity_callback_configuration().

The following constants are available for this function:

For $option:

  • BrickletAirQuality->THRESHOLD_OPTION_OFF = 'x'
  • BrickletAirQuality->THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletAirQuality->THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletAirQuality->THRESHOLD_OPTION_SMALLER = '<'
  • BrickletAirQuality->THRESHOLD_OPTION_GREATER = '>'
BrickletAirQuality->set_air_pressure_callback_configuration($period, $value_has_to_change, $option, $min, $max)
Parameters:
  • $period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
  • $value_has_to_change – Type: bool, Default: 0
  • $option – Type: char, Range: See constants, Default: 'x'
  • $min – Type: int, Unit: 1/100 hPa, Range: [-231 to 231 - 1], Default: 0
  • $max – Type: int, Unit: 1/100 hPa, Range: [-231 to 231 - 1], Default: 0
Returns:
  • undef

The period is the period with which the CALLBACK_AIR_PRESSURE 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.

It is furthermore possible to constrain the callback with thresholds.

The option-parameter together with min/max sets a threshold for the CALLBACK_AIR_PRESSURE callback.

The following options are possible:

Option Description
'x' Threshold is turned off
'o' Threshold is triggered when the value is outside the min and max values
'i' Threshold is triggered when the value is inside or equal to the min and max values
'<' Threshold is triggered when the value is smaller than the min value (max is ignored)
'>' Threshold is triggered when the value is greater than the min value (max is ignored)

If the option is set to 'x' (threshold turned off) the callback is triggered with the fixed period.

The following constants are available for this function:

For $option:

  • BrickletAirQuality->THRESHOLD_OPTION_OFF = 'x'
  • BrickletAirQuality->THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletAirQuality->THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletAirQuality->THRESHOLD_OPTION_SMALLER = '<'
  • BrickletAirQuality->THRESHOLD_OPTION_GREATER = '>'
BrickletAirQuality->get_air_pressure_callback_configuration()
Return Array:
  • 0: $period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
  • 1: $value_has_to_change – Type: bool, Default: 0
  • 2: $option – Type: char, Range: See constants, Default: 'x'
  • 3: $min – Type: int, Unit: 1/100 hPa, Range: [-231 to 231 - 1], Default: 0
  • 4: $max – Type: int, Unit: 1/100 hPa, Range: [-231 to 231 - 1], Default: 0

Returns the callback configuration as set by set_air_pressure_callback_configuration().

The following constants are available for this function:

For $option:

  • BrickletAirQuality->THRESHOLD_OPTION_OFF = 'x'
  • BrickletAirQuality->THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletAirQuality->THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletAirQuality->THRESHOLD_OPTION_SMALLER = '<'
  • BrickletAirQuality->THRESHOLD_OPTION_GREATER = '>'

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]";
}

$air_quality->register_callback(BrickletAirQuality->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.

BrickletAirQuality->CALLBACK_ALL_VALUES
Callback Parameters:
  • $iaq_index – Type: int, Range: [0 to 500]
  • $iaq_index_accuracy – Type: int, Range: See constants
  • $temperature – Type: int, Unit: 1/100 °C, Range: [-231 to 231 - 1]
  • $humidity – Type: int, Unit: 1/100 %, Range: [-231 to 231 - 1]
  • $air_pressure – Type: int, Unit: 1/100 hPa, Range: [-231 to 231 - 1]

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

The parameters are the same as get_all_values().

The following constants are available for this function:

For $iaq_index_accuracy:

  • BrickletAirQuality->ACCURACY_UNRELIABLE = 0
  • BrickletAirQuality->ACCURACY_LOW = 1
  • BrickletAirQuality->ACCURACY_MEDIUM = 2
  • BrickletAirQuality->ACCURACY_HIGH = 3
BrickletAirQuality->CALLBACK_IAQ_INDEX
Callback Parameters:
  • $iaq_index – Type: int, Range: [0 to 500]
  • $iaq_index_accuracy – Type: int, Range: See constants

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

The parameters are the same as get_iaq_index().

The following constants are available for this function:

For $iaq_index_accuracy:

  • BrickletAirQuality->ACCURACY_UNRELIABLE = 0
  • BrickletAirQuality->ACCURACY_LOW = 1
  • BrickletAirQuality->ACCURACY_MEDIUM = 2
  • BrickletAirQuality->ACCURACY_HIGH = 3
BrickletAirQuality->CALLBACK_TEMPERATURE
Callback Parameters:
  • $temperature – Type: int, Unit: 1/100 °C, Range: [-231 to 231 - 1]

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

The parameter is the same as get_temperature().

BrickletAirQuality->CALLBACK_HUMIDITY
Callback Parameters:
  • $humidity – Type: int, Unit: 1/100 %, Range: [-231 to 231 - 1]

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

The parameter is the same as get_humidity().

BrickletAirQuality->CALLBACK_AIR_PRESSURE
Callback Parameters:
  • $air_pressure – Type: int, Unit: 1/100 hPa, Range: [-231 to 231 - 1]

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

The parameter is the same as get_air_pressure().

Virtual Functions

Virtual functions don't communicate with the device itself, but operate only on the API bindings device object. They can be called without the corresponding IP Connection object being connected.

BrickletAirQuality->get_api_version()
Return Array:
  • 0: @api_version – Type: [int, ...], Length: 3
    • 0: $major – Type: int, Range: [0 to 255]
    • 1: $minor – Type: int, Range: [0 to 255]
    • 2: $revision – Type: int, Range: [0 to 255]

Returns the version of the API definition 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.

BrickletAirQuality->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:

  • BrickletAirQuality->FUNCTION_SET_TEMPERATURE_OFFSET = 2
  • BrickletAirQuality->FUNCTION_SET_ALL_VALUES_CALLBACK_CONFIGURATION = 4
  • BrickletAirQuality->FUNCTION_SET_IAQ_INDEX_CALLBACK_CONFIGURATION = 8
  • BrickletAirQuality->FUNCTION_SET_TEMPERATURE_CALLBACK_CONFIGURATION = 12
  • BrickletAirQuality->FUNCTION_SET_HUMIDITY_CALLBACK_CONFIGURATION = 16
  • BrickletAirQuality->FUNCTION_SET_AIR_PRESSURE_CALLBACK_CONFIGURATION = 20
  • BrickletAirQuality->FUNCTION_REMOVE_CALIBRATION = 23
  • BrickletAirQuality->FUNCTION_SET_BACKGROUND_CALIBRATION_DURATION = 24
  • BrickletAirQuality->FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
  • BrickletAirQuality->FUNCTION_SET_STATUS_LED_CONFIG = 239
  • BrickletAirQuality->FUNCTION_RESET = 243
  • BrickletAirQuality->FUNCTION_WRITE_UID = 248
BrickletAirQuality->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:

  • BrickletAirQuality->FUNCTION_SET_TEMPERATURE_OFFSET = 2
  • BrickletAirQuality->FUNCTION_SET_ALL_VALUES_CALLBACK_CONFIGURATION = 4
  • BrickletAirQuality->FUNCTION_SET_IAQ_INDEX_CALLBACK_CONFIGURATION = 8
  • BrickletAirQuality->FUNCTION_SET_TEMPERATURE_CALLBACK_CONFIGURATION = 12
  • BrickletAirQuality->FUNCTION_SET_HUMIDITY_CALLBACK_CONFIGURATION = 16
  • BrickletAirQuality->FUNCTION_SET_AIR_PRESSURE_CALLBACK_CONFIGURATION = 20
  • BrickletAirQuality->FUNCTION_REMOVE_CALIBRATION = 23
  • BrickletAirQuality->FUNCTION_SET_BACKGROUND_CALIBRATION_DURATION = 24
  • BrickletAirQuality->FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
  • BrickletAirQuality->FUNCTION_SET_STATUS_LED_CONFIG = 239
  • BrickletAirQuality->FUNCTION_RESET = 243
  • BrickletAirQuality->FUNCTION_WRITE_UID = 248
BrickletAirQuality->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.

Constants

BrickletAirQuality->DEVICE_IDENTIFIER

This constant is used to identify a Air Quality 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.

BrickletAirQuality->DEVICE_DISPLAY_NAME

This constant represents the human readable name of a Air Quality Bricklet.