Perl - Barometer Bricklet 2.0

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

Simple

Download (example_simple.pl)

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
#!/usr/bin/perl

use strict;
use Tinkerforge::IPConnection;
use Tinkerforge::BrickletBarometerV2;

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

my $ipcon = Tinkerforge::IPConnection->new(); # Create IP connection
my $b = Tinkerforge::BrickletBarometerV2->new(&UID, $ipcon); # Create device object

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

# Get current air pressure
my $air_pressure = $b->get_air_pressure();
print "Air Pressure: " . $air_pressure/1000.0 . " hPa\n";

# Get current altitude
my $altitude = $b->get_altitude();
print "Altitude: " . $altitude/1000.0 . " m\n";

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

Callback

Download (example_callback.pl)

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
#!/usr/bin/perl

use strict;
use Tinkerforge::IPConnection;
use Tinkerforge::BrickletBarometerV2;

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

# Callback subroutine for air pressure callback
sub cb_air_pressure
{
    my ($air_pressure) = @_;

    print "Air Pressure: " . $air_pressure/1000.0 . " hPa\n";
}

my $ipcon = Tinkerforge::IPConnection->new(); # Create IP connection
my $b = Tinkerforge::BrickletBarometerV2->new(&UID, $ipcon); # Create device object

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

# Register air pressure callback to subroutine cb_air_pressure
$b->register_callback($b->CALLBACK_AIR_PRESSURE, 'cb_air_pressure');

# Set period for air pressure callback to 1s (1000ms) without a threshold
$b->set_air_pressure_callback_configuration(1000, 0, 'x', 0, 0);

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

Threshold

Download (example_threshold.pl)

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
#!/usr/bin/perl

use strict;
use Tinkerforge::IPConnection;
use Tinkerforge::BrickletBarometerV2;

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

# Callback subroutine for air pressure callback
sub cb_air_pressure
{
    my ($air_pressure) = @_;

    print "Air Pressure: " . $air_pressure/1000.0 . " hPa\n";
    print "Enjoy the potentially good weather!\n";
}

my $ipcon = Tinkerforge::IPConnection->new(); # Create IP connection
my $b = Tinkerforge::BrickletBarometerV2->new(&UID, $ipcon); # Create device object

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

# Register air pressure callback to subroutine cb_air_pressure
$b->register_callback($b->CALLBACK_AIR_PRESSURE, 'cb_air_pressure');

# Configure threshold for air pressure "greater than 1025 hPa"
# with a debounce period of 1s (1000ms)
$b->set_air_pressure_callback_configuration(1000, 0, '>', 1025*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

BrickletBarometerV2->new($uid, $ipcon)
Parameters:
  • $uid – Type: string
  • $ipcon – Type: IPConnection
Returns:
  • $barometer_v2 – Type: BrickletBarometerV2

Creates an object with the unique device ID $uid:

$barometer_v2 = BrickletBarometerV2->new("YOUR_DEVICE_UID", $ipcon);

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

BrickletBarometerV2->get_air_pressure()
Returns:
  • $air_pressure – Type: int, Unit: 1/1000 hPa, Range: [260000 to 1260000]

Returns the measured 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().

BrickletBarometerV2->get_altitude()
Returns:
  • $altitude – Type: int, Unit: 1 mm, Range: [-231 to 231 - 1]

Returns the relative altitude of the air pressure sensor. The value is calculated based on the difference between the current air pressure and the reference air pressure that can be set with set_reference_air_pressure().

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

BrickletBarometerV2->get_temperature()
Returns:
  • $temperature – Type: int, Unit: 1/100 °C, Range: [-4000 to 8500]

Returns the temperature of the air pressure sensor.

This temperature is used internally for temperature compensation of the air pressure measurement. It is not as accurate as the temperature measured by the Temperature Bricklet 2.0 or the Temperature IR Bricklet 2.0.

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().

BrickletBarometerV2->set_moving_average_configuration($moving_average_length_air_pressure, $moving_average_length_temperature)
Parameters:
  • $moving_average_length_air_pressure – Type: int, Range: [1 to 1000], Default: 100
  • $moving_average_length_temperature – Type: int, Range: [1 to 1000], Default: 100
Returns:
  • undef

Sets the length of a moving averaging for the air pressure and temperature measurements.

Setting the length to 1 will turn the averaging off. With less averaging, there is more noise on the data.

If you want to do long term measurements the longest moving average will give the cleanest results.

BrickletBarometerV2->get_moving_average_configuration()
Return Array:
  • 0: $moving_average_length_air_pressure – Type: int, Range: [1 to 1000], Default: 100
  • 1: $moving_average_length_temperature – Type: int, Range: [1 to 1000], Default: 100

Returns the moving average configuration as set by set_moving_average_configuration().

BrickletBarometerV2->set_reference_air_pressure($air_pressure)
Parameters:
  • $air_pressure – Type: int, Unit: 1/1000 hPa, Range: [0, 260000 to 1260000], Default: 1013250
Returns:
  • undef

Sets the reference air pressure for the altitude calculation. Setting the reference to the current air pressure results in a calculated altitude of 0mm. Passing 0 is a shortcut for passing the current air pressure as reference.

Well known reference values are the Q codes QNH and QFE used in aviation.

BrickletBarometerV2->get_reference_air_pressure()
Returns:
  • $air_pressure – Type: int, Unit: 1/1000 hPa, Range: [260000 to 1260000], Default: 1013250

Returns the reference air pressure as set by set_reference_air_pressure().

Advanced Functions

BrickletBarometerV2->set_calibration($measured_air_pressure, $actual_air_pressure)
Parameters:
  • $measured_air_pressure – Type: int, Unit: 1/1000 hPa, Range: [0, 260000 to 1260000]
  • $actual_air_pressure – Type: int, Unit: 1/1000 hPa, Range: [0, 260000 to 1260000]
Returns:
  • undef

Sets the one point calibration (OPC) values for the air pressure measurement.

Before the Bricklet can be calibrated any previous calibration has to be removed by setting measured air pressure and actual air pressure to 0.

Then the current air pressure has to be measured using the Bricklet (measured air pressure) and with an accurate reference barometer (actual air pressure) at the same time and passed to this function.

After proper calibration the air pressure measurement can achieve an accuracy up to 0.2 hPa.

The calibration is saved in the EEPROM of the Bricklet and only needs to be configured once.

BrickletBarometerV2->get_calibration()
Return Array:
  • 0: $measured_air_pressure – Type: int, Unit: 1/1000 hPa, Range: [0, 260000 to 1260000]
  • 1: $actual_air_pressure – Type: int, Unit: 1/1000 hPa, Range: [0, 260000 to 1260000]

Returns the air pressure one point calibration values as set by set_calibration().

BrickletBarometerV2->set_sensor_configuration($data_rate, $air_pressure_low_pass_filter)
Parameters:
  • $data_rate – Type: int, Range: See constants, Default: 4
  • $air_pressure_low_pass_filter – Type: int, Range: See constants, Default: 1
Returns:
  • undef

Configures the data rate and air pressure low pass filter. The low pass filter cut-off frequency (if enabled) can be set to 1/9th or 1/20th of the configure data rate to decrease the noise on the air pressure data.

The low pass filter configuration only applies to the air pressure measurement. There is no low pass filter for the temperature measurement.

A higher data rate will result in a less precise temperature because of self-heating of the sensor. If the accuracy of the temperature reading is important to you, we would recommend the 1Hz data rate.

The following constants are available for this function:

For $data_rate:

  • BrickletBarometerV2->DATA_RATE_OFF = 0
  • BrickletBarometerV2->DATA_RATE_1HZ = 1
  • BrickletBarometerV2->DATA_RATE_10HZ = 2
  • BrickletBarometerV2->DATA_RATE_25HZ = 3
  • BrickletBarometerV2->DATA_RATE_50HZ = 4
  • BrickletBarometerV2->DATA_RATE_75HZ = 5

For $air_pressure_low_pass_filter:

  • BrickletBarometerV2->LOW_PASS_FILTER_OFF = 0
  • BrickletBarometerV2->LOW_PASS_FILTER_1_9TH = 1
  • BrickletBarometerV2->LOW_PASS_FILTER_1_20TH = 2
BrickletBarometerV2->get_sensor_configuration()
Return Array:
  • 0: $data_rate – Type: int, Range: See constants, Default: 4
  • 1: $air_pressure_low_pass_filter – Type: int, Range: See constants, Default: 1

Returns the sensor configuration as set by set_sensor_configuration().

The following constants are available for this function:

For $data_rate:

  • BrickletBarometerV2->DATA_RATE_OFF = 0
  • BrickletBarometerV2->DATA_RATE_1HZ = 1
  • BrickletBarometerV2->DATA_RATE_10HZ = 2
  • BrickletBarometerV2->DATA_RATE_25HZ = 3
  • BrickletBarometerV2->DATA_RATE_50HZ = 4
  • BrickletBarometerV2->DATA_RATE_75HZ = 5

For $air_pressure_low_pass_filter:

  • BrickletBarometerV2->LOW_PASS_FILTER_OFF = 0
  • BrickletBarometerV2->LOW_PASS_FILTER_1_9TH = 1
  • BrickletBarometerV2->LOW_PASS_FILTER_1_20TH = 2
BrickletBarometerV2->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.

BrickletBarometerV2->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:

  • BrickletBarometerV2->BOOTLOADER_MODE_BOOTLOADER = 0
  • BrickletBarometerV2->BOOTLOADER_MODE_FIRMWARE = 1
  • BrickletBarometerV2->BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BrickletBarometerV2->BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BrickletBarometerV2->BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4

For $status:

  • BrickletBarometerV2->BOOTLOADER_STATUS_OK = 0
  • BrickletBarometerV2->BOOTLOADER_STATUS_INVALID_MODE = 1
  • BrickletBarometerV2->BOOTLOADER_STATUS_NO_CHANGE = 2
  • BrickletBarometerV2->BOOTLOADER_STATUS_ENTRY_FUNCTION_NOT_PRESENT = 3
  • BrickletBarometerV2->BOOTLOADER_STATUS_DEVICE_IDENTIFIER_INCORRECT = 4
  • BrickletBarometerV2->BOOTLOADER_STATUS_CRC_MISMATCH = 5
BrickletBarometerV2->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:

  • BrickletBarometerV2->BOOTLOADER_MODE_BOOTLOADER = 0
  • BrickletBarometerV2->BOOTLOADER_MODE_FIRMWARE = 1
  • BrickletBarometerV2->BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2
  • BrickletBarometerV2->BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3
  • BrickletBarometerV2->BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4
BrickletBarometerV2->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.

BrickletBarometerV2->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.

BrickletBarometerV2->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:

  • BrickletBarometerV2->STATUS_LED_CONFIG_OFF = 0
  • BrickletBarometerV2->STATUS_LED_CONFIG_ON = 1
  • BrickletBarometerV2->STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BrickletBarometerV2->STATUS_LED_CONFIG_SHOW_STATUS = 3
BrickletBarometerV2->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:

  • BrickletBarometerV2->STATUS_LED_CONFIG_OFF = 0
  • BrickletBarometerV2->STATUS_LED_CONFIG_ON = 1
  • BrickletBarometerV2->STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2
  • BrickletBarometerV2->STATUS_LED_CONFIG_SHOW_STATUS = 3
BrickletBarometerV2->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.

BrickletBarometerV2->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!

BrickletBarometerV2->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.

BrickletBarometerV2->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.

BrickletBarometerV2->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 'h', '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

BrickletBarometerV2->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.

BrickletBarometerV2->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: 1/1000 hPa, Range: [-231 to 231 - 1], Default: 0
  • $max – Type: int, Unit: 1/1000 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:

  • BrickletBarometerV2->THRESHOLD_OPTION_OFF = 'x'
  • BrickletBarometerV2->THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletBarometerV2->THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletBarometerV2->THRESHOLD_OPTION_SMALLER = '<'
  • BrickletBarometerV2->THRESHOLD_OPTION_GREATER = '>'
BrickletBarometerV2->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: 1/1000 hPa, Range: [-231 to 231 - 1], Default: 0
  • 4: $max – Type: int, Unit: 1/1000 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:

  • BrickletBarometerV2->THRESHOLD_OPTION_OFF = 'x'
  • BrickletBarometerV2->THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletBarometerV2->THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletBarometerV2->THRESHOLD_OPTION_SMALLER = '<'
  • BrickletBarometerV2->THRESHOLD_OPTION_GREATER = '>'
BrickletBarometerV2->set_altitude_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 mm, Range: [-231 to 231 - 1], Default: 0
  • $max – Type: int, Unit: 1 mm, Range: [-231 to 231 - 1], Default: 0
Returns:
  • undef

The period is the period with which the CALLBACK_ALTITUDE 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_ALTITUDE 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:

  • BrickletBarometerV2->THRESHOLD_OPTION_OFF = 'x'
  • BrickletBarometerV2->THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletBarometerV2->THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletBarometerV2->THRESHOLD_OPTION_SMALLER = '<'
  • BrickletBarometerV2->THRESHOLD_OPTION_GREATER = '>'
BrickletBarometerV2->get_altitude_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 mm, Range: [-231 to 231 - 1], Default: 0
  • 4: $max – Type: int, Unit: 1 mm, Range: [-231 to 231 - 1], Default: 0

Returns the callback configuration as set by set_altitude_callback_configuration().

The following constants are available for this function:

For $option:

  • BrickletBarometerV2->THRESHOLD_OPTION_OFF = 'x'
  • BrickletBarometerV2->THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletBarometerV2->THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletBarometerV2->THRESHOLD_OPTION_SMALLER = '<'
  • BrickletBarometerV2->THRESHOLD_OPTION_GREATER = '>'
BrickletBarometerV2->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:

  • BrickletBarometerV2->THRESHOLD_OPTION_OFF = 'x'
  • BrickletBarometerV2->THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletBarometerV2->THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletBarometerV2->THRESHOLD_OPTION_SMALLER = '<'
  • BrickletBarometerV2->THRESHOLD_OPTION_GREATER = '>'
BrickletBarometerV2->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:

  • BrickletBarometerV2->THRESHOLD_OPTION_OFF = 'x'
  • BrickletBarometerV2->THRESHOLD_OPTION_OUTSIDE = 'o'
  • BrickletBarometerV2->THRESHOLD_OPTION_INSIDE = 'i'
  • BrickletBarometerV2->THRESHOLD_OPTION_SMALLER = '<'
  • BrickletBarometerV2->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]";
}

$barometer_v2->register_callback(BrickletBarometerV2->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.

BrickletBarometerV2->CALLBACK_AIR_PRESSURE
Callback Parameters:
  • $air_pressure – Type: int, Unit: 1/1000 hPa, Range: [260000 to 1260000]

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().

BrickletBarometerV2->CALLBACK_ALTITUDE
Callback Parameters:
  • $altitude – Type: int, Unit: 1 mm, Range: [-231 to 231 - 1]

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

The parameter is the same as get_altitude().

BrickletBarometerV2->CALLBACK_TEMPERATURE
Callback Parameters:
  • $temperature – Type: int, Unit: 1/100 °C, Range: [-4000 to 8500]

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

The parameter is the same as get_temperature().

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.

BrickletBarometerV2->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.

BrickletBarometerV2->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:

  • BrickletBarometerV2->FUNCTION_SET_AIR_PRESSURE_CALLBACK_CONFIGURATION = 2
  • BrickletBarometerV2->FUNCTION_SET_ALTITUDE_CALLBACK_CONFIGURATION = 6
  • BrickletBarometerV2->FUNCTION_SET_TEMPERATURE_CALLBACK_CONFIGURATION = 10
  • BrickletBarometerV2->FUNCTION_SET_MOVING_AVERAGE_CONFIGURATION = 13
  • BrickletBarometerV2->FUNCTION_SET_REFERENCE_AIR_PRESSURE = 15
  • BrickletBarometerV2->FUNCTION_SET_CALIBRATION = 17
  • BrickletBarometerV2->FUNCTION_SET_SENSOR_CONFIGURATION = 19
  • BrickletBarometerV2->FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
  • BrickletBarometerV2->FUNCTION_SET_STATUS_LED_CONFIG = 239
  • BrickletBarometerV2->FUNCTION_RESET = 243
  • BrickletBarometerV2->FUNCTION_WRITE_UID = 248
BrickletBarometerV2->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:

  • BrickletBarometerV2->FUNCTION_SET_AIR_PRESSURE_CALLBACK_CONFIGURATION = 2
  • BrickletBarometerV2->FUNCTION_SET_ALTITUDE_CALLBACK_CONFIGURATION = 6
  • BrickletBarometerV2->FUNCTION_SET_TEMPERATURE_CALLBACK_CONFIGURATION = 10
  • BrickletBarometerV2->FUNCTION_SET_MOVING_AVERAGE_CONFIGURATION = 13
  • BrickletBarometerV2->FUNCTION_SET_REFERENCE_AIR_PRESSURE = 15
  • BrickletBarometerV2->FUNCTION_SET_CALIBRATION = 17
  • BrickletBarometerV2->FUNCTION_SET_SENSOR_CONFIGURATION = 19
  • BrickletBarometerV2->FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237
  • BrickletBarometerV2->FUNCTION_SET_STATUS_LED_CONFIG = 239
  • BrickletBarometerV2->FUNCTION_RESET = 243
  • BrickletBarometerV2->FUNCTION_WRITE_UID = 248
BrickletBarometerV2->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

BrickletBarometerV2->DEVICE_IDENTIFIER

This constant is used to identify a Barometer Bricklet 2.0.

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.

BrickletBarometerV2->DEVICE_DISPLAY_NAME

This constant represents the human readable name of a Barometer Bricklet 2.0.