Perl - IMU Brick 2.0

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

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#!/usr/bin/perl

use strict;
use Tinkerforge::IPConnection;
use Tinkerforge::BrickIMUV2;

use constant HOST => 'localhost';
use constant PORT => 4223;
use constant UID => 'XXYYZZ'; # Change XXYYZZ to the UID of your IMU Brick 2.0

my $ipcon = Tinkerforge::IPConnection->new(); # Create IP connection
my $imu = Tinkerforge::BrickIMUV2->new(&UID, $ipcon); # Create device object

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

# Get current quaternion
my ($w, $x, $y, $z) = $imu->get_quaternion();

print "Quaternion [W]: " . $w/16383.0 . "\n";
print "Quaternion [X]: " . $x/16383.0 . "\n";
print "Quaternion [Y]: " . $y/16383.0 . "\n";
print "Quaternion [Z]: " . $z/16383.0 . "\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::BrickIMUV2;

use constant HOST => 'localhost';
use constant PORT => 4223;
use constant UID => 'XXYYZZ'; # Change XXYYZZ to the UID of your IMU Brick 2.0

# Callback subroutine for quaternion callback
sub cb_quaternion
{
    my ($w, $x, $y, $z) = @_;

    print "Quaternion [W]: " . $w/16383.0 . "\n";
    print "Quaternion [X]: " . $x/16383.0 . "\n";
    print "Quaternion [Y]: " . $y/16383.0 . "\n";
    print "Quaternion [Z]: " . $z/16383.0 . "\n";
    print "\n";
}

my $ipcon = Tinkerforge::IPConnection->new(); # Create IP connection
my $imu = Tinkerforge::BrickIMUV2->new(&UID, $ipcon); # Create device object

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

# Register quaternion callback to subroutine cb_quaternion
$imu->register_callback($imu->CALLBACK_QUATERNION, 'cb_quaternion');

# Set period for quaternion callback to 0.1s (100ms)
$imu->set_quaternion_period(100);

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

All Data

Download (example_all_data.pl)

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#!/usr/bin/perl

use strict;
use Tinkerforge::IPConnection;
use Tinkerforge::BrickIMUV2;

use constant HOST => 'localhost';
use constant PORT => 4223;
use constant UID => 'XXYYZZ'; # Change XXYYZZ to the UID of your IMU Brick 2.0

# Callback subroutine for all data callback
sub cb_all_data
{
    my ($acceleration, $magnetic_field, $angular_velocity, $euler_angle, $quaternion,
        $linear_acceleration, $gravity_vector, $temperature, $calibration_status) = @_;

    print "Acceleration [X]: " . @{$acceleration}[0]/100.0 . " m/s²\n";
    print "Acceleration [Y]: " . @{$acceleration}[1]/100.0 . " m/s²\n";
    print "Acceleration [Z]: " . @{$acceleration}[2]/100.0 . " m/s²\n";
    print "Magnetic Field [X]: " . @{$magnetic_field}[0]/16.0 . " µT\n";
    print "Magnetic Field [Y]: " . @{$magnetic_field}[1]/16.0 . " µT\n";
    print "Magnetic Field [Z]: " . @{$magnetic_field}[2]/16.0 . " µT\n";
    print "Angular Velocity [X]: " . @{$angular_velocity}[0]/16.0 . " °/s\n";
    print "Angular Velocity [Y]: " . @{$angular_velocity}[1]/16.0 . " °/s\n";
    print "Angular Velocity [Z]: " . @{$angular_velocity}[2]/16.0 . " °/s\n";
    print "Euler Angle [X]: " . @{$euler_angle}[0]/16.0 . " °\n";
    print "Euler Angle [Y]: " . @{$euler_angle}[1]/16.0 . " °\n";
    print "Euler Angle [Z]: " . @{$euler_angle}[2]/16.0 . " °\n";
    print "Quaternion [W]: " . @{$quaternion}[0]/16383.0 . "\n";
    print "Quaternion [X]: " . @{$quaternion}[1]/16383.0 . "\n";
    print "Quaternion [Y]: " . @{$quaternion}[2]/16383.0 . "\n";
    print "Quaternion [Z]: " . @{$quaternion}[3]/16383.0 . "\n";
    print "Linear Acceleration [X]: " . @{$linear_acceleration}[0]/100.0 . " m/s²\n";
    print "Linear Acceleration [Y]: " . @{$linear_acceleration}[1]/100.0 . " m/s²\n";
    print "Linear Acceleration [Z]: " . @{$linear_acceleration}[2]/100.0 . " m/s²\n";
    print "Gravity Vector [X]: " . @{$gravity_vector}[0]/100.0 . " m/s²\n";
    print "Gravity Vector [Y]: " . @{$gravity_vector}[1]/100.0 . " m/s²\n";
    print "Gravity Vector [Z]: " . @{$gravity_vector}[2]/100.0 . " m/s²\n";
    print "Temperature: $temperature °C\n";
    print "Calibration Status: " . sprintf('%08b', $calibration_status) . "\n";
    print "\n";
}

my $ipcon = Tinkerforge::IPConnection->new(); # Create IP connection
my $imu = Tinkerforge::BrickIMUV2->new(&UID, $ipcon); # Create device object

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

# Register all data callback to subroutine cb_all_data
$imu->register_callback($imu->CALLBACK_ALL_DATA, 'cb_all_data');

# Set period for all data callback to 0.1s (100ms)
$imu->set_all_data_period(100);

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

BrickIMUV2->new($uid, $ipcon)
Parameters:
  • $uid -- string
  • $ipcon -- IPConnection
Return type:

BrickIMUV2

Creates an object with the unique device ID $uid:

$imu_v2 = BrickIMUV2->new("YOUR_DEVICE_UID", $ipcon);

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

BrickIMUV2->get_orientation()
Return type:[int, int, int]

Returns the current orientation (heading, roll, pitch) of the IMU Brick as independent Euler angles in 1/16 degree. Note that Euler angles always experience a gimbal lock. We recommend that you use quaternions instead, if you need the absolute orientation.

The rotation angle has the following ranges:

  • heading: 0° to 360°
  • roll: -90° to +90°
  • pitch: -180° to +180°

If you want to get the orientation periodically, it is recommended to use the CALLBACK_ORIENTATION callback and set the period with set_orientation_period().

The returned array contains the elements heading, roll and pitch.

BrickIMUV2->get_linear_acceleration()
Return type:[int, int, int]

Returns the linear acceleration of the IMU Brick for the x, y and z axis in 1/100 m/s².

The linear acceleration is the acceleration in each of the three axis of the IMU Brick with the influences of gravity removed.

It is also possible to get the gravity vector with the influence of linear acceleration removed, see get_gravity_vector().

If you want to get the linear acceleration periodically, it is recommended to use the CALLBACK_LINEAR_ACCELERATION callback and set the period with set_linear_acceleration_period().

The returned array contains the elements x, y and z.

BrickIMUV2->get_gravity_vector()
Return type:[int, int, int]

Returns the current gravity vector of the IMU Brick for the x, y and z axis in 1/100 m/s².

The gravity vector is the acceleration that occurs due to gravity. Influences of additional linear acceleration are removed.

It is also possible to get the linear acceleration with the influence of gravity removed, see get_linear_acceleration().

If you want to get the gravity vector periodically, it is recommended to use the CALLBACK_GRAVITY_VECTOR callback and set the period with set_gravity_vector_period().

The returned array contains the elements x, y and z.

BrickIMUV2->get_quaternion()
Return type:[int, int, int, int]

Returns the current orientation (w, x, y, z) of the IMU Brick as quaternions.

You have to divide the returns values by 16383 (14 bit) to get the usual range of -1.0 to +1.0 for quaternions.

If you want to get the quaternions periodically, it is recommended to use the CALLBACK_QUATERNION callback and set the period with set_quaternion_period().

The returned array contains the elements w, x, y and z.

BrickIMUV2->get_all_data()
Return type:[[int, int, int], [int, int, int], [int, int, int], [int, int, int], [int, int, int, int], [int, int, int], [int, int, int], int, int]

Return all of the available data of the IMU Brick.

The calibration status consists of four pairs of two bits. Each pair of bits represents the status of the current calibration.

  • bit 0-1: Magnetometer
  • bit 2-3: Accelerometer
  • bit 4-5: Gyroscope
  • bit 6-7: System

A value of 0 means for "not calibrated" and a value of 3 means "fully calibrated". In your program you should always be able to ignore the calibration status, it is used by the calibration window of the Brick Viewer and it can be ignored after the first calibration. See the documentation in the calibration window for more information regarding the calibration of the IMU Brick.

If you want to get the data periodically, it is recommended to use the CALLBACK_ALL_DATA callback and set the period with set_all_data_period().

The returned array contains the elements acceleration, magnetic_field, angular_velocity, euler_angle, quaternion, linear_acceleration, gravity_vector, temperature and calibration_status.

BrickIMUV2->leds_on()
Return type:undef

Turns the orientation and direction LEDs of the IMU Brick on.

BrickIMUV2->leds_off()
Return type:undef

Turns the orientation and direction LEDs of the IMU Brick off.

BrickIMUV2->are_leds_on()
Return type:bool

Returns true if the orientation and direction LEDs of the IMU Brick are on, false otherwise.

Advanced Functions

BrickIMUV2->get_acceleration()
Return type:[int, int, int]

Returns the calibrated acceleration from the accelerometer for the x, y and z axis in 1/100 m/s².

If you want to get the acceleration periodically, it is recommended to use the CALLBACK_ACCELERATION callback and set the period with set_acceleration_period().

The returned array contains the elements x, y and z.

BrickIMUV2->get_magnetic_field()
Return type:[int, int, int]

Returns the calibrated magnetic field from the magnetometer for the x, y and z axis in 1/16 µT (Microtesla).

If you want to get the magnetic field periodically, it is recommended to use the CALLBACK_MAGNETIC_FIELD callback and set the period with set_magnetic_field_period().

The returned array contains the elements x, y and z.

BrickIMUV2->get_angular_velocity()
Return type:[int, int, int]

Returns the calibrated angular velocity from the gyroscope for the x, y and z axis in 1/16 °/s.

If you want to get the angular velocity periodically, it is recommended to use the CALLBACK_ANGULAR_VELOCITY acallback nd set the period with set_angular_velocity_period().

The returned array contains the elements x, y and z.

BrickIMUV2->get_temperature()
Return type:int

Returns the temperature of the IMU Brick. The temperature is given in °C. The temperature is measured in the core of the BNO055 IC, it is not the ambient temperature

BrickIMUV2->save_calibration()
Return type:bool

A call of this function saves the current calibration to be used as a starting point for the next restart of continuous calibration of the IMU Brick.

A return value of true means that the calibration could be used and false means that it could not be used (this happens if the calibration status is not "fully calibrated").

This function is used by the calibration window of the Brick Viewer, you should not need to call it in your program.

BrickIMUV2->set_sensor_configuration($magnetometer_rate, $gyroscope_range, $gyroscope_bandwidth, $accelerometer_range, $accelerometer_bandwidth)
Parameters:
  • $magnetometer_rate -- int
  • $gyroscope_range -- int
  • $gyroscope_bandwidth -- int
  • $accelerometer_range -- int
  • $accelerometer_bandwidth -- int
Return type:

undef

Sets the available sensor configuration for the Magnetometer, Gyroscope and Accelerometer. The Accelerometer Range is user selectable in all fusion modes, all other configurations are auto-controlled in fusion mode.

The default values are:

  • Magnetometer Rate 20Hz
  • Gyroscope Range 2000°/s
  • Gyroscope Bandwidth 32Hz
  • Accelerometer Range +/-4G
  • Accelerometer Bandwidth 62.5Hz

The following constants are available for this function:

  • BrickIMUV2->MAGNETOMETER_RATE_2HZ = 0
  • BrickIMUV2->MAGNETOMETER_RATE_6HZ = 1
  • BrickIMUV2->MAGNETOMETER_RATE_8HZ = 2
  • BrickIMUV2->MAGNETOMETER_RATE_10HZ = 3
  • BrickIMUV2->MAGNETOMETER_RATE_15HZ = 4
  • BrickIMUV2->MAGNETOMETER_RATE_20HZ = 5
  • BrickIMUV2->MAGNETOMETER_RATE_25HZ = 6
  • BrickIMUV2->MAGNETOMETER_RATE_30HZ = 7
  • BrickIMUV2->GYROSCOPE_RANGE_2000DPS = 0
  • BrickIMUV2->GYROSCOPE_RANGE_1000DPS = 1
  • BrickIMUV2->GYROSCOPE_RANGE_500DPS = 2
  • BrickIMUV2->GYROSCOPE_RANGE_250DPS = 3
  • BrickIMUV2->GYROSCOPE_RANGE_125DPS = 4
  • BrickIMUV2->GYROSCOPE_BANDWIDTH_523HZ = 0
  • BrickIMUV2->GYROSCOPE_BANDWIDTH_230HZ = 1
  • BrickIMUV2->GYROSCOPE_BANDWIDTH_116HZ = 2
  • BrickIMUV2->GYROSCOPE_BANDWIDTH_47HZ = 3
  • BrickIMUV2->GYROSCOPE_BANDWIDTH_23HZ = 4
  • BrickIMUV2->GYROSCOPE_BANDWIDTH_12HZ = 5
  • BrickIMUV2->GYROSCOPE_BANDWIDTH_64HZ = 6
  • BrickIMUV2->GYROSCOPE_BANDWIDTH_32HZ = 7
  • BrickIMUV2->ACCELEROMETER_RANGE_2G = 0
  • BrickIMUV2->ACCELEROMETER_RANGE_4G = 1
  • BrickIMUV2->ACCELEROMETER_RANGE_8G = 2
  • BrickIMUV2->ACCELEROMETER_RANGE_16G = 3
  • BrickIMUV2->ACCELEROMETER_BANDWIDTH_7_81HZ = 0
  • BrickIMUV2->ACCELEROMETER_BANDWIDTH_15_63HZ = 1
  • BrickIMUV2->ACCELEROMETER_BANDWIDTH_31_25HZ = 2
  • BrickIMUV2->ACCELEROMETER_BANDWIDTH_62_5HZ = 3
  • BrickIMUV2->ACCELEROMETER_BANDWIDTH_125HZ = 4
  • BrickIMUV2->ACCELEROMETER_BANDWIDTH_250HZ = 5
  • BrickIMUV2->ACCELEROMETER_BANDWIDTH_500HZ = 6
  • BrickIMUV2->ACCELEROMETER_BANDWIDTH_1000HZ = 7

New in version 2.0.5 (Firmware).

BrickIMUV2->get_sensor_configuration()
Return type:[int, int, int, int, int]

Returns the sensor configuration as set by set_sensor_configuration().

The following constants are available for this function:

  • BrickIMUV2->MAGNETOMETER_RATE_2HZ = 0
  • BrickIMUV2->MAGNETOMETER_RATE_6HZ = 1
  • BrickIMUV2->MAGNETOMETER_RATE_8HZ = 2
  • BrickIMUV2->MAGNETOMETER_RATE_10HZ = 3
  • BrickIMUV2->MAGNETOMETER_RATE_15HZ = 4
  • BrickIMUV2->MAGNETOMETER_RATE_20HZ = 5
  • BrickIMUV2->MAGNETOMETER_RATE_25HZ = 6
  • BrickIMUV2->MAGNETOMETER_RATE_30HZ = 7
  • BrickIMUV2->GYROSCOPE_RANGE_2000DPS = 0
  • BrickIMUV2->GYROSCOPE_RANGE_1000DPS = 1
  • BrickIMUV2->GYROSCOPE_RANGE_500DPS = 2
  • BrickIMUV2->GYROSCOPE_RANGE_250DPS = 3
  • BrickIMUV2->GYROSCOPE_RANGE_125DPS = 4
  • BrickIMUV2->GYROSCOPE_BANDWIDTH_523HZ = 0
  • BrickIMUV2->GYROSCOPE_BANDWIDTH_230HZ = 1
  • BrickIMUV2->GYROSCOPE_BANDWIDTH_116HZ = 2
  • BrickIMUV2->GYROSCOPE_BANDWIDTH_47HZ = 3
  • BrickIMUV2->GYROSCOPE_BANDWIDTH_23HZ = 4
  • BrickIMUV2->GYROSCOPE_BANDWIDTH_12HZ = 5
  • BrickIMUV2->GYROSCOPE_BANDWIDTH_64HZ = 6
  • BrickIMUV2->GYROSCOPE_BANDWIDTH_32HZ = 7
  • BrickIMUV2->ACCELEROMETER_RANGE_2G = 0
  • BrickIMUV2->ACCELEROMETER_RANGE_4G = 1
  • BrickIMUV2->ACCELEROMETER_RANGE_8G = 2
  • BrickIMUV2->ACCELEROMETER_RANGE_16G = 3
  • BrickIMUV2->ACCELEROMETER_BANDWIDTH_7_81HZ = 0
  • BrickIMUV2->ACCELEROMETER_BANDWIDTH_15_63HZ = 1
  • BrickIMUV2->ACCELEROMETER_BANDWIDTH_31_25HZ = 2
  • BrickIMUV2->ACCELEROMETER_BANDWIDTH_62_5HZ = 3
  • BrickIMUV2->ACCELEROMETER_BANDWIDTH_125HZ = 4
  • BrickIMUV2->ACCELEROMETER_BANDWIDTH_250HZ = 5
  • BrickIMUV2->ACCELEROMETER_BANDWIDTH_500HZ = 6
  • BrickIMUV2->ACCELEROMETER_BANDWIDTH_1000HZ = 7

New in version 2.0.5 (Firmware).

The returned array contains the elements magnetometer_rate, gyroscope_range, gyroscope_bandwidth, accelerometer_range and accelerometer_bandwidth.

BrickIMUV2->set_sensor_fusion_mode($mode)
Parameters:$mode -- int
Return type:undef

If the fusion mode is turned off, the functions get_acceleration(), get_magnetic_field() and get_angular_velocity() return uncalibrated and uncompensated sensor data. All other sensor data getters return no data.

Since firmware version 2.0.6 you can also use a fusion mode without magnetometer. In this mode the calculated orientation is relative (with magnetometer it is absolute with respect to the earth). However, the calculation can't be influenced by spurious magnetic fields.

Since firmware version 2.0.13 you can also use a fusion mode without fast magnetometer calibration. This mode is the same as the normal fusion mode, but the fast magnetometer calibration is turned off. So to find the orientation the first time will likely take longer, but small magnetic influences might not affect the automatic calibration as much.

By default sensor fusion is on.

The following constants are available for this function:

  • BrickIMUV2->SENSOR_FUSION_OFF = 0
  • BrickIMUV2->SENSOR_FUSION_ON = 1
  • BrickIMUV2->SENSOR_FUSION_ON_WITHOUT_MAGNETOMETER = 2
  • BrickIMUV2->SENSOR_FUSION_ON_WITHOUT_FAST_MAGNETOMETER_CALIBRATION = 3

New in version 2.0.5 (Firmware).

BrickIMUV2->get_sensor_fusion_mode()
Return type:int

Returns the sensor fusion mode as set by set_sensor_fusion_mode().

The following constants are available for this function:

  • BrickIMUV2->SENSOR_FUSION_OFF = 0
  • BrickIMUV2->SENSOR_FUSION_ON = 1
  • BrickIMUV2->SENSOR_FUSION_ON_WITHOUT_MAGNETOMETER = 2
  • BrickIMUV2->SENSOR_FUSION_ON_WITHOUT_FAST_MAGNETOMETER_CALIBRATION = 3

New in version 2.0.5 (Firmware).

BrickIMUV2->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.

BrickIMUV2->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.

BrickIMUV2->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:

  • BrickIMUV2->FUNCTION_LEDS_ON = 10
  • BrickIMUV2->FUNCTION_LEDS_OFF = 11
  • BrickIMUV2->FUNCTION_SET_ACCELERATION_PERIOD = 14
  • BrickIMUV2->FUNCTION_SET_MAGNETIC_FIELD_PERIOD = 16
  • BrickIMUV2->FUNCTION_SET_ANGULAR_VELOCITY_PERIOD = 18
  • BrickIMUV2->FUNCTION_SET_TEMPERATURE_PERIOD = 20
  • BrickIMUV2->FUNCTION_SET_ORIENTATION_PERIOD = 22
  • BrickIMUV2->FUNCTION_SET_LINEAR_ACCELERATION_PERIOD = 24
  • BrickIMUV2->FUNCTION_SET_GRAVITY_VECTOR_PERIOD = 26
  • BrickIMUV2->FUNCTION_SET_QUATERNION_PERIOD = 28
  • BrickIMUV2->FUNCTION_SET_ALL_DATA_PERIOD = 30
  • BrickIMUV2->FUNCTION_SET_SENSOR_CONFIGURATION = 41
  • BrickIMUV2->FUNCTION_SET_SENSOR_FUSION_MODE = 43
  • BrickIMUV2->FUNCTION_SET_SPITFP_BAUDRATE_CONFIG = 231
  • BrickIMUV2->FUNCTION_SET_SPITFP_BAUDRATE = 234
  • BrickIMUV2->FUNCTION_ENABLE_STATUS_LED = 238
  • BrickIMUV2->FUNCTION_DISABLE_STATUS_LED = 239
  • BrickIMUV2->FUNCTION_RESET = 243
BrickIMUV2->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.

BrickIMUV2->set_spitfp_baudrate_config($enable_dynamic_baudrate, $minimum_dynamic_baudrate)
Parameters:
  • $enable_dynamic_baudrate -- bool
  • $minimum_dynamic_baudrate -- int
Return type:

undef

The SPITF protocol can be used with a dynamic baudrate. If the dynamic baudrate is enabled, the Brick will try to adapt the baudrate for the communication between Bricks and Bricklets according to the amount of data that is transferred.

The baudrate will be increased exponentially if lots of data is send/received and decreased linearly if little data is send/received.

This lowers the baudrate in applications where little data is transferred (e.g. a weather station) and increases the robustness. If there is lots of data to transfer (e.g. Thermal Imaging Bricklet) it automatically increases the baudrate as needed.

In cases where some data has to transferred as fast as possible every few seconds (e.g. RS485 Bricklet with a high baudrate but small payload) you may want to turn the dynamic baudrate off to get the highest possible performance.

The maximum value of the baudrate can be set per port with the function set_spitfp_baudrate(). If the dynamic baudrate is disabled, the baudrate as set by set_spitfp_baudrate() will be used statically.

The minimum dynamic baudrate has a value range of 400000 to 2000000 baud.

By default dynamic baudrate is enabled and the minimum dynamic baudrate is 400000.

New in version 2.0.10 (Firmware).

BrickIMUV2->get_spitfp_baudrate_config()
Return type:[bool, int]

Returns the baudrate config, see set_spitfp_baudrate_config().

New in version 2.0.10 (Firmware).

The returned array contains the elements enable_dynamic_baudrate and minimum_dynamic_baudrate.

BrickIMUV2->get_send_timeout_count($communication_method)
Parameters:$communication_method -- int
Return type:int

Returns the timeout count for the different communication methods.

The methods 0-2 are available for all Bricks, 3-7 only for Master Bricks.

This function is mostly used for debugging during development, in normal operation the counters should nearly always stay at 0.

The following constants are available for this function:

  • BrickIMUV2->COMMUNICATION_METHOD_NONE = 0
  • BrickIMUV2->COMMUNICATION_METHOD_USB = 1
  • BrickIMUV2->COMMUNICATION_METHOD_SPI_STACK = 2
  • BrickIMUV2->COMMUNICATION_METHOD_CHIBI = 3
  • BrickIMUV2->COMMUNICATION_METHOD_RS485 = 4
  • BrickIMUV2->COMMUNICATION_METHOD_WIFI = 5
  • BrickIMUV2->COMMUNICATION_METHOD_ETHERNET = 6
  • BrickIMUV2->COMMUNICATION_METHOD_WIFI_V2 = 7

New in version 2.0.7 (Firmware).

BrickIMUV2->set_spitfp_baudrate($bricklet_port, $baudrate)
Parameters:
  • $bricklet_port -- char
  • $baudrate -- int
Return type:

undef

Sets the baudrate for a specific Bricklet port ('a' - 'd'). The baudrate can be in the range 400000 to 2000000.

If you want to increase the throughput of Bricklets you can increase the baudrate. If you get a high error count because of high interference (see get_spitfp_error_count()) you can decrease the baudrate.

If the dynamic baudrate feature is enabled, the baudrate set by this function corresponds to the maximum baudrate (see set_spitfp_baudrate_config()).

Regulatory testing is done with the default baudrate. If CE compatibility or similar is necessary in you applications we recommend to not change the baudrate.

The default baudrate for all ports is 1400000.

New in version 2.0.5 (Firmware).

BrickIMUV2->get_spitfp_baudrate($bricklet_port)
Parameters:$bricklet_port -- char
Return type:int

Returns the baudrate for a given Bricklet port, see set_spitfp_baudrate().

New in version 2.0.5 (Firmware).

BrickIMUV2->get_spitfp_error_count($bricklet_port)
Parameters:$bricklet_port -- char
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 Brick side. All Bricklets have a similar function that returns the errors on the Bricklet side.

New in version 2.0.5 (Firmware).

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

BrickIMUV2->enable_status_led()
Return type:undef

Enables the status LED.

The status LED is the blue LED next to the USB connector. If enabled is is on and it flickers if data is transfered. If disabled it is always off.

The default state is enabled.

BrickIMUV2->disable_status_led()
Return type:undef

Disables the status LED.

The status LED is the blue LED next to the USB connector. If enabled is is on and it flickers if data is transfered. If disabled it is always off.

The default state is enabled.

BrickIMUV2->is_status_led_enabled()
Return type:bool

Returns true if the status LED is enabled, false otherwise.

BrickIMUV2->get_protocol1_bricklet_name($port)
Parameters:$port -- char
Return type:[int, [int, int, int], string]

Returns the firmware and protocol version and the name of the Bricklet for a given port.

This functions sole purpose is to allow automatic flashing of v1.x.y Bricklet plugins.

The returned array contains the elements protocol_version, firmware_version and name.

BrickIMUV2->get_chip_temperature()
Return type:int

Returns the temperature in °C/10 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 an accuracy of +-15%. Practically it is only useful as an indicator for temperature changes.

BrickIMUV2->reset()
Return type:undef

Calling this function will reset the Brick. Calling this function on a Brick inside of a stack will reset the whole stack.

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

BrickIMUV2->get_identity()
Return type:[string, string, char, [int, int, int], [int, int, int], int]

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

The position can be '0'-'8' (stack position).

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

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

Callback Configuration Functions

BrickIMUV2->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.

BrickIMUV2->set_acceleration_period($period)
Parameters:$period -- int
Return type:undef

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

The default value is 0.

BrickIMUV2->get_acceleration_period()
Return type:int

Returns the period as set by set_acceleration_period().

BrickIMUV2->set_magnetic_field_period($period)
Parameters:$period -- int
Return type:undef

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

BrickIMUV2->get_magnetic_field_period()
Return type:int

Returns the period as set by set_magnetic_field_period().

BrickIMUV2->set_angular_velocity_period($period)
Parameters:$period -- int
Return type:undef

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

BrickIMUV2->get_angular_velocity_period()
Return type:int

Returns the period as set by set_angular_velocity_period().

BrickIMUV2->set_temperature_period($period)
Parameters:$period -- int
Return type:undef

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

BrickIMUV2->get_temperature_period()
Return type:int

Returns the period as set by set_temperature_period().

BrickIMUV2->set_orientation_period($period)
Parameters:$period -- int
Return type:undef

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

BrickIMUV2->get_orientation_period()
Return type:int

Returns the period as set by set_orientation_period().

BrickIMUV2->set_linear_acceleration_period($period)
Parameters:$period -- int
Return type:undef

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

BrickIMUV2->get_linear_acceleration_period()
Return type:int

Returns the period as set by set_linear_acceleration_period().

BrickIMUV2->set_gravity_vector_period($period)
Parameters:$period -- int
Return type:undef

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

BrickIMUV2->get_gravity_vector_period()
Return type:int

Returns the period as set by set_gravity_vector_period().

BrickIMUV2->set_quaternion_period($period)
Parameters:$period -- int
Return type:undef

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

BrickIMUV2->get_quaternion_period()
Return type:int

Returns the period as set by set_quaternion_period().

BrickIMUV2->set_all_data_period($period)
Parameters:$period -- int
Return type:undef

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

BrickIMUV2->get_all_data_period()
Return type:int

Returns the period as set by set_all_data_period().

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]";
}

$imu_v2->register_callback(BrickIMUV2->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.

BrickIMUV2->CALLBACK_ACCELERATION
Parameters:
  • $x -- int
  • $y -- int
  • $z -- int

This callback is triggered periodically with the period that is set by set_acceleration_period(). The parameters are the acceleration for the x, y and z axis.

BrickIMUV2->CALLBACK_MAGNETIC_FIELD
Parameters:
  • $x -- int
  • $y -- int
  • $z -- int

This callback is triggered periodically with the period that is set by set_magnetic_field_period(). The parameters are the magnetic field for the x, y and z axis.

BrickIMUV2->CALLBACK_ANGULAR_VELOCITY
Parameters:
  • $x -- int
  • $y -- int
  • $z -- int

This callback is triggered periodically with the period that is set by set_angular_velocity_period(). The parameters are the angular velocity for the x, y and z axis.

BrickIMUV2->CALLBACK_TEMPERATURE
Parameters:$temperature -- int

This callback is triggered periodically with the period that is set by set_temperature_period(). The parameter is the temperature.

BrickIMUV2->CALLBACK_LINEAR_ACCELERATION
Parameters:
  • $x -- int
  • $y -- int
  • $z -- int

This callback is triggered periodically with the period that is set by set_linear_acceleration_period(). The parameters are the linear acceleration for the x, y and z axis.

BrickIMUV2->CALLBACK_GRAVITY_VECTOR
Parameters:
  • $x -- int
  • $y -- int
  • $z -- int

This callback is triggered periodically with the period that is set by set_gravity_vector_period(). The parameters gravity vector for the x, y and z axis.

BrickIMUV2->CALLBACK_ORIENTATION
Parameters:
  • $heading -- int
  • $roll -- int
  • $pitch -- int

This callback is triggered periodically with the period that is set by set_orientation_period(). The parameters are the orientation (heading (yaw), roll, pitch) of the IMU Brick in Euler angles. See get_orientation() for details.

BrickIMUV2->CALLBACK_QUATERNION
Parameters:
  • $w -- int
  • $x -- int
  • $y -- int
  • $z -- int

This callback is triggered periodically with the period that is set by set_quaternion_period(). The parameters are the orientation (x, y, z, w) of the IMU Brick in quaternions. See get_quaternion() for details.

BrickIMUV2->CALLBACK_ALL_DATA
Parameters:
  • @acceleration -- [int, int, int]
  • @magnetic_field -- [int, int, int]
  • @angular_velocity -- [int, int, int]
  • @euler_angle -- [int, int, int]
  • @quaternion -- [int, int, int, int]
  • @linear_acceleration -- [int, int, int]
  • @gravity_vector -- [int, int, int]
  • $temperature -- int
  • $calibration_status -- int

This callback is triggered periodically with the period that is set by set_all_data_period(). The parameters are as for get_all_data().

Constants

BrickIMUV2->DEVICE_IDENTIFIER

This constant is used to identify a IMU Brick 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.

BrickIMUV2->DEVICE_DISPLAY_NAME

This constant represents the human readable name of a IMU Brick 2.0.