MQTT - IMU Brick 2.0

This is the description of the MQTT 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 MQTT API bindings is part of their general description.

Examples

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

Simple

Download (example-simple.txt)

1
2
3
4
5
6
# Change XXYYZZ to the UID of your IMU Brick 2.0

setup:
    # Get current quaternion
    subscribe to tinkerforge/response/imu_v2_brick/XXYYZZ/get_quaternion
    publish '' to tinkerforge/request/imu_v2_brick/XXYYZZ/get_quaternion

All Data

Download (example-all-data.txt)

1
2
3
4
5
6
7
8
9
# Change XXYYZZ to the UID of your IMU Brick 2.0

setup:
    # Handle incoming all data callbacks
    subscribe to tinkerforge/callback/imu_v2_brick/XXYYZZ/all_data
    publish '{"register": true}' to tinkerforge/register/imu_v2_brick/XXYYZZ/all_data # Register all_data callback

    # Set period for all data callback to 0.1s (100ms)
    publish '{"period": 100}' to tinkerforge/request/imu_v2_brick/XXYYZZ/set_all_data_period

Callback

Download (example-callback.txt)

1
2
3
4
5
6
7
8
9
# Change XXYYZZ to the UID of your IMU Brick 2.0

setup:
    # Handle incoming quaternion callbacks
    subscribe to tinkerforge/callback/imu_v2_brick/XXYYZZ/quaternion
    publish '{"register": true}' to tinkerforge/register/imu_v2_brick/XXYYZZ/quaternion # Register quaternion callback

    # Set period for quaternion callback to 0.1s (100ms)
    publish '{"period": 100}' to tinkerforge/request/imu_v2_brick/XXYYZZ/set_quaternion_period

API

All published payloads to and from the MQTT bindings are in JSON format.

If an error occures, the bindings publish a JSON object containing the error message as member _ERROR. It is published on the corresponding response topic: .../response/... for .../request/... and .../callback/... for .../register/....

Basic Functions

request/imu_v2_brick/<UID>/get_orientation
Request:
  • empty payload
Response:
  • heading – Type: int, Unit: 1/16 °, Range: [0 to 5760]
  • roll – Type: int, Unit: 1/16 °, Range: [-1440 to 1440]
  • pitch – Type: int, Unit: 1/16 °, Range: [-2880 to 2880]

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

If you want to get the orientation periodically, it is recommended to use the register/imu_v2_brick/<UID>/orientation callback and set the period with request/imu_v2_brick/<UID>/set_orientation_period.

request/imu_v2_brick/<UID>/get_linear_acceleration
Request:
  • empty payload
Response:
  • x – Type: int, Unit: 1 cm/s², Range: ?
  • y – Type: int, Unit: 1 cm/s², Range: ?
  • z – Type: int, Unit: 1 cm/s², Range: ?

Returns the linear acceleration of the IMU Brick for the x, y and z axis. The acceleration is in the range configured with request/imu_v2_brick/<UID>/set_sensor_configuration.

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 request/imu_v2_brick/<UID>/get_gravity_vector.

If you want to get the linear acceleration periodically, it is recommended to use the register/imu_v2_brick/<UID>/linear_acceleration callback and set the period with request/imu_v2_brick/<UID>/set_linear_acceleration_period.

request/imu_v2_brick/<UID>/get_gravity_vector
Request:
  • empty payload
Response:
  • x – Type: int, Unit: 1 cm/s², Range: [-981 to 981]
  • y – Type: int, Unit: 1 cm/s², Range: [-981 to 981]
  • z – Type: int, Unit: 1 cm/s², Range: [-981 to 981]

Returns the current gravity vector of the IMU Brick for the x, y and z axis.

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 request/imu_v2_brick/<UID>/get_linear_acceleration.

If you want to get the gravity vector periodically, it is recommended to use the register/imu_v2_brick/<UID>/gravity_vector callback and set the period with request/imu_v2_brick/<UID>/set_gravity_vector_period.

request/imu_v2_brick/<UID>/get_quaternion
Request:
  • empty payload
Response:
  • w – Type: int, Unit: 1/16383, Range: [-214 + 1 to 214 - 1]
  • x – Type: int, Unit: 1/16383, Range: [-214 + 1 to 214 - 1]
  • y – Type: int, Unit: 1/16383, Range: [-214 + 1 to 214 - 1]
  • z – Type: int, Unit: 1/16383, Range: [-214 + 1 to 214 - 1]

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

You have to divide the return 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 register/imu_v2_brick/<UID>/quaternion callback and set the period with request/imu_v2_brick/<UID>/set_quaternion_period.

request/imu_v2_brick/<UID>/get_all_data
Request:
  • empty payload
Response:
  • acceleration – Type: [int, ...], Length: 3
    • 0: x – Type: int, Unit: 1 cm/s², Range: ?
    • 1: y – Type: int, Unit: 1 cm/s², Range: ?
    • 2: z – Type: int, Unit: 1 cm/s², Range: ?
  • magnetic_field – Type: [int, ...], Length: 3
    • 0: x – Type: int, Unit: 1/16 µT, Range: [-20800 to 20800]
    • 1: y – Type: int, Unit: 1/16 µT, Range: [-20800 to 20800]
    • 2: z – Type: int, Unit: 1/16 µT, Range: [-40000 to 40000]
  • angular_velocity – Type: [int, ...], Length: 3
    • 0: x – Type: int, Unit: 1/16 °/s, Range: ?
    • 1: y – Type: int, Unit: 1/16 °/s, Range: ?
    • 2: z – Type: int, Unit: 1/16 °/s, Range: ?
  • euler_angle – Type: [int, ...], Length: 3
    • 0: heading – Type: int, Unit: 1/16 °, Range: [0 to 5760]
    • 1: roll – Type: int, Unit: 1/16 °, Range: [-1440 to 1440]
    • 2: pitch – Type: int, Unit: 1/16 °, Range: [-2880 to 2880]
  • quaternion – Type: [int, ...], Length: 4
    • 0: w – Type: int, Unit: 1/16383, Range: [-214 + 1 to 214 - 1]
    • 1: x – Type: int, Unit: 1/16383, Range: [-214 + 1 to 214 - 1]
    • 2: y – Type: int, Unit: 1/16383, Range: [-214 + 1 to 214 - 1]
    • 3: z – Type: int, Unit: 1/16383, Range: [-214 + 1 to 214 - 1]
  • linear_acceleration – Type: [int, ...], Length: 3
    • 0: x – Type: int, Unit: 1 cm/s², Range: ?
    • 1: y – Type: int, Unit: 1 cm/s², Range: ?
    • 2: z – Type: int, Unit: 1 cm/s², Range: ?
  • gravity_vector – Type: [int, ...], Length: 3
    • 0: x – Type: int, Unit: 1 cm/s², Range: [-981 to 981]
    • 1: y – Type: int, Unit: 1 cm/s², Range: [-981 to 981]
    • 2: z – Type: int, Unit: 1 cm/s², Range: [-981 to 981]
  • temperature – Type: int, Unit: 1 °C, Range: [-128 to 127]
  • calibration_status – Type: int, Range: [0 to 255]

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 register/imu_v2_brick/<UID>/all_data callback and set the period with request/imu_v2_brick/<UID>/set_all_data_period.

request/imu_v2_brick/<UID>/leds_on
Request:
  • empty payload
Response:
  • no response

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

request/imu_v2_brick/<UID>/leds_off
Request:
  • empty payload
Response:
  • no response

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

request/imu_v2_brick/<UID>/are_leds_on
Request:
  • empty payload
Response:
  • leds – Type: bool, Default: true

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

Advanced Functions

request/imu_v2_brick/<UID>/get_acceleration
Request:
  • empty payload
Response:
  • x – Type: int, Unit: 1 cm/s², Range: ?
  • y – Type: int, Unit: 1 cm/s², Range: ?
  • z – Type: int, Unit: 1 cm/s², Range: ?

Returns the calibrated acceleration from the accelerometer for the x, y and z axis. The acceleration is in the range configured with request/imu_v2_brick/<UID>/set_sensor_configuration.

If you want to get the acceleration periodically, it is recommended to use the register/imu_v2_brick/<UID>/acceleration callback and set the period with request/imu_v2_brick/<UID>/set_acceleration_period.

request/imu_v2_brick/<UID>/get_magnetic_field
Request:
  • empty payload
Response:
  • x – Type: int, Unit: 1/16 µT, Range: [-20800 to 20800]
  • y – Type: int, Unit: 1/16 µT, Range: [-20800 to 20800]
  • z – Type: int, Unit: 1/16 µT, Range: [-40000 to 40000]

Returns the calibrated magnetic field from the magnetometer for the x, y and z axis.

If you want to get the magnetic field periodically, it is recommended to use the register/imu_v2_brick/<UID>/magnetic_field callback and set the period with request/imu_v2_brick/<UID>/set_magnetic_field_period.

request/imu_v2_brick/<UID>/get_angular_velocity
Request:
  • empty payload
Response:
  • x – Type: int, Unit: 1/16 °/s, Range: ?
  • y – Type: int, Unit: 1/16 °/s, Range: ?
  • z – Type: int, Unit: 1/16 °/s, Range: ?

Returns the calibrated angular velocity from the gyroscope for the x, y and z axis. The angular velocity is in the range configured with request/imu_v2_brick/<UID>/set_sensor_configuration.

If you want to get the angular velocity periodically, it is recommended to use the register/imu_v2_brick/<UID>/angular_velocity acallback nd set the period with request/imu_v2_brick/<UID>/set_angular_velocity_period.

request/imu_v2_brick/<UID>/get_temperature
Request:
  • empty payload
Response:
  • temperature – Type: int, Unit: 1 °C, Range: [-128 to 127]

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

request/imu_v2_brick/<UID>/save_calibration
Request:
  • empty payload
Response:
  • calibration_done – 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.

request/imu_v2_brick/<UID>/set_sensor_configuration
Request:
  • magnetometer_rate – Type: int, Range: See symbols, Default: 5
  • gyroscope_range – Type: int, Range: See symbols, Default: 0
  • gyroscope_bandwidth – Type: int, Range: See symbols, Default: 7
  • accelerometer_range – Type: int, Range: See symbols, Default: 1
  • accelerometer_bandwidth – Type: int, Range: See symbols, Default: 3
Response:
  • no response

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 following symbols are available for this function:

For magnetometer_rate:

  • "2hz" = 0
  • "6hz" = 1
  • "8hz" = 2
  • "10hz" = 3
  • "15hz" = 4
  • "20hz" = 5
  • "25hz" = 6
  • "30hz" = 7

For gyroscope_range:

  • "2000dps" = 0
  • "1000dps" = 1
  • "500dps" = 2
  • "250dps" = 3
  • "125dps" = 4

For gyroscope_bandwidth:

  • "523hz" = 0
  • "230hz" = 1
  • "116hz" = 2
  • "47hz" = 3
  • "23hz" = 4
  • "12hz" = 5
  • "64hz" = 6
  • "32hz" = 7

For accelerometer_range:

  • "2g" = 0
  • "4g" = 1
  • "8g" = 2
  • "16g" = 3

For accelerometer_bandwidth:

  • "7_81hz" = 0
  • "15_63hz" = 1
  • "31_25hz" = 2
  • "62_5hz" = 3
  • "125hz" = 4
  • "250hz" = 5
  • "500hz" = 6
  • "1000hz" = 7

New in version 2.0.5 (Firmware).

request/imu_v2_brick/<UID>/get_sensor_configuration
Request:
  • empty payload
Response:
  • magnetometer_rate – Type: int, Range: See symbols, Default: 5
  • gyroscope_range – Type: int, Range: See symbols, Default: 0
  • gyroscope_bandwidth – Type: int, Range: See symbols, Default: 7
  • accelerometer_range – Type: int, Range: See symbols, Default: 1
  • accelerometer_bandwidth – Type: int, Range: See symbols, Default: 3

Returns the sensor configuration as set by request/imu_v2_brick/<UID>/set_sensor_configuration.

The following symbols are available for this function:

For magnetometer_rate:

  • "2hz" = 0
  • "6hz" = 1
  • "8hz" = 2
  • "10hz" = 3
  • "15hz" = 4
  • "20hz" = 5
  • "25hz" = 6
  • "30hz" = 7

For gyroscope_range:

  • "2000dps" = 0
  • "1000dps" = 1
  • "500dps" = 2
  • "250dps" = 3
  • "125dps" = 4

For gyroscope_bandwidth:

  • "523hz" = 0
  • "230hz" = 1
  • "116hz" = 2
  • "47hz" = 3
  • "23hz" = 4
  • "12hz" = 5
  • "64hz" = 6
  • "32hz" = 7

For accelerometer_range:

  • "2g" = 0
  • "4g" = 1
  • "8g" = 2
  • "16g" = 3

For accelerometer_bandwidth:

  • "7_81hz" = 0
  • "15_63hz" = 1
  • "31_25hz" = 2
  • "62_5hz" = 3
  • "125hz" = 4
  • "250hz" = 5
  • "500hz" = 6
  • "1000hz" = 7

New in version 2.0.5 (Firmware).

request/imu_v2_brick/<UID>/set_sensor_fusion_mode
Request:
  • mode – Type: int, Range: See symbols, Default: 1
Response:
  • no response

If the fusion mode is turned off, the functions request/imu_v2_brick/<UID>/get_acceleration, request/imu_v2_brick/<UID>/get_magnetic_field and request/imu_v2_brick/<UID>/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.

The following symbols are available for this function:

For mode:

  • "off" = 0
  • "on" = 1
  • "on_without_magnetometer" = 2
  • "on_without_fast_magnetometer_calibration" = 3

New in version 2.0.5 (Firmware).

request/imu_v2_brick/<UID>/get_sensor_fusion_mode
Request:
  • empty payload
Response:
  • mode – Type: int, Range: See symbols, Default: 1

Returns the sensor fusion mode as set by request/imu_v2_brick/<UID>/set_sensor_fusion_mode.

The following symbols are available for this function:

For mode:

  • "off" = 0
  • "on" = 1
  • "on_without_magnetometer" = 2
  • "on_without_fast_magnetometer_calibration" = 3

New in version 2.0.5 (Firmware).

request/imu_v2_brick/<UID>/set_spitfp_baudrate_config
Request:
  • enable_dynamic_baudrate – Type: bool, Default: true
  • minimum_dynamic_baudrate – Type: int, Unit: 1 Bd, Range: [400000 to 2000000], Default: 400000
Response:
  • no response

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 sent/received and decreased linearly if little data is sent/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 request/imu_v2_brick/<UID>/set_spitfp_baudrate. If the dynamic baudrate is disabled, the baudrate as set by request/imu_v2_brick/<UID>/set_spitfp_baudrate will be used statically.

New in version 2.0.10 (Firmware).

request/imu_v2_brick/<UID>/get_spitfp_baudrate_config
Request:
  • empty payload
Response:
  • enable_dynamic_baudrate – Type: bool, Default: true
  • minimum_dynamic_baudrate – Type: int, Unit: 1 Bd, Range: [400000 to 2000000], Default: 400000

Returns the baudrate config, see request/imu_v2_brick/<UID>/set_spitfp_baudrate_config.

New in version 2.0.10 (Firmware).

request/imu_v2_brick/<UID>/get_send_timeout_count
Request:
  • communication_method – Type: int, Range: See symbols
Response:
  • timeout_count – Type: int, Range: [0 to 232 - 1]

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 symbols are available for this function:

For communication_method:

  • "none" = 0
  • "usb" = 1
  • "spi_stack" = 2
  • "chibi" = 3
  • "rs485" = 4
  • "wifi" = 5
  • "ethernet" = 6
  • "wifi_v2" = 7

New in version 2.0.7 (Firmware).

request/imu_v2_brick/<UID>/set_spitfp_baudrate
Request:
  • bricklet_port – Type: char, Range: ["a" to "b"]
  • baudrate – Type: int, Unit: 1 Bd, Range: [400000 to 2000000], Default: 1400000
Response:
  • no response

Sets the baudrate for a specific Bricklet port.

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 request/imu_v2_brick/<UID>/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 request/imu_v2_brick/<UID>/set_spitfp_baudrate_config).

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

New in version 2.0.5 (Firmware).

request/imu_v2_brick/<UID>/get_spitfp_baudrate
Request:
  • bricklet_port – Type: char, Range: ["a" to "b"]
Response:
  • baudrate – Type: int, Unit: 1 Bd, Range: [400000 to 2000000], Default: 1400000

Returns the baudrate for a given Bricklet port, see request/imu_v2_brick/<UID>/set_spitfp_baudrate.

New in version 2.0.5 (Firmware).

request/imu_v2_brick/<UID>/get_spitfp_error_count
Request:
  • bricklet_port – Type: char, Range: ["a" to "b"]
Response:
  • error_count_ack_checksum – Type: int, Range: [0 to 232 - 1]
  • error_count_message_checksum – Type: int, Range: [0 to 232 - 1]
  • error_count_frame – Type: int, Range: [0 to 232 - 1]
  • 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 Brick side. All Bricklets have a similar function that returns the errors on the Bricklet side.

New in version 2.0.5 (Firmware).

request/imu_v2_brick/<UID>/enable_status_led
Request:
  • empty payload
Response:
  • no response

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.

request/imu_v2_brick/<UID>/disable_status_led
Request:
  • empty payload
Response:
  • no response

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.

request/imu_v2_brick/<UID>/is_status_led_enabled
Request:
  • empty payload
Response:
  • enabled – Type: bool, Default: true

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

request/imu_v2_brick/<UID>/get_chip_temperature
Request:
  • empty payload
Response:
  • temperature – Type: int, Unit: 1/10 °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 an accuracy of ±15%. Practically it is only useful as an indicator for temperature changes.

request/imu_v2_brick/<UID>/reset
Request:
  • empty payload
Response:
  • no response

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!

request/imu_v2_brick/<UID>/get_identity
Request:
  • empty payload
Response:
  • uid – Type: string, Length: up to 8
  • connected_uid – Type: string, Length: up to 8
  • position – Type: char, Range: ["0" to "8"]
  • 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]
  • 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]
  • device_identifier – Type: int, Range: [0 to 216 - 1]
  • _display_name – Type: string

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 is the position in the stack from '0' (bottom) to '8' (top).

The device identifier numbers can be found here. If symbolic output is not disabled, the device identifier is mapped to the corresponding name in the format used in topics.

The display name contains the IMU 2.0's name in a human readable form.

Callback Configuration Functions

request/imu_v2_brick/<UID>/set_acceleration_period
Request:
  • period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
Response:
  • no response

Sets the period with which the register/imu_v2_brick/<UID>/acceleration callback is triggered periodically. A value of 0 turns the callback off.

request/imu_v2_brick/<UID>/get_acceleration_period
Request:
  • empty payload
Response:
  • period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0

Returns the period as set by request/imu_v2_brick/<UID>/set_acceleration_period.

request/imu_v2_brick/<UID>/set_magnetic_field_period
Request:
  • period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
Response:
  • no response

Sets the period with which the register/imu_v2_brick/<UID>/magnetic_field callback is triggered periodically. A value of 0 turns the callback off.

request/imu_v2_brick/<UID>/get_magnetic_field_period
Request:
  • empty payload
Response:
  • period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0

Returns the period as set by request/imu_v2_brick/<UID>/set_magnetic_field_period.

request/imu_v2_brick/<UID>/set_angular_velocity_period
Request:
  • period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
Response:
  • no response

Sets the period with which the register/imu_v2_brick/<UID>/angular_velocity callback is triggered periodically. A value of 0 turns the callback off.

request/imu_v2_brick/<UID>/get_angular_velocity_period
Request:
  • empty payload
Response:
  • period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0

Returns the period as set by request/imu_v2_brick/<UID>/set_angular_velocity_period.

request/imu_v2_brick/<UID>/set_temperature_period
Request:
  • period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
Response:
  • no response

Sets the period with which the register/imu_v2_brick/<UID>/temperature callback is triggered periodically. A value of 0 turns the callback off.

request/imu_v2_brick/<UID>/get_temperature_period
Request:
  • empty payload
Response:
  • period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0

Returns the period as set by request/imu_v2_brick/<UID>/set_temperature_period.

request/imu_v2_brick/<UID>/set_orientation_period
Request:
  • period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
Response:
  • no response

Sets the period with which the register/imu_v2_brick/<UID>/orientation callback is triggered periodically. A value of 0 turns the callback off.

request/imu_v2_brick/<UID>/get_orientation_period
Request:
  • empty payload
Response:
  • period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0

Returns the period as set by request/imu_v2_brick/<UID>/set_orientation_period.

request/imu_v2_brick/<UID>/set_linear_acceleration_period
Request:
  • period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
Response:
  • no response

Sets the period with which the register/imu_v2_brick/<UID>/linear_acceleration callback is triggered periodically. A value of 0 turns the callback off.

request/imu_v2_brick/<UID>/get_linear_acceleration_period
Request:
  • empty payload
Response:
  • period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0

Returns the period as set by request/imu_v2_brick/<UID>/set_linear_acceleration_period.

request/imu_v2_brick/<UID>/set_gravity_vector_period
Request:
  • period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
Response:
  • no response

Sets the period with which the register/imu_v2_brick/<UID>/gravity_vector callback is triggered periodically. A value of 0 turns the callback off.

request/imu_v2_brick/<UID>/get_gravity_vector_period
Request:
  • empty payload
Response:
  • period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0

Returns the period as set by request/imu_v2_brick/<UID>/set_gravity_vector_period.

request/imu_v2_brick/<UID>/set_quaternion_period
Request:
  • period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
Response:
  • no response

Sets the period with which the register/imu_v2_brick/<UID>/quaternion callback is triggered periodically. A value of 0 turns the callback off.

request/imu_v2_brick/<UID>/get_quaternion_period
Request:
  • empty payload
Response:
  • period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0

Returns the period as set by request/imu_v2_brick/<UID>/set_quaternion_period.

request/imu_v2_brick/<UID>/set_all_data_period
Request:
  • period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0
Response:
  • no response

Sets the period with which the register/imu_v2_brick/<UID>/all_data callback is triggered periodically. A value of 0 turns the callback off.

request/imu_v2_brick/<UID>/get_all_data_period
Request:
  • empty payload
Response:
  • period – Type: int, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0

Returns the period as set by request/imu_v2_brick/<UID>/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 corresponding .../register/... topic and an optional suffix. This suffix can be used to deregister the callback later.

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.

register/imu_v2_brick/<UID>/acceleration
Register Request:
  • register – Type: bool
Callback Response:
  • x – Type: int, Unit: 1 cm/s², Range: ?
  • y – Type: int, Unit: 1 cm/s², Range: ?
  • z – Type: int, Unit: 1 cm/s², Range: ?

A callback can be registered for this event by publishing to the .../register/imu_v2_brick/<UID>/acceleration[/<SUFFIX>] topic with the payload "true". An added callback can be removed by publishing to the same topic with the payload "false". To support multiple (de)registrations, e.g. for message filtering, an optional suffix can be used.

If the callback is triggered, a message with it's payload is published under the corresponding .../callback/imu_v2_brick/<UID>/acceleration[/<SUFFIX>] topic for each registered suffix.

This callback is triggered periodically with the period that is set by request/imu_v2_brick/<UID>/set_acceleration_period. The callback payload members are the acceleration for the x, y and z axis.

register/imu_v2_brick/<UID>/magnetic_field
Register Request:
  • register – Type: bool
Callback Response:
  • x – Type: int, Unit: 1/16 µT, Range: [-20800 to 20800]
  • y – Type: int, Unit: 1/16 µT, Range: [-20800 to 20800]
  • z – Type: int, Unit: 1/16 µT, Range: [-40000 to 40000]

A callback can be registered for this event by publishing to the .../register/imu_v2_brick/<UID>/magnetic_field[/<SUFFIX>] topic with the payload "true". An added callback can be removed by publishing to the same topic with the payload "false". To support multiple (de)registrations, e.g. for message filtering, an optional suffix can be used.

If the callback is triggered, a message with it's payload is published under the corresponding .../callback/imu_v2_brick/<UID>/magnetic_field[/<SUFFIX>] topic for each registered suffix.

This callback is triggered periodically with the period that is set by request/imu_v2_brick/<UID>/set_magnetic_field_period. The callback payload members are the magnetic field for the x, y and z axis.

register/imu_v2_brick/<UID>/angular_velocity
Register Request:
  • register – Type: bool
Callback Response:
  • x – Type: int, Unit: 1/16 °/s, Range: ?
  • y – Type: int, Unit: 1/16 °/s, Range: ?
  • z – Type: int, Unit: 1/16 °/s, Range: ?

A callback can be registered for this event by publishing to the .../register/imu_v2_brick/<UID>/angular_velocity[/<SUFFIX>] topic with the payload "true". An added callback can be removed by publishing to the same topic with the payload "false". To support multiple (de)registrations, e.g. for message filtering, an optional suffix can be used.

If the callback is triggered, a message with it's payload is published under the corresponding .../callback/imu_v2_brick/<UID>/angular_velocity[/<SUFFIX>] topic for each registered suffix.

This callback is triggered periodically with the period that is set by request/imu_v2_brick/<UID>/set_angular_velocity_period. The callback payload members are the angular velocity for the x, y and z axis.

register/imu_v2_brick/<UID>/temperature
Register Request:
  • register – Type: bool
Callback Response:
  • temperature – Type: int, Unit: 1 °C, Range: [-128 to 127]

A callback can be registered for this event by publishing to the .../register/imu_v2_brick/<UID>/temperature[/<SUFFIX>] topic with the payload "true". An added callback can be removed by publishing to the same topic with the payload "false". To support multiple (de)registrations, e.g. for message filtering, an optional suffix can be used.

If the callback is triggered, a message with it's payload is published under the corresponding .../callback/imu_v2_brick/<UID>/temperature[/<SUFFIX>] topic for each registered suffix.

This callback is triggered periodically with the period that is set by request/imu_v2_brick/<UID>/set_temperature_period. The callback payload is the temperature.

register/imu_v2_brick/<UID>/linear_acceleration
Register Request:
  • register – Type: bool
Callback Response:
  • x – Type: int, Unit: 1 cm/s², Range: ?
  • y – Type: int, Unit: 1 cm/s², Range: ?
  • z – Type: int, Unit: 1 cm/s², Range: ?

A callback can be registered for this event by publishing to the .../register/imu_v2_brick/<UID>/linear_acceleration[/<SUFFIX>] topic with the payload "true". An added callback can be removed by publishing to the same topic with the payload "false". To support multiple (de)registrations, e.g. for message filtering, an optional suffix can be used.

If the callback is triggered, a message with it's payload is published under the corresponding .../callback/imu_v2_brick/<UID>/linear_acceleration[/<SUFFIX>] topic for each registered suffix.

This callback is triggered periodically with the period that is set by request/imu_v2_brick/<UID>/set_linear_acceleration_period. The callback payload members are the linear acceleration for the x, y and z axis.

register/imu_v2_brick/<UID>/gravity_vector
Register Request:
  • register – Type: bool
Callback Response:
  • x – Type: int, Unit: 1 cm/s², Range: [-981 to 981]
  • y – Type: int, Unit: 1 cm/s², Range: [-981 to 981]
  • z – Type: int, Unit: 1 cm/s², Range: [-981 to 981]

A callback can be registered for this event by publishing to the .../register/imu_v2_brick/<UID>/gravity_vector[/<SUFFIX>] topic with the payload "true". An added callback can be removed by publishing to the same topic with the payload "false". To support multiple (de)registrations, e.g. for message filtering, an optional suffix can be used.

If the callback is triggered, a message with it's payload is published under the corresponding .../callback/imu_v2_brick/<UID>/gravity_vector[/<SUFFIX>] topic for each registered suffix.

This callback is triggered periodically with the period that is set by request/imu_v2_brick/<UID>/set_gravity_vector_period. The callback payload members gravity vector for the x, y and z axis.

register/imu_v2_brick/<UID>/orientation
Register Request:
  • register – Type: bool
Callback Response:
  • heading – Type: int, Unit: 1/16 °, Range: [0 to 5760]
  • roll – Type: int, Unit: 1/16 °, Range: [-1440 to 1440]
  • pitch – Type: int, Unit: 1/16 °, Range: [-2880 to 2880]

A callback can be registered for this event by publishing to the .../register/imu_v2_brick/<UID>/orientation[/<SUFFIX>] topic with the payload "true". An added callback can be removed by publishing to the same topic with the payload "false". To support multiple (de)registrations, e.g. for message filtering, an optional suffix can be used.

If the callback is triggered, a message with it's payload is published under the corresponding .../callback/imu_v2_brick/<UID>/orientation[/<SUFFIX>] topic for each registered suffix.

This callback is triggered periodically with the period that is set by request/imu_v2_brick/<UID>/set_orientation_period. The callback payload members are the orientation (heading (yaw), roll, pitch) of the IMU Brick in Euler angles. See request/imu_v2_brick/<UID>/get_orientation for details.

register/imu_v2_brick/<UID>/quaternion
Register Request:
  • register – Type: bool
Callback Response:
  • w – Type: int, Unit: 1/16383, Range: [-214 + 1 to 214 - 1]
  • x – Type: int, Unit: 1/16383, Range: [-214 + 1 to 214 - 1]
  • y – Type: int, Unit: 1/16383, Range: [-214 + 1 to 214 - 1]
  • z – Type: int, Unit: 1/16383, Range: [-214 + 1 to 214 - 1]

A callback can be registered for this event by publishing to the .../register/imu_v2_brick/<UID>/quaternion[/<SUFFIX>] topic with the payload "true". An added callback can be removed by publishing to the same topic with the payload "false". To support multiple (de)registrations, e.g. for message filtering, an optional suffix can be used.

If the callback is triggered, a message with it's payload is published under the corresponding .../callback/imu_v2_brick/<UID>/quaternion[/<SUFFIX>] topic for each registered suffix.

This callback is triggered periodically with the period that is set by request/imu_v2_brick/<UID>/set_quaternion_period. The callback payload members are the orientation (w, x, y, z) of the IMU Brick in quaternions. See request/imu_v2_brick/<UID>/get_quaternion for details.

register/imu_v2_brick/<UID>/all_data
Register Request:
  • register – Type: bool
Callback Response:
  • acceleration – Type: [int, ...], Length: 3
    • 0: x – Type: int, Unit: 1 cm/s², Range: ?
    • 1: y – Type: int, Unit: 1 cm/s², Range: ?
    • 2: z – Type: int, Unit: 1 cm/s², Range: ?
  • magnetic_field – Type: [int, ...], Length: 3
    • 0: x – Type: int, Unit: 1/16 µT, Range: [-20800 to 20800]
    • 1: y – Type: int, Unit: 1/16 µT, Range: [-20800 to 20800]
    • 2: z – Type: int, Unit: 1/16 µT, Range: [-40000 to 40000]
  • angular_velocity – Type: [int, ...], Length: 3
    • 0: x – Type: int, Unit: 1/16 °/s, Range: ?
    • 1: y – Type: int, Unit: 1/16 °/s, Range: ?
    • 2: z – Type: int, Unit: 1/16 °/s, Range: ?
  • euler_angle – Type: [int, ...], Length: 3
    • 0: heading – Type: int, Unit: 1/16 °, Range: [0 to 5760]
    • 1: roll – Type: int, Unit: 1/16 °, Range: [-1440 to 1440]
    • 2: pitch – Type: int, Unit: 1/16 °, Range: [-2880 to 2880]
  • quaternion – Type: [int, ...], Length: 4
    • 0: w – Type: int, Unit: 1/16383, Range: [-214 + 1 to 214 - 1]
    • 1: x – Type: int, Unit: 1/16383, Range: [-214 + 1 to 214 - 1]
    • 2: y – Type: int, Unit: 1/16383, Range: [-214 + 1 to 214 - 1]
    • 3: z – Type: int, Unit: 1/16383, Range: [-214 + 1 to 214 - 1]
  • linear_acceleration – Type: [int, ...], Length: 3
    • 0: x – Type: int, Unit: 1 cm/s², Range: ?
    • 1: y – Type: int, Unit: 1 cm/s², Range: ?
    • 2: z – Type: int, Unit: 1 cm/s², Range: ?
  • gravity_vector – Type: [int, ...], Length: 3
    • 0: x – Type: int, Unit: 1 cm/s², Range: ?
    • 1: y – Type: int, Unit: 1 cm/s², Range: ?
    • 2: z – Type: int, Unit: 1 cm/s², Range: ?
  • temperature – Type: int, Unit: 1 °C, Range: [-128 to 127]
  • calibration_status – Type: int, Range: [0 to 255]

A callback can be registered for this event by publishing to the .../register/imu_v2_brick/<UID>/all_data[/<SUFFIX>] topic with the payload "true". An added callback can be removed by publishing to the same topic with the payload "false". To support multiple (de)registrations, e.g. for message filtering, an optional suffix can be used.

If the callback is triggered, a message with it's payload is published under the corresponding .../callback/imu_v2_brick/<UID>/all_data[/<SUFFIX>] topic for each registered suffix.

This callback is triggered periodically with the period that is set by request/imu_v2_brick/<UID>/set_all_data_period. The callback payload members are as for request/imu_v2_brick/<UID>/get_all_data.

Internal Functions

Internal functions are used for maintenance tasks such as flashing a new firmware of changing the UID of a Bricklet. These task should be performed using Brick Viewer instead of using the internal functions directly.

request/imu_v2_brick/<UID>/get_protocol1_bricklet_name
Request:
  • port – Type: char, Range: ["a" to "b"]
Response:
  • protocol_version – Type: int, Range: [0 to 255]
  • 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]
  • name – Type: string, Length: up to 40

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.

request/imu_v2_brick/<UID>/write_bricklet_plugin
Request:
  • port – Type: char, Range: ["a" to "b"]
  • offset – Type: int, Range: [0 to 255]
  • chunk – Type: [int, ...], Length: 32, Range: [0 to 255]
Response:
  • no response

Writes 32 bytes of firmware to the bricklet attached at the given port. The bytes are written to the position offset * 32.

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

request/imu_v2_brick/<UID>/read_bricklet_plugin
Request:
  • port – Type: char, Range: ["a" to "b"]
  • offset – Type: int, Range: [0 to 255]
Response:
  • chunk – Type: [int, ...], Length: 32, Range: [0 to 255]

Reads 32 bytes of firmware from the bricklet attached at the given port. The bytes are read starting at the position offset * 32.

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