TCP/IP - IMU Brick 2.0

This is the description of the TCP/IP protocol for the IMU Brick 2.0. General information and technical specifications for the IMU Brick 2.0 are summarized in its hardware description.

API

A general description of the TCP/IP protocol structure can be found here.

Basic Functions

BrickIMUV2.get_orientation
Function ID:

5

Request:

empty payload

Response:
  • heading -- int16
  • roll -- int16
  • pitch -- int16

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.

BrickIMUV2.get_linear_acceleration
Function ID:

6

Request:

empty payload

Response:
  • x -- int16
  • y -- int16
  • z -- int16

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.

BrickIMUV2.get_gravity_vector
Function ID:

7

Request:

empty payload

Response:
  • x -- int16
  • y -- int16
  • z -- int16

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.

BrickIMUV2.get_quaternion
Function ID:

8

Request:

empty payload

Response:
  • w -- int16
  • x -- int16
  • y -- int16
  • z -- int16

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.

BrickIMUV2.get_all_data
Function ID:

9

Request:

empty payload

Response:
  • acceleration -- int16[3]
  • magnetic_field -- int16[3]
  • angular_velocity -- int16[3]
  • euler_angle -- int16[3]
  • quaternion -- int16[4]
  • linear_acceleration -- int16[3]
  • gravity_vector -- int16[3]
  • temperature -- int8
  • calibration_status -- uint8

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.

BrickIMUV2.leds_on
Function ID:10
Request:empty payload
Response:no response

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

BrickIMUV2.leds_off
Function ID:11
Request:empty payload
Response:no response

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

BrickIMUV2.are_leds_on
Function ID:

12

Request:

empty payload

Response:
  • leds -- bool

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

Advanced Functions

BrickIMUV2.get_acceleration
Function ID:

1

Request:

empty payload

Response:
  • x -- int16
  • y -- int16
  • z -- int16

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.

BrickIMUV2.get_magnetic_field
Function ID:

2

Request:

empty payload

Response:
  • x -- int16
  • y -- int16
  • z -- int16

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.

BrickIMUV2.get_angular_velocity
Function ID:

3

Request:

empty payload

Response:
  • x -- int16
  • y -- int16
  • z -- int16

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.

BrickIMUV2.get_temperature
Function ID:

4

Request:

empty payload

Response:
  • temperature -- int8

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
Function ID:

13

Request:

empty payload

Response:
  • calibration_done -- 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
Function ID:

41

Request:
  • magnetometer_rate -- uint8
  • gyroscope_range -- uint8
  • gyroscope_bandwidth -- uint8
  • accelerometer_range -- uint8
  • accelerometer_bandwidth -- uint8
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 default values are:

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

The following meanings are defined for the parameters of this function:

  • 0: 2hz, for magnetometer_rate
  • 1: 6hz, for magnetometer_rate
  • 2: 8hz, for magnetometer_rate
  • 3: 10hz, for magnetometer_rate
  • 4: 15hz, for magnetometer_rate
  • 5: 20hz, for magnetometer_rate
  • 6: 25hz, for magnetometer_rate
  • 7: 30hz, for magnetometer_rate
  • 0: 2000dps, for gyroscope_range
  • 1: 1000dps, for gyroscope_range
  • 2: 500dps, for gyroscope_range
  • 3: 250dps, for gyroscope_range
  • 4: 125dps, for gyroscope_range
  • 0: 523hz, for gyroscope_bandwidth
  • 1: 230hz, for gyroscope_bandwidth
  • 2: 116hz, for gyroscope_bandwidth
  • 3: 47hz, for gyroscope_bandwidth
  • 4: 23hz, for gyroscope_bandwidth
  • 5: 12hz, for gyroscope_bandwidth
  • 6: 64hz, for gyroscope_bandwidth
  • 7: 32hz, for gyroscope_bandwidth
  • 0: 2g, for accelerometer_range
  • 1: 4g, for accelerometer_range
  • 2: 8g, for accelerometer_range
  • 3: 16g, for accelerometer_range
  • 0: 7 81hz, for accelerometer_bandwidth
  • 1: 15 63hz, for accelerometer_bandwidth
  • 2: 31 25hz, for accelerometer_bandwidth
  • 3: 62 5hz, for accelerometer_bandwidth
  • 4: 125hz, for accelerometer_bandwidth
  • 5: 250hz, for accelerometer_bandwidth
  • 6: 500hz, for accelerometer_bandwidth
  • 7: 1000hz, for accelerometer_bandwidth

New in version 2.0.5 (Firmware).

BrickIMUV2.get_sensor_configuration
Function ID:

42

Request:

empty payload

Response:
  • magnetometer_rate -- uint8
  • gyroscope_range -- uint8
  • gyroscope_bandwidth -- uint8
  • accelerometer_range -- uint8
  • accelerometer_bandwidth -- uint8

Returns the sensor configuration as set by set_sensor_configuration.

The following meanings are defined for the parameters of this function:

  • 0: 2hz, for magnetometer_rate
  • 1: 6hz, for magnetometer_rate
  • 2: 8hz, for magnetometer_rate
  • 3: 10hz, for magnetometer_rate
  • 4: 15hz, for magnetometer_rate
  • 5: 20hz, for magnetometer_rate
  • 6: 25hz, for magnetometer_rate
  • 7: 30hz, for magnetometer_rate
  • 0: 2000dps, for gyroscope_range
  • 1: 1000dps, for gyroscope_range
  • 2: 500dps, for gyroscope_range
  • 3: 250dps, for gyroscope_range
  • 4: 125dps, for gyroscope_range
  • 0: 523hz, for gyroscope_bandwidth
  • 1: 230hz, for gyroscope_bandwidth
  • 2: 116hz, for gyroscope_bandwidth
  • 3: 47hz, for gyroscope_bandwidth
  • 4: 23hz, for gyroscope_bandwidth
  • 5: 12hz, for gyroscope_bandwidth
  • 6: 64hz, for gyroscope_bandwidth
  • 7: 32hz, for gyroscope_bandwidth
  • 0: 2g, for accelerometer_range
  • 1: 4g, for accelerometer_range
  • 2: 8g, for accelerometer_range
  • 3: 16g, for accelerometer_range
  • 0: 7 81hz, for accelerometer_bandwidth
  • 1: 15 63hz, for accelerometer_bandwidth
  • 2: 31 25hz, for accelerometer_bandwidth
  • 3: 62 5hz, for accelerometer_bandwidth
  • 4: 125hz, for accelerometer_bandwidth
  • 5: 250hz, for accelerometer_bandwidth
  • 6: 500hz, for accelerometer_bandwidth
  • 7: 1000hz, for accelerometer_bandwidth

New in version 2.0.5 (Firmware).

BrickIMUV2.set_sensor_fusion_mode
Function ID:

43

Request:
  • mode -- uint8
Response:

no response

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 meanings are defined for the parameters of this function:

  • 0: off, for mode
  • 1: on, for mode
  • 2: on without magnetometer, for mode
  • 3: on without fast magnetometer calibration, for mode

New in version 2.0.5 (Firmware).

BrickIMUV2.get_sensor_fusion_mode
Function ID:

44

Request:

empty payload

Response:
  • mode -- uint8

Returns the sensor fusion mode as set by set_sensor_fusion_mode.

The following meanings are defined for the parameters of this function:

  • 0: off, for mode
  • 1: on, for mode
  • 2: on without magnetometer, for mode
  • 3: on without fast magnetometer calibration, for mode

New in version 2.0.5 (Firmware).

BrickIMUV2.set_spitfp_baudrate_config
Function ID:

231

Request:
  • enable_dynamic_baudrate -- bool
  • minimum_dynamic_baudrate -- uint32
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 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
Function ID:

232

Request:

empty payload

Response:
  • enable_dynamic_baudrate -- bool
  • minimum_dynamic_baudrate -- uint32

Returns the baudrate config, see set_spitfp_baudrate_config.

New in version 2.0.10 (Firmware).

BrickIMUV2.get_send_timeout_count
Function ID:

233

Request:
  • communication_method -- uint8
Response:
  • timeout_count -- uint32

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 meanings are defined for the parameters of this function:

  • 0: none, for communication_method
  • 1: usb, for communication_method
  • 2: spi stack, for communication_method
  • 3: chibi, for communication_method
  • 4: rs485, for communication_method
  • 5: wifi, for communication_method
  • 6: ethernet, for communication_method
  • 7: wifi v2, for communication_method

New in version 2.0.7 (Firmware).

BrickIMUV2.set_spitfp_baudrate
Function ID:

234

Request:
  • bricklet_port -- char
  • baudrate -- uint32
Response:

no response

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
Function ID:

235

Request:
  • bricklet_port -- char
Response:
  • baudrate -- uint32

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

New in version 2.0.5 (Firmware).

BrickIMUV2.get_spitfp_error_count
Function ID:

237

Request:
  • bricklet_port -- char
Response:
  • error_count_ack_checksum -- uint32
  • error_count_message_checksum -- uint32
  • error_count_frame -- uint32
  • error_count_overflow -- uint32

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).

BrickIMUV2.enable_status_led
Function ID:238
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.

BrickIMUV2.disable_status_led
Function ID:239
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.

BrickIMUV2.is_status_led_enabled
Function ID:

240

Request:

empty payload

Response:
  • enabled -- bool

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

BrickIMUV2.get_protocol1_bricklet_name
Function ID:

241

Request:
  • port -- char
Response:
  • protocol_version -- uint8
  • firmware_version -- uint8[3]
  • name -- char[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.

BrickIMUV2.get_chip_temperature
Function ID:

242

Request:

empty payload

Response:
  • temperature -- int16

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
Function ID:243
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!

BrickIMUV2.get_identity
Function ID:

255

Request:

empty payload

Response:
  • uid -- char[8]
  • connected_uid -- char[8]
  • position -- char
  • hardware_version -- uint8[3]
  • firmware_version -- uint8[3]
  • device_identifier -- uint16

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

Callback Configuration Functions

BrickIMUV2.set_acceleration_period
Function ID:

14

Request:
  • period -- uint32
Response:

no response

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
Function ID:

15

Request:

empty payload

Response:
  • period -- uint32

Returns the period as set by set_acceleration_period.

BrickIMUV2.set_magnetic_field_period
Function ID:

16

Request:
  • period -- uint32
Response:

no response

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
Function ID:

17

Request:

empty payload

Response:
  • period -- uint32

Returns the period as set by set_magnetic_field_period.

BrickIMUV2.set_angular_velocity_period
Function ID:

18

Request:
  • period -- uint32
Response:

no response

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
Function ID:

19

Request:

empty payload

Response:
  • period -- uint32

Returns the period as set by set_angular_velocity_period.

BrickIMUV2.set_temperature_period
Function ID:

20

Request:
  • period -- uint32
Response:

no response

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
Function ID:

21

Request:

empty payload

Response:
  • period -- uint32

Returns the period as set by set_temperature_period.

BrickIMUV2.set_orientation_period
Function ID:

22

Request:
  • period -- uint32
Response:

no response

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
Function ID:

23

Request:

empty payload

Response:
  • period -- uint32

Returns the period as set by set_orientation_period.

BrickIMUV2.set_linear_acceleration_period
Function ID:

24

Request:
  • period -- uint32
Response:

no response

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
Function ID:

25

Request:

empty payload

Response:
  • period -- uint32

Returns the period as set by set_linear_acceleration_period.

BrickIMUV2.set_gravity_vector_period
Function ID:

26

Request:
  • period -- uint32
Response:

no response

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
Function ID:

27

Request:

empty payload

Response:
  • period -- uint32

Returns the period as set by set_gravity_vector_period.

BrickIMUV2.set_quaternion_period
Function ID:

28

Request:
  • period -- uint32
Response:

no response

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
Function ID:

29

Request:

empty payload

Response:
  • period -- uint32

Returns the period as set by set_quaternion_period.

BrickIMUV2.set_all_data_period
Function ID:

30

Request:
  • period -- uint32
Response:

no response

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
Function ID:

31

Request:

empty payload

Response:
  • period -- uint32

Returns the period as set by set_all_data_period.

Callbacks

BrickIMUV2.CALLBACK_ACCELERATION
Function ID:

32

Response:
  • x -- int16
  • y -- int16
  • z -- int16

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

BrickIMUV2.CALLBACK_MAGNETIC_FIELD
Function ID:

33

Response:
  • x -- int16
  • y -- int16
  • z -- int16

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

BrickIMUV2.CALLBACK_ANGULAR_VELOCITY
Function ID:

34

Response:
  • x -- int16
  • y -- int16
  • z -- int16

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

BrickIMUV2.CALLBACK_TEMPERATURE
Function ID:

35

Response:
  • temperature -- int8

This callback is triggered periodically with the period that is set by set_temperature_period. The response value is the temperature.

BrickIMUV2.CALLBACK_LINEAR_ACCELERATION
Function ID:

36

Response:
  • x -- int16
  • y -- int16
  • z -- int16

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

BrickIMUV2.CALLBACK_GRAVITY_VECTOR
Function ID:

37

Response:
  • x -- int16
  • y -- int16
  • z -- int16

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

BrickIMUV2.CALLBACK_ORIENTATION
Function ID:

38

Response:
  • heading -- int16
  • roll -- int16
  • pitch -- int16

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

BrickIMUV2.CALLBACK_QUATERNION
Function ID:

39

Response:
  • w -- int16
  • x -- int16
  • y -- int16
  • z -- int16

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

BrickIMUV2.CALLBACK_ALL_DATA
Function ID:

40

Response:
  • acceleration -- int16[3]
  • magnetic_field -- int16[3]
  • angular_velocity -- int16[3]
  • euler_angle -- int16[3]
  • quaternion -- int16[4]
  • linear_acceleration -- int16[3]
  • gravity_vector -- int16[3]
  • temperature -- int8
  • calibration_status -- uint8

This callback is triggered periodically with the period that is set by set_all_data_period. The response values are as for get_all_data.