imu_brick

func (*IMUBrick) AreLedsOn ¶

func (device *IMUBrick) AreLedsOn() (leds bool, err error)

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

func (*IMUBrick) DeregisterAccelerationCallback ¶

func (device *IMUBrick) DeregisterAccelerationCallback(registrationId uint64)

Remove a registered Acceleration callback.

func (*IMUBrick) DeregisterAllDataCallback ¶

func (device *IMUBrick) DeregisterAllDataCallback(registrationId uint64)

Remove a registered All Data callback.

func (*IMUBrick) DeregisterAngularVelocityCallback ¶

func (device *IMUBrick) DeregisterAngularVelocityCallback(registrationId uint64)

Remove a registered Angular Velocity callback.

func (*IMUBrick) DeregisterMagneticFieldCallback ¶

func (device *IMUBrick) DeregisterMagneticFieldCallback(registrationId uint64)

Remove a registered Magnetic Field callback.

func (*IMUBrick) DeregisterOrientationCallback ¶

func (device *IMUBrick) DeregisterOrientationCallback(registrationId uint64)

Remove a registered Orientation callback.

func (*IMUBrick) DeregisterQuaternionCallback ¶

func (device *IMUBrick) DeregisterQuaternionCallback(registrationId uint64)

Remove a registered Quaternion callback.

func (*IMUBrick) DisableStatusLED ¶

func (device *IMUBrick) DisableStatusLED() (err error)

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.

.. versionadded:: 2.3.1$nbsp;(Firmware)

func (*IMUBrick) EnableStatusLED ¶

func (device *IMUBrick) EnableStatusLED() (err error)

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.

.. versionadded:: 2.3.1$nbsp;(Firmware)

func (*IMUBrick) GetAPIVersion ¶

func (device *IMUBrick) GetAPIVersion() [3]uint8

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.

func (*IMUBrick) GetAcceleration ¶

func (device *IMUBrick) GetAcceleration() (x int16, y int16, z int16, err error)

Returns the calibrated acceleration from the accelerometer for the x, y and z axis.

If you want to get the acceleration periodically, it is recommended to use the RegisterAccelerationCallback callback and set the period with SetAccelerationPeriod.

func (*IMUBrick) GetAccelerationPeriod ¶

func (device *IMUBrick) GetAccelerationPeriod() (period uint32, err error)

Returns the period as set by SetAccelerationPeriod.

func (*IMUBrick) GetAccelerationRange ¶

func (device *IMUBrick) GetAccelerationRange() (range_ uint8, err error)

Not implemented yet.

func (*IMUBrick) GetAllData ¶

func (device *IMUBrick) GetAllData() (accX int16, accY int16, accZ int16, magX int16, magY int16, magZ int16, angX int16, angY int16, angZ int16, temperature int16, err error)

Returns the data from GetAcceleration, GetMagneticField and GetAngularVelocity as well as the temperature of the IMU Brick.

If you want to get the data periodically, it is recommended to use the RegisterAllDataCallback callback and set the period with SetAllDataPeriod.

func (*IMUBrick) GetAllDataPeriod ¶

func (device *IMUBrick) GetAllDataPeriod() (period uint32, err error)

Returns the period as set by SetAllDataPeriod.

func (*IMUBrick) GetAngularVelocity ¶

func (device *IMUBrick) GetAngularVelocity() (x int16, y int16, z int16, err error)

Returns the calibrated angular velocity from the gyroscope for the x, y and z axis in °/14.375s (you have to divide by 14.375 to get the value in °/s).

If you want to get the angular velocity periodically, it is recommended to use the RegisterAngularVelocityCallback callback and set the period with SetAngularVelocityPeriod.

func (*IMUBrick) GetAngularVelocityPeriod ¶

func (device *IMUBrick) GetAngularVelocityPeriod() (period uint32, err error)

Returns the period as set by SetAngularVelocityPeriod.

func (*IMUBrick) GetCalibration ¶

func (device *IMUBrick) GetCalibration(typ CalibrationType) (data [10]int16, err error)

Returns the calibration for a given type as set by SetCalibration.

Associated constants:

• CalibrationTypeAccelerometerGain
• CalibrationTypeAccelerometerBias
• CalibrationTypeMagnetometerGain
• CalibrationTypeMagnetometerBias
• CalibrationTypeGyroscopeGain
• CalibrationTypeGyroscopeBias

func (*IMUBrick) GetChipTemperature ¶

func (device *IMUBrick) GetChipTemperature() (temperature int16, err error)

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.

func (*IMUBrick) GetConvergenceSpeed ¶

func (device *IMUBrick) GetConvergenceSpeed() (speed uint16, err error)

Returns the convergence speed as set by SetConvergenceSpeed.

func (*IMUBrick) GetIMUTemperature ¶

func (device *IMUBrick) GetIMUTemperature() (temperature int16, err error)

Returns the temperature of the IMU Brick.

func (*IMUBrick) GetIdentity ¶

func (device *IMUBrick) GetIdentity() (uid string, connectedUid string, position rune, hardwareVersion [3]uint8, firmwareVersion [3]uint8, deviceIdentifier uint16, err error)

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 <device_identifier>`. |device_identifier_constant|

func (*IMUBrick) GetMagneticField ¶

func (device *IMUBrick) GetMagneticField() (x int16, y int16, z int16, err error)

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 RegisterMagneticFieldCallback callback and set the period with SetMagneticFieldPeriod.

func (*IMUBrick) GetMagneticFieldPeriod ¶

func (device *IMUBrick) GetMagneticFieldPeriod() (period uint32, err error)

Returns the period as set by SetMagneticFieldPeriod.

func (*IMUBrick) GetMagnetometerRange ¶

func (device *IMUBrick) GetMagnetometerRange() (range_ uint8, err error)

Not implemented yet.

func (*IMUBrick) GetOrientation ¶

func (device *IMUBrick) GetOrientation() (roll int16, pitch int16, yaw int16, err error)

Returns the current orientation (roll, pitch, yaw) of the IMU Brick as Euler angles. Note that Euler angles always experience a https://en.wikipedia.org/wiki/Gimbal_lock.

We recommend that you use quaternions instead.

The order to sequence in which the orientation values should be applied is roll, yaw, pitch.

If you want to get the orientation periodically, it is recommended to use the RegisterOrientationCallback callback and set the period with SetOrientationPeriod.

func (*IMUBrick) GetOrientationPeriod ¶

func (device *IMUBrick) GetOrientationPeriod() (period uint32, err error)

Returns the period as set by SetOrientationPeriod.

func (*IMUBrick) GetProtocol1BrickletName ¶

func (device *IMUBrick) GetProtocol1BrickletName(port rune) (protocolVersion uint8, firmwareVersion [3]uint8, name string, err error)

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.

func (*IMUBrick) GetQuaternion ¶

func (device *IMUBrick) GetQuaternion() (x float32, y float32, z float32, w float32, err error)

Returns the current orientation (x, y, z, w) of the IMU as https://en.wikipedia.org/wiki/Quaternions_and_spatial_rotation.

You can go from quaternions to Euler angles with the following formula::

xAngle = atan2(2*y*w - 2*x*z, 1 - 2*y*y - 2*z*z)
yAngle = atan2(2*x*w - 2*y*z, 1 - 2*x*x - 2*z*z)
zAngle =  asin(2*x*y + 2*z*w)

This process is not reversible, because of the https://en.wikipedia.org/wiki/Gimbal_lock.

It is also possible to calculate independent angles. You can calculate yaw, pitch and roll in a right-handed vehicle coordinate system according to DIN70000 with::

yaw   =  atan2(2*x*y + 2*w*z, w*w + x*x - y*y - z*z)
pitch = -asin(2*w*y - 2*x*z)
roll  = -atan2(2*y*z + 2*w*x, -w*w + x*x + y*y - z*z))

Converting the quaternions to an OpenGL transformation matrix is possible with the following formula::

matrix = [[1 - 2*(y*y + z*z),     2*(x*y - w*z),     2*(x*z + w*y), 0],
          [    2*(x*y + w*z), 1 - 2*(x*x + z*z),     2*(y*z - w*x), 0],
          [    2*(x*z - w*y),     2*(y*z + w*x), 1 - 2*(x*x + y*y), 0],
          [                0,                 0,                 0, 1]]

If you want to get the quaternions periodically, it is recommended to use the RegisterQuaternionCallback callback and set the period with SetQuaternionPeriod.

func (*IMUBrick) GetQuaternionPeriod ¶

func (device *IMUBrick) GetQuaternionPeriod() (period uint32, err error)

Returns the period as set by SetQuaternionPeriod.

func (*IMUBrick) GetResponseExpected ¶

func (device *IMUBrick) GetResponseExpected(functionID Function) (bool, error)

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 SetResponseExpected. 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 sent and errors are silently ignored, because they cannot be detected.

See SetResponseExpected for the list of function ID constants available for this function.

func (*IMUBrick) GetSPITFPBaudrate ¶

func (device *IMUBrick) GetSPITFPBaudrate(brickletPort rune) (baudrate uint32, err error)

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

.. versionadded:: 2.3.3$nbsp;(Firmware)

func (*IMUBrick) GetSPITFPBaudrateConfig ¶

func (device *IMUBrick) GetSPITFPBaudrateConfig() (enableDynamicBaudrate bool, minimumDynamicBaudrate uint32, err error)

Returns the baudrate config, see SetSPITFPBaudrateConfig.

.. versionadded:: 2.3.5$nbsp;(Firmware)

func (*IMUBrick) GetSPITFPErrorCount ¶

func (device *IMUBrick) GetSPITFPErrorCount(brickletPort rune) (errorCountACKChecksum uint32, errorCountMessageChecksum uint32, errorCountFrame uint32, errorCountOverflow uint32, err error)

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.

.. versionadded:: 2.3.3$nbsp;(Firmware)

func (*IMUBrick) GetSendTimeoutCount ¶

func (device *IMUBrick) GetSendTimeoutCount(communicationMethod CommunicationMethod) (timeoutCount uint32, err error)

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.

.. versionadded:: 2.3.3$nbsp;(Firmware)

Associated constants:

• CommunicationMethodNone
• CommunicationMethodUSB
• CommunicationMethodSPIStack
• CommunicationMethodChibi
• CommunicationMethodRS485
• CommunicationMethodWIFI
• CommunicationMethodEthernet
• CommunicationMethodWIFIV2

func (*IMUBrick) IsOrientationCalculationOn ¶

func (device *IMUBrick) IsOrientationCalculationOn() (orientationCalculationOn bool, err error)

Returns *true* if the orientation calculation of the IMU Brick is on, *false* otherwise.

.. versionadded:: 2.0.2$nbsp;(Firmware)

func (*IMUBrick) IsStatusLEDEnabled ¶

func (device *IMUBrick) IsStatusLEDEnabled() (enabled bool, err error)

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

.. versionadded:: 2.3.1$nbsp;(Firmware)

func (*IMUBrick) LedsOff ¶

func (device *IMUBrick) LedsOff() (err error)

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

func (*IMUBrick) LedsOn ¶

func (device *IMUBrick) LedsOn() (err error)

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

func (*IMUBrick) OrientationCalculationOff ¶

func (device *IMUBrick) OrientationCalculationOff() (err error)

Turns the orientation calculation of the IMU Brick off.

If the calculation is off, GetOrientation will return the last calculated value until the calculation is turned on again.

The trigonometric functions that are needed to calculate the orientation are very expensive. We recommend to turn the orientation calculation off if the orientation is not needed, to free calculation time for the sensor fusion algorithm.

As default the calculation is on.

.. versionadded:: 2.0.2$nbsp;(Firmware)

func (*IMUBrick) OrientationCalculationOn ¶

func (device *IMUBrick) OrientationCalculationOn() (err error)

Turns the orientation calculation of the IMU Brick on.

As default the calculation is on.

.. versionadded:: 2.0.2$nbsp;(Firmware)

func (*IMUBrick) ReadBrickletPlugin ¶

func (device *IMUBrick) ReadBrickletPlugin(port rune, offset uint8) (chunk [32]uint8, err error)

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.

func (*IMUBrick) RegisterAccelerationCallback ¶

func (device *IMUBrick) RegisterAccelerationCallback(fn func(int16, int16, int16)) uint64

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

func (*IMUBrick) RegisterAllDataCallback ¶

func (device *IMUBrick) RegisterAllDataCallback(fn func(int16, int16, int16, int16, int16, int16, int16, int16, int16, int16)) uint64

This callback is triggered periodically with the period that is set by SetAllDataPeriod. The parameters are the acceleration, the magnetic field and the angular velocity for the x, y and z axis as well as the temperature of the IMU Brick.

func (*IMUBrick) RegisterAngularVelocityCallback ¶

func (device *IMUBrick) RegisterAngularVelocityCallback(fn func(int16, int16, int16)) uint64

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

func (*IMUBrick) RegisterMagneticFieldCallback ¶

func (device *IMUBrick) RegisterMagneticFieldCallback(fn func(int16, int16, int16)) uint64

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

func (*IMUBrick) RegisterOrientationCallback ¶

func (device *IMUBrick) RegisterOrientationCallback(fn func(int16, int16, int16)) uint64

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

func (*IMUBrick) RegisterQuaternionCallback ¶

func (device *IMUBrick) RegisterQuaternionCallback(fn func(float32, float32, float32, float32)) uint64

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

func (*IMUBrick) Reset ¶

func (device *IMUBrick) Reset() (err error)

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!

func (*IMUBrick) SetAccelerationPeriod ¶

func (device *IMUBrick) SetAccelerationPeriod(period uint32) (err error)

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

func (*IMUBrick) SetAccelerationRange ¶

func (device *IMUBrick) SetAccelerationRange(range_ uint8) (err error)

Not implemented yet.

func (*IMUBrick) SetAllDataPeriod ¶

func (device *IMUBrick) SetAllDataPeriod(period uint32) (err error)

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

func (*IMUBrick) SetAngularVelocityPeriod ¶

func (device *IMUBrick) SetAngularVelocityPeriod(period uint32) (err error)

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

func (*IMUBrick) SetCalibration ¶

func (device *IMUBrick) SetCalibration(typ CalibrationType, data [10]int16) (err error)

There are several different types that can be calibrated:

Type| Description| Values
--- | --- | ---
0|    Accelerometer Gain| ``[mul x| mul y| mul z| div x| div y| div z| 0| 0| 0| 0]``
1|    Accelerometer Bias| ``[bias x| bias y| bias z| 0| 0| 0| 0| 0| 0| 0]``
2|    Magnetometer Gain|  ``[mul x| mul y| mul z| div x| div y| div z| 0| 0| 0| 0]``
3|    Magnetometer Bias|  ``[bias x| bias y| bias z| 0| 0| 0| 0| 0| 0| 0]``
4|    Gyroscope Gain|     ``[mul x| mul y| mul z| div x| div y| div z| 0| 0| 0| 0]``
5|    Gyroscope Bias|     ``[bias xl| bias yl| bias zl| temp l| bias xh| bias yh| bias zh| temp h| 0| 0]``

The calibration via gain and bias is done with the following formula::

new_value = (bias + orig_value) * gain_mul / gain_div

If you really want to write your own calibration software, please keep in mind that you first have to undo the old calibration (set bias to 0 and gain to 1/1) and that you have to average over several thousand values to obtain a usable result in the end.

The gyroscope bias is highly dependent on the temperature, so you have to calibrate the bias two times with different temperatures. The values “xl“, “yl“, “zl“ and “temp l“ are the bias for “x“, “y“, “z“ and the corresponding temperature for a low temperature. The values “xh“, “yh“, “zh“ and “temp h“ are the same for a high temperatures. The temperature difference should be at least 5°C. If you have a temperature where the IMU Brick is mostly used, you should use this temperature for one of the sampling points.

Note

We highly recommend that you use the Brick Viewer to calibrate your
IMU Brick.

Associated constants:

• CalibrationTypeAccelerometerGain
• CalibrationTypeAccelerometerBias
• CalibrationTypeMagnetometerGain
• CalibrationTypeMagnetometerBias
• CalibrationTypeGyroscopeGain
• CalibrationTypeGyroscopeBias

func (*IMUBrick) SetConvergenceSpeed ¶

func (device *IMUBrick) SetConvergenceSpeed(speed uint16) (err error)

Sets the convergence speed of the IMU Brick. The convergence speed determines how the different sensor measurements are fused.

If the orientation of the IMU Brick is off by 10° and the convergence speed is set to 20°/s, it will take 0.5s until the orientation is corrected. However, if the correct orientation is reached and the convergence speed is too high, the orientation will fluctuate with the fluctuations of the accelerometer and the magnetometer.

If you set the convergence speed to 0, practically only the gyroscope is used to calculate the orientation. This gives very smooth movements, but errors of the gyroscope will not be corrected. If you set the convergence speed to something above 500, practically only the magnetometer and the accelerometer are used to calculate the orientation. In this case the movements are abrupt and the values will fluctuate, but there won't be any errors that accumulate over time.

In an application with high angular velocities, we recommend a high convergence speed, so the errors of the gyroscope can be corrected fast. In applications with only slow movements we recommend a low convergence speed. You can change the convergence speed on the fly. So it is possible (and recommended) to increase the convergence speed before an abrupt movement and decrease it afterwards again.

You might want to play around with the convergence speed in the Brick Viewer to get a feeling for a good value for your application.

func (*IMUBrick) SetMagneticFieldPeriod ¶

func (device *IMUBrick) SetMagneticFieldPeriod(period uint32) (err error)

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

func (*IMUBrick) SetMagnetometerRange ¶

func (device *IMUBrick) SetMagnetometerRange(range_ uint8) (err error)

Not implemented yet.

func (*IMUBrick) SetOrientationPeriod ¶

func (device *IMUBrick) SetOrientationPeriod(period uint32) (err error)

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

func (*IMUBrick) SetQuaternionPeriod ¶

func (device *IMUBrick) SetQuaternionPeriod(period uint32) (err error)

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

func (*IMUBrick) SetResponseExpected ¶

func (device *IMUBrick) SetResponseExpected(functionID Function, responseExpected bool) error

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 sent and errors are silently ignored, because they cannot be detected.

func (*IMUBrick) SetResponseExpectedAll ¶

func (device *IMUBrick) SetResponseExpectedAll(responseExpected bool)

Changes the response expected flag for all setter and callback configuration functions of this device at once.

func (*IMUBrick) SetSPITFPBaudrate ¶

func (device *IMUBrick) SetSPITFPBaudrate(brickletPort rune, baudrate uint32) (err error)

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 GetSPITFPErrorCount) you can decrease the baudrate.

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

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.

.. versionadded:: 2.3.3$nbsp;(Firmware)

func (*IMUBrick) SetSPITFPBaudrateConfig ¶

func (device *IMUBrick) SetSPITFPBaudrateConfig(enableDynamicBaudrate bool, minimumDynamicBaudrate uint32) (err error)

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 SetSPITFPBaudrate. If the dynamic baudrate is disabled, the baudrate as set by SetSPITFPBaudrate will be used statically.

.. versionadded:: 2.3.5$nbsp;(Firmware)

func (*IMUBrick) WriteBrickletPlugin ¶

func (device *IMUBrick) WriteBrickletPlugin(port rune, offset uint8, chunk [32]uint8) (err error)

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.