C# - IMU Brick 2.0

Note

This Brick is currently in the prototype stage and the software/hardware as well as the documentation is in an incomplete state.

This is the description of the C# 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 C# API bindings is part of their general description.

Examples

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

API

Generally, every method of the C# bindings that returns a value can throw a Tinkerforge.TimeoutException. This exception gets thrown if the device did not respond. If a cable based connection is used, it is unlikely that this exception gets thrown (assuming nobody plugs the device out). However, if a wireless connection is used, timeouts will occur if the distance to the device gets too big.

Since C# does not support multiple return values directly, we use the out keyword to return multiple values from a method.

The namespace for all Brick/Bricklet bindings and the IPConnection is Tinkerforge.*.

All methods listed below are thread-safe.

Basic Functions

public class BrickIMUV2(String uid, IPConnection ipcon)

Creates an object with the unique device ID uid:

BrickIMUV2 imuV2 = new BrickIMUV2("YOUR_DEVICE_UID", ipcon);

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

public void GetAllData(out short[] acceleration, out short[] magneticField, out short[] angularVelocity, out short[] eulerAngle, out short[] quaternion, out short[] linearAcceleration, out short[] gravityVector, out short temperature, out byte calibrationStatus)

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 AllData and set the period with SetAllDataPeriod().

public void LedsOn()

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

public void LedsOff()

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

public bool AreLedsOn()

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

Advanced Functions

public void GetAcceleration(out short x, out short y, out short z)

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 and set the period with SetAccelerationPeriod().

public void GetMagneticField(out short x, out short y, out short z)

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 MagneticField and set the period with SetMagneticFieldPeriod().

public void GetAngularVelocity(out short x, out short y, out short z)

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 AngularVelocity and set the period with SetAngularVelocityPeriod().

public short GetTemperature()

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

public void GetOrientation(out short heading, out short roll, out short pitch)

Returns the current orientation (heading, roll, pitch) of the IMU Brick as Euler angles in 1/16 degree. Note that Euler angles always experience a gimbal lock.

We recommend that you use quaternions instead.

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 and set the period with SetOrientationPeriod().

public void GetLinearAcceleration(out short x, out short y, out short z)

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 GetGravityVector().

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

public void GetGravityVector(out short x, out short y, out short z)

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 GetLinearAcceleration().

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

public void GetQuaternion(out short w, out short x, out short y, out short z)

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 and set the period with SetQuaternionPeriod().

public bool SaveCalibration()

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.

public byte[] GetAPIVersion()

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.

public bool GetResponseExpected(byte functionId)

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

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

public void SetResponseExpected(byte functionId, bool responseExpected)

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 and callbacks it is always disabled.

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_ENABLE_STATUS_LED = 238
  • BrickIMUV2.FUNCTION_DISABLE_STATUS_LED = 239
  • BrickIMUV2.FUNCTION_RESET = 243
public void SetResponseExpectedAll(bool responseExpected)

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

public void EnableStatusLED()

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.

public void DisableStatusLED()

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.

public bool IsStatusLEDEnabled()

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

public void GetProtocol1BrickletName(char port, out byte protocolVersion, out byte[] firmwareVersion, out string name)

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.

public short GetChipTemperature()

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.

public void Reset()

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!

public void GetIdentity(out string uid, out string connectedUid, out char position, out byte[] hardwareVersion, out byte[] firmwareVersion, out int deviceIdentifier)

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.

Callback Configuration Functions

public void SetAccelerationPeriod(long period)

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

The default value is 0.

public long GetAccelerationPeriod()

Returns the period as set by SetAccelerationPeriod().

public void SetMagneticFieldPeriod(long period)

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

public long GetMagneticFieldPeriod()

Returns the period as set by SetMagneticFieldPeriod().

public void SetAngularVelocityPeriod(long period)

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

public long GetAngularVelocityPeriod()

Returns the period as set by SetAngularVelocityPeriod().

public void SetTemperaturePeriod(long period)

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

public long GetTemperaturePeriod()

Returns the period as set by SetTemperaturePeriod().

public void SetOrientationPeriod(long period)

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

public long GetOrientationPeriod()

Returns the period as set by SetOrientationPeriod().

public void SetLinearAccelerationPeriod(long period)

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

public long GetLinearAccelerationPeriod()

Returns the period as set by SetLinearAccelerationPeriod().

public void SetGravityVectorPeriod(long period)

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

public long GetGravityVectorPeriod()

Returns the period as set by SetGravityVectorPeriod().

public void SetQuaternionPeriod(long period)

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

public long GetQuaternionPeriod()

Returns the period as set by SetQuaternionPeriod().

public void SetAllDataPeriod(long period)

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

public long GetAllDataPeriod()

Returns the period as set by SetAllDataPeriod().

Callbacks

Callbacks can be registered to receive time critical or recurring data from the device. The registration is done by appending your callback handler to the corresponding event:

void Callback(BrickIMUV2 sender, int value)
{
    System.Console.WriteLine("Value: " + value);
}

imuV2.ExampleCallback += Callback;

The available events 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.

public event Acceleration(BrickIMUV2 sender, short x, short y, short z)

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.

public event MagneticField(BrickIMUV2 sender, short x, short y, short z)

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.

public event AngularVelocity(BrickIMUV2 sender, short x, short y, short z)

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.

public event Temperature(BrickIMUV2 sender, short temperature)

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

public event LinearAcceleration(BrickIMUV2 sender, short x, short y, short z)

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

public event GravityVector(BrickIMUV2 sender, short x, short y, short z)

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

public event Orientation(BrickIMUV2 sender, short heading, short roll, short pitch)

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

public event Quaternion(BrickIMUV2 sender, short w, short x, short y, short z)

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.

public event AllData(BrickIMUV2 sender, short[] acceleration, short[] magneticField, short[] angularVelocity, short[] eulerAngle, short[] quaternion, short[] linearAcceleration, short[] gravityVector, short temperature, byte calibrationStatus)

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

Constants

public int DEVICE_IDENTIFIER

This constant is used to identify a IMU Brick 2.0.

The GetIdentity() function and the EnumerateCallback callback of the IP Connection have a deviceIdentifier parameter to specify the Brick's or Bricklet's type.

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