Software / API Bindings / JavaScript / API Reference and Examples / Bricks (Discontinued) / IMU Brick

JavaScript - IMU Brick¶

This is the description of the JavaScript API bindings for the IMU Brick. General information and technical specifications for the IMU Brick are summarized in its hardware description.

An installation guide for the JavaScript API bindings is part of their general description.

Examples¶

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

Simple (Node.js)¶

Download (ExampleSimple.js)

var Tinkerforge = require('tinkerforge');

var HOST = 'localhost';
var PORT = 4223;
var UID = 'XXYYZZ'; // Change XXYYZZ to the UID of your IMU Brick

var ipcon = new Tinkerforge.IPConnection(); // Create IP connection
var imu = new Tinkerforge.BrickIMU(UID, ipcon); // Create device object

ipcon.connect(HOST, PORT,
    function (error) {
        console.log('Error: ' + error);
    }
); // Connect to brickd
// Don't use device before ipcon is connected

ipcon.on(Tinkerforge.IPConnection.CALLBACK_CONNECTED,
    function (connectReason) {
        // Get current quaternion
        imu.getQuaternion(
            function (x, y, z, w) {
                console.log('Quaternion [X]: ' + x);
                console.log('Quaternion [Y]: ' + y);
                console.log('Quaternion [Z]: ' + z);
                console.log('Quaternion [W]: ' + w);
            },
            function (error) {
                console.log('Error: ' + error);
            }
        );
    }
);

console.log('Press key to exit');
process.stdin.on('data',
    function (data) {
        ipcon.disconnect();
        process.exit(0);
    }
);

Callback (Node.js)¶

Download (ExampleCallback.js)

var Tinkerforge = require('tinkerforge');

var HOST = 'localhost';
var PORT = 4223;
var UID = 'XXYYZZ'; // Change XXYYZZ to the UID of your IMU Brick

var ipcon = new Tinkerforge.IPConnection(); // Create IP connection
var imu = new Tinkerforge.BrickIMU(UID, ipcon); // Create device object

ipcon.connect(HOST, PORT,
    function (error) {
        console.log('Error: ' + error);
    }
); // Connect to brickd
// Don't use device before ipcon is connected

ipcon.on(Tinkerforge.IPConnection.CALLBACK_CONNECTED,
    function (connectReason) {
        // Set period for quaternion callback to 1s (1000ms)
        imu.setQuaternionPeriod(1000);
    }
);

// Register quaternion callback
imu.on(Tinkerforge.BrickIMU.CALLBACK_QUATERNION,
    // Callback function for quaternion callback
    function (x, y, z, w) {
        console.log('Quaternion [X]: ' + x);
        console.log('Quaternion [Y]: ' + y);
        console.log('Quaternion [Z]: ' + z);
        console.log('Quaternion [W]: ' + w);
        console.log();
    }
);

console.log('Press key to exit');
process.stdin.on('data',
    function (data) {
        ipcon.disconnect();
        process.exit(0);
    }
);

Simple (HTML)¶

Download (ExampleSimple.html), Test (ExampleSimple.html)

<!DOCTYPE html>
<html>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <head>
        <title>Tinkerforge | JavaScript Example</title>
    </head>
    <body>
        <div style="text-align:center;">
            <h1>IMU Brick Simple Example</h1>
            <p>
                <input value="localhost" id="host" type="text" size="20">:
                <input value="4280" id="port" type="text" size="5">,
                <input value="uid" id="uid" type="text" size="5">
                <input value="Start Example" id="start" type="button" onclick="startExample();">
            </p>
            <p>
                <textarea readonly id="text" cols="80" rows="24" style="resize:none;"
                          >Press "Start Example" to begin ...</textarea>
            </p>
        </div>
        <script src="./Tinkerforge.js" type='text/javascript'></script>
        <script type='text/javascript'>
            var ipcon;
            var textArea = document.getElementById("text");
            function startExample() {
                textArea.value = "";
                var HOST = document.getElementById("host").value;
                var PORT = parseInt(document.getElementById("port").value);
                var UID = document.getElementById("uid").value;
                if(ipcon !== undefined) {
                    ipcon.disconnect();
                }
                ipcon = new Tinkerforge.IPConnection(); // Create IP connection
                var imu = new Tinkerforge.BrickIMU(UID, ipcon); // Create device object
                ipcon.connect(HOST, PORT,
                    function(error) {
                        textArea.value += 'Error: ' + error + '\n';
                    }
                ); // Connect to brickd
                // Don't use device before ipcon is connected

                ipcon.on(Tinkerforge.IPConnection.CALLBACK_CONNECTED,
                    function (connectReason) {
                        // Get current quaternion
                        imu.getQuaternion(
                            function (x, y, z, w) {
                                textArea.value += 'Quaternion [X]: ' + x + '\n';
                                textArea.value += 'Quaternion [Y]: ' + y + '\n';
                                textArea.value += 'Quaternion [Z]: ' + z + '\n';
                                textArea.value += 'Quaternion [W]: ' + w + '\n';
                            },
                            function (error) {
                                textArea.value += 'Error: ' + error + '\n';
                            }
                        );
                    }
                );
            }
        </script>
    </body>
</html>

Callback (HTML)¶

Download (ExampleCallback.html), Test (ExampleCallback.html)

<!DOCTYPE html>
<html>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <head>
        <title>Tinkerforge | JavaScript Example</title>
    </head>
    <body>
        <div style="text-align:center;">
            <h1>IMU Brick Callback Example</h1>
            <p>
                <input value="localhost" id="host" type="text" size="20">:
                <input value="4280" id="port" type="text" size="5">,
                <input value="uid" id="uid" type="text" size="5">
                <input value="Start Example" id="start" type="button" onclick="startExample();">
            </p>
            <p>
                <textarea readonly id="text" cols="80" rows="24" style="resize:none;"
                          >Press "Start Example" to begin ...</textarea>
            </p>
        </div>
        <script src="./Tinkerforge.js" type='text/javascript'></script>
        <script type='text/javascript'>
            var ipcon;
            var textArea = document.getElementById("text");
            function startExample() {
                textArea.value = "";
                var HOST = document.getElementById("host").value;
                var PORT = parseInt(document.getElementById("port").value);
                var UID = document.getElementById("uid").value;
                if(ipcon !== undefined) {
                    ipcon.disconnect();
                }
                ipcon = new Tinkerforge.IPConnection(); // Create IP connection
                var imu = new Tinkerforge.BrickIMU(UID, ipcon); // Create device object
                ipcon.connect(HOST, PORT,
                    function(error) {
                        textArea.value += 'Error: ' + error + '\n';
                    }
                ); // Connect to brickd
                // Don't use device before ipcon is connected

                ipcon.on(Tinkerforge.IPConnection.CALLBACK_CONNECTED,
                    function (connectReason) {
                        // Set period for quaternion callback to 1s (1000ms)
                        imu.setQuaternionPeriod(1000);
                    }
                );

                // Register quaternion callback
                imu.on(Tinkerforge.BrickIMU.CALLBACK_QUATERNION,
                    // Callback function for quaternion callback
                    function (x, y, z, w) {
                        textArea.value += 'Quaternion [X]: ' + x + '\n';
                        textArea.value += 'Quaternion [Y]: ' + y + '\n';
                        textArea.value += 'Quaternion [Z]: ' + z + '\n';
                        textArea.value += 'Quaternion [W]: ' + w + '\n';
                        textArea.value += '\n';
                        textArea.scrollTop = textArea.scrollHeight;
                    }
                );
            }
        </script>
    </body>
</html>

API¶

Generally, every function of the JavaScript bindings can take two optional parameters, returnCallback and errorCallback. These are two user defined callback functions. The returnCallback function is called with the results as arguments, if the function returns its results asynchronously. The errorCallback is called with an error code in case of an error. The error code can be one of the following values:

IPConnection.ERROR_ALREADY_CONNECTED = 11
IPConnection.ERROR_NOT_CONNECTED = 12
IPConnection.ERROR_CONNECT_FAILED = 13
IPConnection.ERROR_INVALID_FUNCTION_ID = 21
IPConnection.ERROR_TIMEOUT = 31
IPConnection.ERROR_INVALID_PARAMETER = 41
IPConnection.ERROR_FUNCTION_NOT_SUPPORTED = 42
IPConnection.ERROR_UNKNOWN_ERROR = 43
IPConnection.ERROR_STREAM_OUT_OF_SYNC = 51
IPConnection.ERROR_NON_ASCII_CHAR_IN_SECRET = 71
IPConnection.ERROR_WRONG_DEVICE_TYPE = 81
IPConnection.ERROR_DEVICE_REPLACED = 82
IPConnection.ERROR_WRONG_RESPONSE_LENGTH = 83
IPConnection.ERROR_INT64_NOT_SUPPORTED = 91

The namespace for the JavaScript bindings is Tinkerforge.*.

Basic Functions¶

new BrickIMU(uid, ipcon)¶

Parameters:	uid – Type: string ipcon – Type: IPConnection
Returns:	imu – Type: BrickIMU

Creates an object with the unique device ID uid:

var imu = new BrickIMU("YOUR_DEVICE_UID", ipcon);

This object can then be used after the IP Connection is connected.

BrickIMU.getOrientation([returnCallback][, errorCallback])¶

Callback Parameters:	roll – Type: int, Unit: 1/100 °, Range: [-18000 to 18000] pitch – Type: int, Unit: 1/100 °, Range: [-18000 to 18000] yaw – Type: int, Unit: 1/100 °, Range: [-18000 to 18000]
Returns:	undefined

Returns the current orientation (roll, pitch, yaw) of the IMU Brick as Euler angles. Note that Euler angles always experience a 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 CALLBACK_ORIENTATION callback and set the period with setOrientationPeriod().

BrickIMU.getQuaternion([returnCallback][, errorCallback])¶

Callback Parameters:	x – Type: float, Range: [-1.0 to 1.0] y – Type: float, Range: [-1.0 to 1.0] z – Type: float, Range: [-1.0 to 1.0] w – Type: float, Range: [-1.0 to 1.0]
Returns:	undefined

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

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 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 CALLBACK_QUATERNION callback and set the period with setQuaternionPeriod().

BrickIMU.ledsOn([returnCallback][, errorCallback])¶

Callback Parameters:	undefined
Returns:	undefined

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

BrickIMU.ledsOff([returnCallback][, errorCallback])¶

Callback Parameters:	undefined
Returns:	undefined

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

BrickIMU.areLedsOn([returnCallback][, errorCallback])¶

Callback Parameters:	leds – Type: boolean, Default: true
Returns:	undefined

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

BrickIMU.setConvergenceSpeed(speed[, returnCallback][, errorCallback])¶

Parameters:	speed – Type: int, Unit: 1 °/s, Range: [0 to 2¹⁶ - 1], Default: 30
Callback Parameters:	undefined
Returns:	undefined

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.

BrickIMU.getConvergenceSpeed([returnCallback][, errorCallback])¶

Callback Parameters:	speed – Type: int, Unit: 1 °/s, Range: [0 to 2¹⁶ - 1], Default: 30
Returns:	undefined

Returns the convergence speed as set by setConvergenceSpeed().

Advanced Functions¶

BrickIMU.getAcceleration([returnCallback][, errorCallback])¶

Callback Parameters:	x – Type: int, Unit: 1/1000 gₙ, Range: [-2¹⁵ to 2¹⁵ - 1] y – Type: int, Unit: 1/1000 gₙ, Range: [-2¹⁵ to 2¹⁵ - 1] z – Type: int, Unit: 1/1000 gₙ, Range: [-2¹⁵ to 2¹⁵ - 1]
Returns:	undefined

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 CALLBACK_ACCELERATION callback and set the period with setAccelerationPeriod().

BrickIMU.getMagneticField([returnCallback][, errorCallback])¶

Callback Parameters:	x – Type: int, Unit: 1/10 µT, Range: [-2¹⁵ to 2¹⁵ - 1] y – Type: int, Unit: 1/10 µT, Range: [-2¹⁵ to 2¹⁵ - 1] z – Type: int, Unit: 1/10 µT, Range: [-2¹⁵ to 2¹⁵ - 1]
Returns:	undefined

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 CALLBACK_MAGNETIC_FIELD callback and set the period with setMagneticFieldPeriod().

BrickIMU.getAngularVelocity([returnCallback][, errorCallback])¶

Callback Parameters:	x – Type: int, Unit: 8/115 °/s, Range: [-28750 to 28750] y – Type: int, Unit: 8/115 °/s, Range: [-28750 to 28750] z – Type: int, Unit: 8/115 °/s, Range: [-28750 to 28750]
Returns:	undefined

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 CALLBACK_ANGULAR_VELOCITY callback and set the period with setAngularVelocityPeriod().

BrickIMU.getAllData([returnCallback][, errorCallback])¶

Callback Parameters:

Callback Parameters:	accX – Type: int, Unit: 1/1000 gₙ, Range: [-2¹⁵ to 2¹⁵ - 1] accY – Type: int, Unit: 1/1000 gₙ, Range: [-2¹⁵ to 2¹⁵ - 1] accZ – Type: int, Unit: 1/1000 gₙ, Range: [-2¹⁵ to 2¹⁵ - 1] magX – Type: int, Unit: 1/10 µT, Range: [-2¹⁵ to 2¹⁵ - 1] magY – Type: int, Unit: 1/10 µT, Range: [-2¹⁵ to 2¹⁵ - 1] magZ – Type: int, Unit: 1/10 µT, Range: [-2¹⁵ to 2¹⁵ - 1] angX – Type: int, Unit: 8/115 °/s, Range: [-28750 to 28750] angY – Type: int, Unit: 8/115 °/s, Range: [-28750 to 28750] angZ – Type: int, Unit: 8/115 °/s, Range: [-28750 to 28750] temperature – Type: int, Unit: 1/100 °C, Range: [-2¹⁵ to 2¹⁵ - 1]
Returns:	undefined

accX – Type: int, Unit: 1/1000 gₙ, Range: [-2¹⁵ to 2¹⁵ - 1]
accY – Type: int, Unit: 1/1000 gₙ, Range: [-2¹⁵ to 2¹⁵ - 1]
accZ – Type: int, Unit: 1/1000 gₙ, Range: [-2¹⁵ to 2¹⁵ - 1]
magX – Type: int, Unit: 1/10 µT, Range: [-2¹⁵ to 2¹⁵ - 1]
magY – Type: int, Unit: 1/10 µT, Range: [-2¹⁵ to 2¹⁵ - 1]
magZ – Type: int, Unit: 1/10 µT, Range: [-2¹⁵ to 2¹⁵ - 1]
angX – Type: int, Unit: 8/115 °/s, Range: [-28750 to 28750]
angY – Type: int, Unit: 8/115 °/s, Range: [-28750 to 28750]
angZ – Type: int, Unit: 8/115 °/s, Range: [-28750 to 28750]
temperature – Type: int, Unit: 1/100 °C, Range: [-2¹⁵ to 2¹⁵ - 1]

Returns:

undefined

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 CALLBACK_ALL_DATA callback and set the period with setAllDataPeriod().

BrickIMU.getIMUTemperature([returnCallback][, errorCallback])¶

Callback Parameters:	temperature – Type: int, Unit: 1/100 °C, Range: [-2¹⁵ to 2¹⁵ - 1]
Returns:	undefined

Returns the temperature of the IMU Brick.

BrickIMU.setAccelerationRange(range[, returnCallback][, errorCallback])¶

Parameters:	range – Type: int, Range: [0 to 255]
Callback Parameters:	undefined
Returns:	undefined

Not implemented yet.

BrickIMU.getAccelerationRange([returnCallback][, errorCallback])¶

Callback Parameters:	range – Type: int, Range: [0 to 255]
Returns:	undefined

Not implemented yet.

BrickIMU.setMagnetometerRange(range[, returnCallback][, errorCallback])¶

Parameters:	range – Type: int, Range: [0 to 255]
Callback Parameters:	undefined
Returns:	undefined

Not implemented yet.

BrickIMU.getMagnetometerRange([returnCallback][, errorCallback])¶

Callback Parameters:	range – Type: int, Range: [0 to 255]
Returns:	undefined

Not implemented yet.

BrickIMU.setCalibration(typ, data[, returnCallback][, errorCallback])¶

Parameters:	typ – Type: int, Range: See constants data – Type: [int, ...], Length: 10, Range: [-2¹⁵ to 2¹⁵ - 1]
Callback Parameters:	undefined
Returns:	undefined

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.

The following constants are available for this function:

For typ:

BrickIMU.CALIBRATION_TYPE_ACCELEROMETER_GAIN = 0
BrickIMU.CALIBRATION_TYPE_ACCELEROMETER_BIAS = 1
BrickIMU.CALIBRATION_TYPE_MAGNETOMETER_GAIN = 2
BrickIMU.CALIBRATION_TYPE_MAGNETOMETER_BIAS = 3
BrickIMU.CALIBRATION_TYPE_GYROSCOPE_GAIN = 4
BrickIMU.CALIBRATION_TYPE_GYROSCOPE_BIAS = 5

BrickIMU.getCalibration(typ[, returnCallback][, errorCallback])¶

Parameters:	typ – Type: int, Range: See constants
Callback Parameters:	data – Type: [int, ...], Length: 10, Range: [-2¹⁵ to 2¹⁵ - 1]
Returns:	undefined

Returns the calibration for a given type as set by setCalibration().

The following constants are available for this function:

For typ:

BrickIMU.CALIBRATION_TYPE_ACCELEROMETER_GAIN = 0
BrickIMU.CALIBRATION_TYPE_ACCELEROMETER_BIAS = 1
BrickIMU.CALIBRATION_TYPE_MAGNETOMETER_GAIN = 2
BrickIMU.CALIBRATION_TYPE_MAGNETOMETER_BIAS = 3
BrickIMU.CALIBRATION_TYPE_GYROSCOPE_GAIN = 4
BrickIMU.CALIBRATION_TYPE_GYROSCOPE_BIAS = 5

BrickIMU.orientationCalculationOn([returnCallback][, errorCallback])¶

Callback Parameters:	undefined
Returns:	undefined

Turns the orientation calculation of the IMU Brick on.

As default the calculation is on.

New in version 2.0.2 (Firmware).

BrickIMU.orientationCalculationOff([returnCallback][, errorCallback])¶

Callback Parameters:	undefined
Returns:	undefined

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.

New in version 2.0.2 (Firmware).

BrickIMU.isOrientationCalculationOn([returnCallback][, errorCallback])¶

Callback Parameters:	orientationCalculationOn – Type: boolean, Default: true
Returns:	undefined

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

New in version 2.0.2 (Firmware).

BrickIMU.setSPITFPBaudrateConfig(enableDynamicBaudrate, minimumDynamicBaudrate[, returnCallback][, errorCallback])¶

Parameters:	enableDynamicBaudrate – Type: boolean, Default: true minimumDynamicBaudrate – Type: int, Unit: 1 Bd, Range: [400000 to 2000000], Default: 400000
Callback Parameters:	undefined
Returns:	undefined

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.

New in version 2.3.5 (Firmware).

BrickIMU.getSPITFPBaudrateConfig([returnCallback][, errorCallback])¶

Callback Parameters:	enableDynamicBaudrate – Type: boolean, Default: true minimumDynamicBaudrate – Type: int, Unit: 1 Bd, Range: [400000 to 2000000], Default: 400000
Returns:	undefined

Returns the baudrate config, see setSPITFPBaudrateConfig().

New in version 2.3.5 (Firmware).

BrickIMU.getSendTimeoutCount(communicationMethod[, returnCallback][, errorCallback])¶

Parameters:	communicationMethod – Type: int, Range: See constants
Callback Parameters:	timeoutCount – Type: int, Range: [0 to 2³² - 1]
Returns:	undefined

Returns the timeout count for the different communication methods.

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

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

The following constants are available for this function:

For communication_method:

BrickIMU.COMMUNICATION_METHOD_NONE = 0
BrickIMU.COMMUNICATION_METHOD_USB = 1
BrickIMU.COMMUNICATION_METHOD_SPI_STACK = 2
BrickIMU.COMMUNICATION_METHOD_CHIBI = 3
BrickIMU.COMMUNICATION_METHOD_RS485 = 4
BrickIMU.COMMUNICATION_METHOD_WIFI = 5
BrickIMU.COMMUNICATION_METHOD_ETHERNET = 6
BrickIMU.COMMUNICATION_METHOD_WIFI_V2 = 7

New in version 2.3.3 (Firmware).

BrickIMU.setSPITFPBaudrate(brickletPort, baudrate[, returnCallback][, errorCallback])¶

Parameters:	brickletPort – Type: char, Range: ['a' to 'b'] baudrate – Type: int, Unit: 1 Bd, Range: [400000 to 2000000], Default: 1400000
Callback Parameters:	undefined
Returns:	undefined

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.

New in version 2.3.3 (Firmware).

BrickIMU.getSPITFPBaudrate(brickletPort[, returnCallback][, errorCallback])¶

Parameters:	brickletPort – Type: char, Range: ['a' to 'b']
Callback Parameters:	baudrate – Type: int, Unit: 1 Bd, Range: [400000 to 2000000], Default: 1400000
Returns:	undefined

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

New in version 2.3.3 (Firmware).

BrickIMU.getSPITFPErrorCount(brickletPort[, returnCallback][, errorCallback])¶

Parameters:	brickletPort – Type: char, Range: ['a' to 'b']
Callback Parameters:	errorCountACKChecksum – Type: int, Range: [0 to 2³² - 1] errorCountMessageChecksum – Type: int, Range: [0 to 2³² - 1] errorCountFrame – Type: int, Range: [0 to 2³² - 1] errorCountOverflow – Type: int, Range: [0 to 2³² - 1]
Returns:	undefined

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 2.3.3 (Firmware).

BrickIMU.enableStatusLED([returnCallback][, errorCallback])¶

Callback Parameters:	undefined
Returns:	undefined

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.

New in version 2.3.1 (Firmware).

BrickIMU.disableStatusLED([returnCallback][, errorCallback])¶

Callback Parameters:	undefined
Returns:	undefined

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.

New in version 2.3.1 (Firmware).

BrickIMU.isStatusLEDEnabled([returnCallback][, errorCallback])¶

Callback Parameters:	enabled – Type: boolean, Default: true
Returns:	undefined

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

New in version 2.3.1 (Firmware).

BrickIMU.getChipTemperature([returnCallback][, errorCallback])¶

Callback Parameters:	temperature – Type: int, Unit: 1/10 °C, Range: [-2¹⁵ to 2¹⁵ - 1]
Returns:	undefined

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.

BrickIMU.reset([returnCallback][, errorCallback])¶

Callback Parameters:	undefined
Returns:	undefined

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!

BrickIMU.getIdentity([returnCallback][, errorCallback])¶

Callback Parameters:

Callback Parameters:	uid – Type: string, Length: up to 8 connectedUid – Type: string, Length: up to 8 position – Type: char, Range: ['0' to '8'] hardwareVersion – 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] firmwareVersion – 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] deviceIdentifier – Type: int, Range: [0 to 2¹⁶ - 1]
Returns:	undefined

uid – Type: string, Length: up to 8
connectedUid – Type: string, Length: up to 8
position – Type: char, Range: ['0' to '8']
hardwareVersion – 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]

firmwareVersion – 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]

deviceIdentifier – Type: int, Range: [0 to 2¹⁶ - 1]

Returns:

undefined

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. There is also a constant for the device identifier of this Brick.

Callback Configuration Functions¶

BrickIMU.on(callback_id, function[, errorCallback])¶

Parameters:	callback_id – Type: int function – Type: function
Returns:	undefined

Registers the given function with the given callback_id.

The available callback IDs with corresponding function signatures are listed below.

BrickIMU.setAccelerationPeriod(period[, returnCallback][, errorCallback])¶

Parameters:	period – Type: int, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 0
Callback Parameters:	undefined
Returns:	undefined

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

BrickIMU.getAccelerationPeriod([returnCallback][, errorCallback])¶

Callback Parameters:	period – Type: int, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 0
Returns:	undefined

Returns the period as set by setAccelerationPeriod().

BrickIMU.setMagneticFieldPeriod(period[, returnCallback][, errorCallback])¶

Parameters:	period – Type: int, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 0
Callback Parameters:	undefined
Returns:	undefined

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

BrickIMU.getMagneticFieldPeriod([returnCallback][, errorCallback])¶

Callback Parameters:	period – Type: int, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 0
Returns:	undefined

Returns the period as set by setMagneticFieldPeriod().

BrickIMU.setAngularVelocityPeriod(period[, returnCallback][, errorCallback])¶

Parameters:	period – Type: int, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 0
Callback Parameters:	undefined
Returns:	undefined

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

BrickIMU.getAngularVelocityPeriod([returnCallback][, errorCallback])¶

Callback Parameters:	period – Type: int, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 0
Returns:	undefined

Returns the period as set by setAngularVelocityPeriod().

BrickIMU.setAllDataPeriod(period[, returnCallback][, errorCallback])¶

Parameters:	period – Type: int, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 0
Callback Parameters:	undefined
Returns:	undefined

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

BrickIMU.getAllDataPeriod([returnCallback][, errorCallback])¶

Callback Parameters:	period – Type: int, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 0
Returns:	undefined

Returns the period as set by setAllDataPeriod().

BrickIMU.setOrientationPeriod(period[, returnCallback][, errorCallback])¶

Parameters:	period – Type: int, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 0
Callback Parameters:	undefined
Returns:	undefined

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

BrickIMU.getOrientationPeriod([returnCallback][, errorCallback])¶

Callback Parameters:	period – Type: int, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 0
Returns:	undefined

Returns the period as set by setOrientationPeriod().

BrickIMU.setQuaternionPeriod(period[, returnCallback][, errorCallback])¶

Parameters:	period – Type: int, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 0
Callback Parameters:	undefined
Returns:	undefined

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

BrickIMU.getQuaternionPeriod([returnCallback][, errorCallback])¶

Callback Parameters:	period – Type: int, Unit: 1 ms, Range: [0 to 2³² - 1], Default: 0
Returns:	undefined

Returns the period as set by setQuaternionPeriod().

Callbacks¶

Callbacks can be registered to receive time critical or recurring data from the device. The registration is done with the on() function of the device object. The first parameter is the callback ID and the second parameter the callback function:

imu.on(BrickIMU.CALLBACK_EXAMPLE,
    function (param) {
        console.log(param);
    }
);

The available constants with inherent number and type of parameters are described below.

Note

Using callbacks for recurring events is always preferred compared to using getters. It will use less USB bandwidth and the latency will be a lot better, since there is no round trip time.

BrickIMU.CALLBACK_ACCELERATION¶

Callback Parameters:	x – Type: int, Unit: 1/1000 gₙ, Range: [-2¹⁵ to 2¹⁵ - 1] y – Type: int, Unit: 1/1000 gₙ, Range: [-2¹⁵ to 2¹⁵ - 1] z – Type: int, Unit: 1/1000 gₙ, Range: [-2¹⁵ to 2¹⁵ - 1]

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.

BrickIMU.CALLBACK_MAGNETIC_FIELD¶

Callback Parameters:	x – Type: int, Unit: 1/10 µT, Range: [-2¹⁵ to 2¹⁵ - 1] y – Type: int, Unit: 1/10 µT, Range: [-2¹⁵ to 2¹⁵ - 1] z – Type: int, Unit: 1/10 µT, Range: [-2¹⁵ to 2¹⁵ - 1]

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.

BrickIMU.CALLBACK_ANGULAR_VELOCITY¶

Callback Parameters:	x – Type: int, Unit: 8/115 °/s, Range: [-28750 to 28750] y – Type: int, Unit: 8/115 °/s, Range: [-28750 to 28750] z – Type: int, Unit: 8/115 °/s, Range: [-28750 to 28750]

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.

BrickIMU.CALLBACK_ALL_DATA¶

Callback Parameters:

accX – Type: int, Unit: 1/1000 gₙ, Range: [-2¹⁵ to 2¹⁵ - 1]
accY – Type: int, Unit: 1/1000 gₙ, Range: [-2¹⁵ to 2¹⁵ - 1]
accZ – Type: int, Unit: 1/1000 gₙ, Range: [-2¹⁵ to 2¹⁵ - 1]
magX – Type: int, Unit: 1/10 µT, Range: [-2¹⁵ to 2¹⁵ - 1]
magY – Type: int, Unit: 1/10 µT, Range: [-2¹⁵ to 2¹⁵ - 1]
magZ – Type: int, Unit: 1/10 µT, Range: [-2¹⁵ to 2¹⁵ - 1]
angX – Type: int, Unit: 8/115 °/s, Range: [-28750 to 28750]
angY – Type: int, Unit: 8/115 °/s, Range: [-28750 to 28750]
angZ – Type: int, Unit: 8/115 °/s, Range: [-28750 to 28750]
temperature – Type: int, Unit: 1/100 °C, Range: [-2¹⁵ to 2¹⁵ - 1]

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.

BrickIMU.CALLBACK_ORIENTATION¶

Callback Parameters:	roll – Type: int, Unit: 1/100 °, Range: [-18000 to 18000] pitch – Type: int, Unit: 1/100 °, Range: [-18000 to 18000] yaw – Type: int, Unit: 1/100 °, Range: [-18000 to 18000]

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.

BrickIMU.CALLBACK_QUATERNION¶

Callback Parameters:	x – Type: float, Range: [-1.0 to 1.0] y – Type: float, Range: [-1.0 to 1.0] z – Type: float, Range: [-1.0 to 1.0] w – Type: float, Range: [-1.0 to 1.0]

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.

Virtual Functions¶

Virtual functions don't communicate with the device itself, but operate only on the API bindings device object. They can be called without the corresponding IP Connection object being connected.

BrickIMU.getAPIVersion()¶

Returns:	apiVersion – 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]

Returns the version of the API definition 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.

BrickIMU.getResponseExpected(functionId[, errorCallback])¶

Parameters:	functionId – Type: int, Range: See constants
Returns:	responseExpected – Type: boolean

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.

The following constants are available for this function:

For function_id:

BrickIMU.FUNCTION_LEDS_ON = 8
BrickIMU.FUNCTION_LEDS_OFF = 9
BrickIMU.FUNCTION_SET_ACCELERATION_RANGE = 11
BrickIMU.FUNCTION_SET_MAGNETOMETER_RANGE = 13
BrickIMU.FUNCTION_SET_CONVERGENCE_SPEED = 15
BrickIMU.FUNCTION_SET_CALIBRATION = 17
BrickIMU.FUNCTION_SET_ACCELERATION_PERIOD = 19
BrickIMU.FUNCTION_SET_MAGNETIC_FIELD_PERIOD = 21
BrickIMU.FUNCTION_SET_ANGULAR_VELOCITY_PERIOD = 23
BrickIMU.FUNCTION_SET_ALL_DATA_PERIOD = 25
BrickIMU.FUNCTION_SET_ORIENTATION_PERIOD = 27
BrickIMU.FUNCTION_SET_QUATERNION_PERIOD = 29
BrickIMU.FUNCTION_ORIENTATION_CALCULATION_ON = 37
BrickIMU.FUNCTION_ORIENTATION_CALCULATION_OFF = 38
BrickIMU.FUNCTION_SET_SPITFP_BAUDRATE_CONFIG = 231
BrickIMU.FUNCTION_SET_SPITFP_BAUDRATE = 234
BrickIMU.FUNCTION_ENABLE_STATUS_LED = 238
BrickIMU.FUNCTION_DISABLE_STATUS_LED = 239
BrickIMU.FUNCTION_RESET = 243
BrickIMU.FUNCTION_WRITE_BRICKLET_PLUGIN = 246

BrickIMU.setResponseExpected(functionId, responseExpected[, errorCallback])¶

Parameters:	functionId – Type: int, Range: See constants responseExpected – Type: boolean
Returns:	undefined

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.

The following constants are available for this function:

For function_id:

BrickIMU.FUNCTION_LEDS_ON = 8
BrickIMU.FUNCTION_LEDS_OFF = 9
BrickIMU.FUNCTION_SET_ACCELERATION_RANGE = 11
BrickIMU.FUNCTION_SET_MAGNETOMETER_RANGE = 13
BrickIMU.FUNCTION_SET_CONVERGENCE_SPEED = 15
BrickIMU.FUNCTION_SET_CALIBRATION = 17
BrickIMU.FUNCTION_SET_ACCELERATION_PERIOD = 19
BrickIMU.FUNCTION_SET_MAGNETIC_FIELD_PERIOD = 21
BrickIMU.FUNCTION_SET_ANGULAR_VELOCITY_PERIOD = 23
BrickIMU.FUNCTION_SET_ALL_DATA_PERIOD = 25
BrickIMU.FUNCTION_SET_ORIENTATION_PERIOD = 27
BrickIMU.FUNCTION_SET_QUATERNION_PERIOD = 29
BrickIMU.FUNCTION_ORIENTATION_CALCULATION_ON = 37
BrickIMU.FUNCTION_ORIENTATION_CALCULATION_OFF = 38
BrickIMU.FUNCTION_SET_SPITFP_BAUDRATE_CONFIG = 231
BrickIMU.FUNCTION_SET_SPITFP_BAUDRATE = 234
BrickIMU.FUNCTION_ENABLE_STATUS_LED = 238
BrickIMU.FUNCTION_DISABLE_STATUS_LED = 239
BrickIMU.FUNCTION_RESET = 243
BrickIMU.FUNCTION_WRITE_BRICKLET_PLUGIN = 246

BrickIMU.setResponseExpectedAll(responseExpected)¶

Parameters:	responseExpected – Type: boolean
Returns:	undefined

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

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.

BrickIMU.getProtocol1BrickletName(port[, returnCallback][, errorCallback])¶

Parameters:	port – Type: char, Range: ['a' to 'b']
Callback Parameters:	protocolVersion – Type: int, Range: [0 to 255] firmwareVersion – 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:	undefined

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.

BrickIMU.writeBrickletPlugin(port, offset, chunk[, returnCallback][, errorCallback])¶

Parameters:	port – Type: char, Range: ['a' to 'b'] offset – Type: int, Range: [0 to 255] chunk – Type: [int, ...], Length: 32, Range: [0 to 255]
Callback Parameters:	undefined
Returns:	undefined

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.

BrickIMU.readBrickletPlugin(port, offset[, returnCallback][, errorCallback])¶

Parameters:	port – Type: char, Range: ['a' to 'b'] offset – Type: int, Range: [0 to 255]
Callback Parameters:	chunk – Type: [int, ...], Length: 32, Range: [0 to 255]
Returns:	undefined

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.

Constants¶

BrickIMU.DEVICE_IDENTIFIER¶

This constant is used to identify a IMU Brick.

The getIdentity() function and the IPConnection.CALLBACK_ENUMERATE callback of the IP Connection have a device_identifier parameter to specify the Brick's or Bricklet's type.

BrickIMU.DEVICE_DISPLAY_NAME¶: This constant represents the human readable name of a IMU Brick.