Manual calibration of the IMU is definitely NOT necessary: except for the magnetometer * (which is not used by the default {@link BNO055IMU.SensorMode#IMU * SensorMode#IMU}), the BNO055 is internally self-calibrating and thus can be very successfully * used without manual intervention. That said, performing a one-time calibration, saving the * results persistently, then loading them again at each run can help reduce the time that automatic * calibration requires.
* *This summary of the calibration process, from * Intel, is informative:
* *"This device requires calibration in order to operate accurately. [...] Calibration data is * lost on a power cycle. See one of the examples for a description of how to calibrate the device, * but in essence:
* *There is a calibration status register available [...] that returns the calibration status * of the accelerometer (ACC), magnetometer (MAG), gyroscope (GYR), and overall system (SYS). * Each of these values range from 0 (uncalibrated) to 3 (fully calibrated). Calibration [ideally] * involves certain motions to get all 4 values at 3. The motions are as follows (though see the * datasheet for more information):
* *To calibrate the IMU, run this sample opmode with a gamepad attached to the driver station. * Once the IMU has reached sufficient calibration as reported on telemetry, press the 'A' * button on the gamepad to write the calibration to a file. That file can then be indicated * later when running an opmode which uses the IMU.
* *Note: if your intended uses of the IMU do not include use of all its sensors (for exmaple, * you might not use the magnetometer), then it makes little sense for you to wait for full * calibration of the sensors you are not using before saving the calibration data. Indeed, * it appears that in a SensorMode that doesn't use the magnetometer (for example), the * magnetometer cannot actually be calibrated.
* * @see AdafruitBNO055IMU * @see BNO055IMU.Parameters#calibrationDataFile * @see BNO055 product page * @see BNO055 specification */ @TeleOp(name = "Sensor: BNO055 IMU Calibration", group = "Sensor") @Disabled // Uncomment this to add to the opmode list public class SensorBNO055IMUCalibration extends LinearOpMode { //---------------------------------------------------------------------------------------------- // State //---------------------------------------------------------------------------------------------- // Our sensors, motors, and other devices go here, along with other long term state BNO055IMU imu; // State used for updating telemetry Orientation angles; //---------------------------------------------------------------------------------------------- // Main logic //---------------------------------------------------------------------------------------------- @Override public void runOpMode() { telemetry.log().setCapacity(12); telemetry.log().add(""); telemetry.log().add("Please refer to the calibration instructions"); telemetry.log().add("contained in the Adafruit IMU calibration"); telemetry.log().add("sample opmode."); telemetry.log().add(""); telemetry.log().add("When sufficient calibration has been reached,"); telemetry.log().add("press the 'A' button to write the current"); telemetry.log().add("calibration data to a file."); telemetry.log().add(""); // We are expecting the IMU to be attached to an I2C port on a Core Device Interface Module and named "imu". BNO055IMU.Parameters parameters = new BNO055IMU.Parameters(); parameters.loggingEnabled = true; parameters.loggingTag = "IMU"; imu = hardwareMap.get(BNO055IMU.class, "imu"); imu.initialize(parameters); composeTelemetry(); telemetry.log().add("Waiting for start..."); // Wait until we're told to go while (!isStarted()) { telemetry.update(); idle(); } telemetry.log().add("...started..."); while (opModeIsActive()) { if (gamepad1.a) { // Get the calibration data BNO055IMU.CalibrationData calibrationData = imu.readCalibrationData(); // Save the calibration data to a file. You can choose whatever file // name you wish here, but you'll want to indicate the same file name // when you initialize the IMU in an opmode in which it is used. If you // have more than one IMU on your robot, you'll of course want to use // different configuration file names for each. String filename = "AdafruitIMUCalibration.json"; File file = AppUtil.getInstance().getSettingsFile(filename); ReadWriteFile.writeFile(file, calibrationData.serialize()); telemetry.log().add("saved to '%s'", filename); // Wait for the button to be released while (gamepad1.a) { telemetry.update(); idle(); } } telemetry.update(); } } void composeTelemetry() { // At the beginning of each telemetry update, grab a bunch of data // from the IMU that we will then display in separate lines. telemetry.addAction(new Runnable() { @Override public void run() { // Acquiring the angles is relatively expensive; we don't want // to do that in each of the three items that need that info, as that's // three times the necessary expense. angles = imu.getAngularOrientation(AxesReference.INTRINSIC, AxesOrder.ZYX, AngleUnit.DEGREES); } }); telemetry.addLine() .addData("status", new Func