Metamotion r IMU calibration

Comments

• Eric

  January 2017

  Are you restarting and/or reconfiguring the sensor fusion algorithm upon connecting?  What is the code being executed prior to closing the app and after connecting to the board?
• paner

  January 2017

  When i am connection i am running 

  
  

  public void sample(boolean isChecked) throws Exception {
      if (isChecked) {
          isStopped = false;
          // stream quaternion values from the board
          fusionModule.routeData().fromQuaternions().stream("quaternion").commit()
                  .onComplete(new AsyncOperation.CompletionHandler<RouteManager>() {
                      @Override
                      public void success(RouteManager result) {
                          result.subscribe("quaternion", new RouteManager.MessageHandler() {
                              @Override
                              public void process(Message msg) {
                                  //Log.i("example", msg.getData(SensorFusion.Quaternion.class).toString());
                                  SensorFusion.Quaternion quaternion = msg.getData(SensorFusion.Quaternion.class);
                                  for (IFusionSubscriber subscriber : subscribers) {
                                      try {
                                          subscriber.notified(quaternion);
                                      } catch (Exception ex) {
                                          logger.error("An error occurred", ex);
                                      }
  
                                  }
  
                              }
                          });
                          fusionModule.start(SensorFusion.DataOutput.QUATERNION);
                      }
                  });
      } else {
          try {
              fusionModule.stop();
          } catch(Exception ex) {
              ex.printStackTrace();
          }
  
          isStopped = true;
      }
  
  }

  Is the board caching a starting point from the first run until reset?
• Eric

  January 2017

  The sensor fusion algorithm resets its internal state when you change configuration or start the algorithm.  Are you configuring the algorithm elsewhere (don't see code to set mode to IMUPlus) and stopping the algorithm before closing the app?

  
  

  
  

  
  
• paner

  January 2017

  In the same Class with the above code i have his:

  
  

  public static FusionWrapper getInstance(MetaWearBoard.Module board) throws Exception {
      if (null == board) {
          logger.error("An error occured", "Null passed for board in FusionWrapper");
          throw new Exception("Null passed for board");
      }
      fusionModule = (SensorFusion) board;
      fusionModule.configure()
              .setMode(SensorFusion.Mode.IMU_PLUS)
              .setAccRange(SensorFusion.AccRange.AR_16G)
              .commit();
      if (null == instance) {
          instance = new FusionWrapper();
      }
      return instance;
  }

  And in my activity i have this to initialize the fusion:

  @Override
  public void onServiceConnected(ComponentName name, IBinder service) {
      // Typecast the binder to the service's LocalBinder class
      mwBoard = ((MetaWearBleService.LocalBinder) service).getMetaWearBoard(device);
      mwBoard.setConnectionStateHandler(connectionHandler);
      if (mwBoard == null || !mwBoard.isConnected()) {
          accel_switch.setEnabled(false);
      } else {
          accel_switch.setEnabled(true);
          try {
              fusionWrapper = FusionWrapper.getInstance(mwBoard.getModule(SensorFusion.class));
          } catch (Exception ex) {
              logger.error("An Error Occurred", ex);
          }
      }
      invalidateOptionsMenu();
  
  }

  When a menu item is pressed i close the algorithm like this:

  case R.id.disconnect_menu:
      if (accel_switch.isChecked()) {
          accel_switch.setChecked(false);
      } else {
          if (fusionWrapper.isStopped()) {
              mwBoard.setConnectionStateHandler(null);
              mwBoard.disconnect();
              accel_switch.setEnabled(false);
              invalidateOptionsMenu();
          }
  
      }
      return true;

  My problem is when i start the algorithm it has a predefined starting location 

  but if i reset the board from the menu when i first run the algorithm it takes

  the current board location as starting and then calculates the orientation from there and this is what i want.

  If i close the application run it again and whatever i do except the reset the predifined location stays the same.

  Also Metawear r has a button to start and close? because the battery is always connected. To open it i have to connect it with a pc and then stays opened.

  Thank you,

  Jim
• Eric

  January 2017

  After doing some testing and talking with the firmware dev, you will have to reset the board to reset the position.

  
  

  The board is always powered on when a power source is attached.
• paner

  January 2017

  Thank you for the info, one last question:
  
  If i connect the board in my pc with a cable and then disconnect it how much time the board says open without connecting to it?
  

  
  

  Thanks,

  Jim
• Eric

  January 2017

  I'm not sure what you mean by "stays open without connecting to it".  Assuming you mean how long the battery lasts, that depends on the use case.  The board can advertise as an iBeacon or measure temperature every 30 minutes for months but running motion sensors (acc, gyro, mag) will drain the battery in days.