Did not receive data processor id within 250ms Exception

Comments

• Eric

  July 2019

  What do you do when you disconnect from the sensors or are done sampling data?
• gregorij

  July 2019 edited July 2019

  When done logging data, the following code would be called (few non-sensor related lines removed):

      public async Task StopLoggingAsync()
      {
      var sensorFusion = _metawear.GetModule<ISensorFusionBosch>();
              sensorFusion.LinearAcceleration.Stop();
              sensorFusion.Quaternion.Stop();
  
              var logging = _metawear.GetModule<ILogging>();
              logging.Stop();
              await Task.Delay(500);
  
              _metawear.GetModule<ISettings>().EditBleConnParams(maxConnInterval: 12.5f);
              await Task.Delay(3000);
  
              int errorCount = 0;
              await logging.DownloadAsync(100,
                  (n1, n2) =>
                  {
                          /// Copy to data vector ...
                  }
                   ,
                   (lde, b, dt, ba) =>
                   {
                       errorCount++;
                       System.Diagnostics.Debug.WriteLine("lde: {0}, b: {1}, dt: {2}, ba:{3}, total err: {4}", lde, b, dt, ba, errorCount);
                   }
                   );
          }
          catch (Exception ex)
          {
              // log exception
          }
      }
  

  Disconnect would happen separately as there may be multiple sequences recorded (and downloaded) within a connected session. If the sensors created the routes without this exception, then multiple recordings work just fine. In general, this would be the disconnect process.

  public async Task DisconnectAsync()
      {
          var logging = _metawear.GetModule<ILogging>();
          if (logging != null)
          {
              logging.ClearEntries();
          }
  
          if (!_metawear.InMetaBootMode && _metawear.IsConnected)
          {
              /// turn LEDs off...
  
              // Disconnect
              var module = _metawear.GetModule<IDebug>();
              if (module != null)
                     await module.DisconnectAsync();
          }
          return task;
      }
  
• Eric

  July 2019

  You need to clean up board resources.

  https://mbientlab.com/csdocs/1/metawearboard.html#tear-down
• gregorij

  August 2019

  Eric, thanks for the replies. I actually did have a teardown included, just forgot to paste it into the code.

  It turned out the issue was related to something else. In my app, the user can connect and disconnect to sensors within the same app life cycle. I wrote a custom device scanner that connects to pre-configured devices. I use MbientLab.MetaWear.Win10.Application.GetMetaWearBoard() to get the device and MbientLab.MetaWear.Win10.Application.RemoveMetaWearBoard() to remove. I did not realize though that I needed to set the 'dispose' flag to true in order to properly clean up. Apparently I still got to the device the next time around calling GetMetaWearBoard(), but initialization or another method would fail with the timeout exception. Adding the dispose flag fixed the issue. The tutorial examples don't seem to demonstrate the use RemoveMetaWearBoard()...