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Sensor + Data

bhargavbhargav
in General

Hello, Guten Tag!

I am using a MMR.

  1. How to turn off the sensor? I see when i connect it blinks green. But how to disconnect? It happens that i close my app and still the sensor blinks red. and if I reopen my app and the sensor is connected.

  2. I went through the tutorials and read the datasheet, Could not find the range of the bluetooth. Could you please tell me what the range is of the bluetooth? In my application, I am tracking an object moving in a packaging machine of length 55 meters. Plus. The sensor is inside the object and I want to waterproof it using Resin, Will it be a problem?

  3. How exactly it records data ? It records data only when you are connected in metabase app ?

  4. I am particularly interested in using gyroscope, Euler angles, Accelerometer. I see Error in all three datas. But the error is constant after a while. For example, Sensor fusion Euler angle has pitch-4.98, Roll- -1.52, Yaw- 0.03. This are the reading after 2 seconds or so. The sensor is still. The same thing happens with gyroscope and accelerometer just that it has a range.
    Is it normal? Do I need to do calibration?

Accelerometer X- -0.010 to -0.020 Y- - 0.07 to 0.09 Z- 1.01 to 1.02

Thank you very much. Have a nice day

Comments

  • LauraLaura
    1. There is an API function to disconnect and an API function to turn off the sensor, please see www.mbientlab.com/tutorials to learn how to use them. In the MetaBase App, there is also a menu option to turn off the sensor.
    2. Bluetooth is standard, the range is around 30ft. You can google this or go to the Bluetooth SIG page for the full Bluetooth spec.
    3. No, you can stream OR log data.
    4. This might be drift, make sure the right mode is turned on.
  • bhargavbhargav
    edited August 2020

    Thank you very much for your quick response as always.

    1. Let me rephrase my question. What happens if I am in logging mode and the Sensor carrier is out of the range with the device connected. (Bluetooth is no longer in the range) . Will it keep recording?

    I have experimented something like that. I recorded data for a minute and then I turn off the Bluetooth of android device and then again turned on after 30 seconds to see what happens. I did not get any data at all.

    So what happens? Will it keep recording even if it is not in the range. Or it will again start recording when it comes in the range of android device.

    1. I am attaching all three readings. Could you please tell me what are these errors? Constant Bias? Is it normal or I need to do calibration. If it is constant Bias then I will just subtract the errors from the readings.

    The sensor is still.

    Thank you . Have a nice day.!



  • LauraLaura
    1. No it will no keep recording. You need to set it to the log mode before you disconnect if you want that to happen.
    2. The data you show actually looks really good and is exactly what real world data looks like.
  • bhargavbhargav
    edited August 2020

    Again Thank you very much.

    1. Should not be the accelerometer reading in y zero, ay = 0? And in Euler angle roll and pitch zero? It is constant so I can subtract it from all the values but I am trying to understand your answer. You said it is how the real world data should look like meaning This much error is normal or these are not errors and in fact these are the actual data
  • LauraLaura

    https://mbientlab.com/tutorials/Orientation.html

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