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Sensor Fusion & Battery duration

UpgradingUpgrading
in Firmware

Hi,
we are working on two MetaMotionC devices, fw 1.3.7, and we're acquiring Linear Acceleration data through Sensor Fusion in order to track human movements. We have several questions:
1. is it possible to stream both euler angles and linear acceleration? We need to evaluate acceleration direction by north direction
2. in this scenario (euler angles + linear acceleration), assuming we're also reading RSSI data, using data streaming and not logging, what battery duration do you expect? We need to acquire data each 10 seconds
3. during data acquisition it seems to be a lack of precision due to continue recalibration (you can see a step in the graph on the y axis). This behavour avoid us to evaluate, for example, the correct distance traveled by the person. Do you expect this behaviour?

Comments

  • EricEric
    1. Yes
    2. I can't really give you an answer other than you need to test this yourself. Run some battery tests and if they aren't what you need, then provide more details about your use case and we can try to provide some suggestions for extending up time.
    3. When did that step occur? Did it happen while the board was laying still? Did it spike when the person started moving? Did you calibrate the boards before hand?
  • UpgradingUpgrading
    1. OK
    2. We are doing an Indoor tracking system, by checking mote orientation, acceleration and distance from a smartphone. After few tests we see that battery has approximatly 16/20 hours of life.
    3. The entire graph refers to a typical situation: the board is laying still (first 2 seconds), then there is a spike when the person started moving, and the person stops at 7.5s, no other actions we took after 7.5s
  • EricEric
    edited July 2018
    • Does 16-20 hours fit your operational parameters?
    • Again, did you calibrate the boards (sensor fusion algorithm) before starting the tests?
  • UpgradingUpgrading

    Our desiderated duration is 6 months at least..
    We didn't calibrate anything. We saw a new "Calibration section" in the SDK docs: https://mbientlab.com/androiddocs/latest/sensor_fusion.html
    The "Bosch tutorial video (Youtube)" for calibration has a wrong link, can you give me the right link please?

  • EricEric
    edited July 2018

    You're not going to get 6 months on one battery running the sensor fusion algorithm. You can try the other sensor fusion modes that sample the sensors at lower frequencies but those do not use the gyro.

    Here's the corrected link:
    https://www.youtube.com/watch?v=Bw0WuAyGsnY

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