[Dprglist] Compass heading using gyroscopes?

[Doug Paradis]

Murray,
   I think it also depends on the degree of accuracy you want. If you want
your compass to tell you N,NE,E,SE,S,SW,W,NW 'ish, you calibration doesn't
need to be as complete as if you want +/- 0.1 degree.

Regards,
Doug P>

On Thu, May 14, 2020 at 11:33 PM Murray Altheim <murray18 at altheim.com>
wrote:

> Hi Doug,
>
> Thanks for the clarification. If I want a magnetometer in the mix I've
> got to wave my robot or my motorcycle in the air, understood. I think
> I now better understood why you might like the IMU mode, which, not
> including the magnetometer, doesn't require all that waving around
> business. If I can get away with that it does sound preferable.
>
> In any case, this sounds like I should do a bit more experimentation
> with the various BNO055 modes before making a decision on which sensor
> to use, and stop blaming the BNO055 for having some kind of specialised
> calibration. That's kinda what I'd gathered but it's good to have that
> confirmed, thanks!
>
> Cheers,
>
> Murray
>
> On 15/05/20 4:17 pm, Doug Paradis wrote:
> > Murray,
> > The "fusion" of the sensors is the Kalman filter (or the secret
> > sauce). The difference between imu and ndof modes is that the
> > magnetometer is added to the gyroscope and accelerometer sensors.
> > It is the magnetometer that needs to be waved in the air. The
> > gyroscope and accelerometer will self-calibrate after a short
> > period of time. To calibrate any magnetometer, you have to wave
> > it a bit (for example an iphone). The big advantage of the BNO055
> > is the low drift of the gyroscope (due in part to the internal
> > Kalman filter).
> ...........................................................................
> Murray Altheim <murray18 at altheim dot com>                       = =  ===
> http://www.altheim.com/murray/                                     ===
> ===
>                                                                     = =
> ===
>      In the evening
>      The rice leaves in the garden
>      Rustle in the autumn wind
>      That blows through my reed hut.
>             -- Minamoto no Tsunenobu
>
>
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