Readings lag

[caternuson]

Issue can be seen by running bno08x_rvc_simpletest.py example and observing output while moving the sensor.

Start with board flat so Z axis is point up:

Yaw: 1.67 Pitch: -2.07 Roll: 1.29 Degrees
Acceleration X: -0.24 Y: -0.34 Z: 9.58 m/s^2

Yaw: 1.67 Pitch: -2.07 Roll: 1.29 Degrees
Acceleration X: -0.20 Y: -0.34 Z: 9.58 m/s^2

Yaw: 1.67 Pitch: -2.06 Roll: 1.29 Degrees
Acceleration X: -0.20 Y: -0.34 Z: 9.58 m/s^2

Looks good. Now move board 90 degrees so Z axis is horizontal:

Yaw: 1.69 Pitch: -2.06 Roll: 1.30 Degrees
Acceleration X: -0.24 Y: -0.34 Z: 9.58 m/s^2

Yaw: 1.69 Pitch: -2.06 Roll: 1.30 Degrees
Acceleration X: -0.24 Y: -0.38 Z: 9.54 m/s^2

Yaw: 1.69 Pitch: -2.06 Roll: 1.30 Degrees
Acceleration X: -0.20 Y: -0.34 Z: 9.54 m/s^2

No changes. But then wait many 10's of seconds and readings finally change:

Yaw: -171.00 Pitch: -87.48 Roll: 164.32 Degrees
Acceleration X: -0.16 Y: -9.93 Z: -0.42 m/s^2

Yaw: -171.00 Pitch: -87.48 Roll: 164.32 Degrees
Acceleration X: -0.12 Y: -9.93 Z: -0.42 m/s^2

Yaw: -171.00 Pitch: -87.48 Roll: 164.32 Degrees
Acceleration X: -0.12 Y: -9.93 Z: -0.42 m/s^2

This is most likely due to a UART buffer. The BNO080 in RVC mode is constantly spamming data over UART. So new readings won't show up until enough calls are made to read the heading property to clear out buffered data containing old readings.

Forum thread for reference:
https://forums.adafruit.com/viewtopic.php?t=215071

[caternuson]

Closing. Fixed with #9.