Openbci_gui: Accelerometer axes

[jps2000]

Problem

Accelerometer report x, y, z axes. Rotating the Ganglion revealed that the sign of axes are not right hand cartesian coordinates ( Turning +x into +y axis should point in +z direction (right hand screw)

Expected

Right hand coordinate repersentation
Hence z should change sign or x exchanged with y

Operating System and Version

Windows 7 professional 64bit

GUI Version

4.0.2 ( probably in all versions)

Type of OpenBCI Board

Ganglion

Are you using a WiFi Shield?

No

[jps2000]

Note that acc chip has changed pcb side between cyton and ganglion. ( hence x and z axis changed sign, y remains)
Preferably ganglion should deliver same axes as cyton. This should be taken into account in ganglion stack not in GUI as it has to do with hardware.

[retiutut]

Note that acc chip has changed pcb side between cyton and ganglion. 👍

The following pictures document this issue. Cyton and Ganglion were placed side by side using GUI on two machines, then rotated in the same way. The GUI shows different results:

• Flat and facing up
  
  

• Rotation 1
  
  

• Rotation 2
  
  

[jps2000]

Yeah thats what I discovered.
Assuming Cyton as the reference, Ganglion should deliver same acc output (preferably).

[retiutut]

@andrewjaykeller Can I go ahead and fix this in the Accelerometer widget using _Cyton as a reference_?

[andrewjaykeller]

So X and Z are multipled by -1?

[retiutut]

So X and Z are multiples by -1?

Z can be inverted for Ganglion.

X and Y may need to be swapped?

[jps2000]

Considering Cyton as reference:
In displaying Ganglion , Z need to be inverted AND X and Y need to be swapped but do not change sign.

[jps2000]

Solved in 4.1.0
Thank you