quaternion output is broken

[jarekdudzinski]

Hey. There is something very wrong with quaternion output... When I set filter to NONE - all axes are correct, but there is strong drift as magnetometer is not integrated. Using MADGWICK or MAHONY - X and Z axes are reversed, Y is correct.

Any solution to this? I need the quaternion output, as most of 3D apps are using it (converted to rotation matrices), and also it doesn't generate gimbal lock problem.

EDIT: probably the problem lies in the filters, not the quaternion itself - as the not filtered output is ok. Isn't it connected to some changes in filters and different orientation axes?

[jarekdudzinski]

PS: how I'm interpreting quaternions

1. sending values through serial to PC

2. on PC side, I'm using Processing script, attaching Quaternion class with method of conversion to transoformation matrix:

   class Quaternion {
   float x = 0.0; float y = 0.0; float z = 0.0;
   float w = 1.0;
   
   Quaternion() { }
   
   Quaternion(float x, float y, float z, float w) {
   this.x = x; this.y = y; this.z = z; this.w = w;
   }
   
   Quaternion(Quaternion q) {
   x = q.x; y = q.y; z = q.z; w = q.w;
   }
   PMatrix3D toMatrix() {
   return toMatrix(new PMatrix3D());
   }
   
   PMatrix3D toMatrix(PMatrix3D out) {
   float x2 = x + x; float y2 = y + y; float z2 = z + z;
   float xsq2 = x * x2; float ysq2 = y * y2; float zsq2 = z * z2;
   float xy2 = x * y2; float xz2 = x * z2; float yz2 = y * z2;
   float wx2 = w * x2; float wy2 = w * y2; float wz2 = w * z2;
   out.set(
     1.0 - (ysq2 + zsq2), xy2 - wz2, xz2 + wy2, 0.0,
     xy2 + wz2, 1.0 - (xsq2 + zsq2), yz2 - wx2, 0.0,
     xz2 - wy2, yz2 + wx2, 1.0 - (xsq2 + ysq2), 0.0,
     0.0, 0.0, 0.0, 1.0);
   return out;
   }
   }

[hideakitai]

@jarekdudzinski This issue will be fixed by https://github.com/hideakitai/MPU9250/tree/bugfix_obromious. Please confirm if it works.

[hideakitai]

Fixed in v0.4.3. Please reopen the issue if you still have the problem.