MultiWii

Running multiwii on a Arduino Nano.
Using the MPU6050 gyro/acc
On the white graph in MultiWiiConf I see the blue line which is the Z axis not in the zero position. It’s in its top position. The 2 other lines are in the zero position.
When I rotate the board on which the MPU6050 is mounted 90 degrees counter clockwise the
Blue line goes to the zero position.
The horizon indicator on the top rightmost position moves from its flat (normal) position to the -90 degrees position.

My question is if this is normal behavior?

Z axis should detect 1G some how and it would put a negative number when held inverted
on my board its 500+ upright and when held upside down its 500-

also given my board is mounted upright flat otherwise if you have some weird orientation configured in the config.h

gyro and acc must be calibrated before usage. This can be done via receiver input or via gui.