Originally Posted by AndyOne
OK in a nutshell, here's what I learnt the hard way.
1 Most importantly, the sensor board MUST be located component side up and not as in the magnetometer cal screen.
2 On the GIU screen click on "show" menu and select advanced settings. in the top right hand corner some adjustment of the "gyro weight on pan %" may be necessary, 99% seems best.
3 In the accelerometer cal screen click on "help" menu and select help/how to, to see exactly how to position the sensor for calibration.
4 Regular resetting of the Arduino by pressing the on-board reset button seems to help
5 Select disconnect when exiting a calibration screen to release the serial link so it can be used by another cal screen.
Always good to know to obvious things I haven't documented good enough... Documenting is not really my strong side.
Reset shouldn't be necessary - at least quite a few people have been able to make it work pretty good without drift.
Anyway, if you ever need to reset center, it's a lot better to connect a button between to be used as "set center".
The pin is defined in config:
// Button input:
#define BUTTON_INPUT 11
Just connect a button between the pin defined (in this case 11)) and ground. Will make it center immediately with no start-up delay