Value accelerometer

good morning everyone

When I install my Cube Orange always caliber the accelerometers at the work desk when it is not yet mounted on the frame

I ask about these 2 questions:

  1. In case of upgrades or downgrade I always have to calibrate the accelerometers or the values remain intact?

  2. What is the instruction to verify the value of the accelerometers? In this case I could personally check if the values were deleted or not (and return to question 1)

thank you

Hello Frank,

  1. No, updates in the firmware of your ardupilot shouldn’t touch the calibration parameters, unless you are changing from one kind of vehicle to another (like changing from Arducopter to Arduplane);
  2. I do not think this way of calibrating on a desk is recommendable, you can have misalignments in your drone that are not reflected in your desk. You should at least perform the level calibration. If I am not mistaken, now MP supports a special accel calibration for large drones, but I have never used it.

Hi Bruno and thanks for your kind reply… … The problem is precisely that of dimensions. I use a self-built 1.1 meter wheelbase and go from cube black to Orange and therefore I have to organize myself for calibration and since the dimensions are not exactly “insignificant”, I have the problem of encumbrance. I did not know the auto calibration procedure for large objects (like the “in flight” calibration of the compass… procedure that I always use). As a rule, I gauge the axes (occasionally) with the FCU at the bench, reserving the right to execute only the “Level” when it is on the machine … … one more quick info … … what is the set of parameters where I can read the values ​​acquired by the accelerometers? I need to know this to understand, in case of an upgrade (of the same model of course) if they have been touched / modified or not…. anyway thanks for the info

Hi Frank,

As it is available now in MP, you should try this accel calibration for large vehicles.

I think the parameters of your interest are the INS_ACCNSCAL_ and INS_ACCNOFFS_, whre ACCN is the number of your accelerometer (ACC1, ACC2 etc.). I understand your worries about it, but I think that if the values go back to default, it will activate the Pre-Arm Check of uncalibrated accelerometers.

But, as a general rule, it is always a good practice to save your parameters list into a file before any SW update. This way, you can proceed with the update and after that compare the current parameters with the old list, so you can track if something changed unexpectedly and/or if there is any new parameter that you should configure properly.