How to get calibration values for my accelerometer

Hello all, I'm building my own flight controller and I'm using the mpu9250 IMU.

I'm sampelling the data at 1[khz].

I wasn't able to find if there is a function or app in Matlab that I can use to get the desigred bias and magnitude calibration values for my accelerometer.

I want to record the data from my IMU and than use it in some Matlab function to get the calibration values :)

Thank you for the help!

[Walter Roberson]

https://www.mathworks.com/help/supportpkg/beagleboneblue/ref/calibrateaccel.html

https://www.mathworks.com/matlabcentral/answers/488885-mpu9250-calibration-with-simulink-by-matlab-function#answer_867475

https://www.mathworks.com/help/fusion/ug/Estimating-Orientation-Using-Inertial-Sensor-Fusion-and-MPU-9250.html

Answer 1

[Bora Eryilmaz]

It looks like this IC has a 16-bit ADC. Depending on which acceleration range you select, the magnitude would be scaled as:

range = 2; % For a full-scale range of +/-2g.
magADC = 4096; % A 16-bit value read from the accelerometer.
magG = (magADC / 2^16) * range % Magnitude in g.

magG = 0.1250

The bias correction would require reading a steady +1g from the accelerometer when it is at rest and adjusting the magADC value above as:

magADC0 = 35000; % Say you read this value for +1g, instead of the theoretical 32768.
delta = magADC0 - 2^15; % This is the bias correction needed.
magG = (magADC0 / 2^16) * range % This would be the uncalibrated value.

magG = 1.0681

magADC = 35000; % The values you would read later during operation.
magG = (magADC - delta) / 2^16 * range % This is the calibrated value.

magG = 1