I have ADXL345 digital accelerometer by Analog Devices. I use Beaglebone ADXL345 library that exist here: http://inspire.logicsupply.com/2014/08/beaglebone-3-axis-accelerometer.html
So I can read the accelerations at X,Y,Z axis. However, when I placed the board at plate surface, it reads X and Y accelerations as -0.728G and -0.788G. They should be zero. How to calibrate this accelerometer?
In addition, it reads stable z axis accelaration as 2.044G. It only changes If I reverse the board. I dont understand. What does it mean?
my ADXL345 board: