### Q

Could you tell me if it is possible to calibrate the ADXL345?

### A

Calibration is done similar to any other accelerometer. Depending on howcalibrated you would like it to be. Basically, you would just place the part

flat, so 1 g in Z, 0 g in X and Y, determine the offset and then program the

opposite value into the OFFSET registers of the part. This would need to be

reprogrammed whenever the part is power-cycled though. If you want it to be

even more calibrated, you should also orient it such that there is a 0 g in the

Z-axis, to correctly calibrate the 0 g offset of Z, otherwise you assume an

ideal 256 codes and calibrate for that.

Sensitivity can be calibrated the same way. Position the sensor such that 1 g

is in the positive direction, say +X, record how many LSBs that is, then rotate

it so that 1 g is in the -X and record that. Half of the average value would

be the offset and half the sum of the absolute value of each would be the

sensitivity. i.e.

If +X was +270 LSB and -X was -250 LSB:

+270 + (-250) = +20 LSB

Offset would be +10 LSB