Question

Which of the formulae give us the value of acceleration for the x-axis in the ADXL-335?

(a) Axout = (((Value * Vref) / 1024) – 1.65) / 0.330

(b) Axout = (((Value * Vref) / 1024) – 1.65) / 2000

(c) Axout = (((Value * Vref) / 1024) – 1.65) / 330

(d) Axout = (((Value * Vref) / 1024) – 1.65) / 0.12

I have been asked this question during an internship interview.

The doubt is from ADXL335 Accelerometer Sensor in section Interfacing of Sensors, Actuators, and Other Modules of Arduino

Answer 1

Right choice is (a) Axout = (((Value * Vref) / 1024) – 1.65) / 0.330

To explain I would say: (((Value * Vref) / 1024) – 1.65) / 0.330 gives the correct value of acceleration along any axis of the accelerometer module. However, in order to make the equation work, we would need to plug in the values of the X-axis, Y-axis, and Z-axis separately in 3 different variables to obtain the value of acceleration along each individual axis.