Working with Accelerometer

Sreerag Sreenath

10 March 2016

This week I have worked on interfacing accelerometer with Arduino. The following are the complied results on the module. I have also included some of the research papers which I refered to.

What is accelerometer?

An accelerometer is a device that measures proper acceleration (“g-force”). Proper acceleration is not the same as coordinate acceleration (rate of change of velocity).

Which Accelerometer did we purchase?

ADXL335 is a small, thin, low power, complete 3-axis accelero-meter with signal conditioned voltage outputs. The product measures acceleration with a minimum full-scale range of ±3 g. It can measure the static acceleration of gravity in tilt-sensing applications, as well as dynamic acceleration resulting from motion, shock, or vibration. ADXL335 is 3v3 compatible device, it’s powered by a 3.3v source and also generates 3.3v peak outputs. It has three outputs for each axis i.e. X, Y & Z. These are analog outputs and thus require an ADC in a micro-controller. Arduino solves this problem. We will be using the analog functions of Arduino.

Arduino Interfacing with accelerometer

The accelerometer module has 5 pins, namely

1. GND-To be connected to Arduino's GND
2. VCC-To be connected to Arduino's 5V
3. X-To be connected to Analog Pin A5
4. Y-To be connected to Analog Pin A4
5. Z-To be connected to Analog Pin A3

NOTE: We don’t need to power the module from 3.3v because it already has a 5v to 3.3v converter.
Use 2-pin relimate for connecting Vcc and GND. Use a 3-pin relimate for connecting X, Y & Z outputs. Also connect AREF pin to the 3.3v. This is done to set the reference voltage to 3.3v because the output of ADXL335 is 3.3v compatible.