Overview of ADXL335 Accelerometer 

An accelerometer is an electromechanical device that will measure acceleration forces. The accelerometer can measure the static acceleration of gravity in tilt-sensing applications as well as dynamic acceleration resulting from motion, shock, or vibration.

ADXL335 is a 3-axis accelerometer that provides analog output for acceleration along the x, y, and z-axis.

Accelerometer ADXL335 Pin Description

VCC (3.3 V): If in case of ADXL335 Module has on board a 3.3V regulator, then we can connect 5 V to this pin.

GND: Connect Ground to this pin.

X_OUT: This is X-axis analog output from ADXL335.

Y_OUT: This is Y axis analog output from ADXL335.

Z_OUT: This is Z axis analog output from ADXL335.

ST (Self-test): This is self-test pin of ADXL335. Let’s interface the ADXL335 module with ARM MBED.

To know more about how it works refer ADXL335 link in sensors and model.

Connection Diagram of ADXL335 with ARM MBED (LPC1768)

Accelerometer X, Y, and Z pins are connected to Analog input p15, p16, and p17 of ARM MBED respectively.

Example

Let’s interface Accelerometer ADXL335 with ARM MBED LPC1768 board and display this analog value (0-3.3) on the serial window.

Accelerometer ADXL335 code for LPC1768 ARM MBED 

#include "mbed.h"
AnalogIn x(p15); //connect x pin of accelerometer to p15 pin of ARM MBED
AnalogIn y(p16); //connect y pin of accelerometer to p16 pin of ARM MBED
AnalogIn z(p17); //connect z pin of accelerometer to p17 pin of ARM MBED
Serial pc(USBTX, USBRX); //tx, rx

int main()
{
	while(1)
	{
		pc.printf("Accelerometer X : %f\n\r", x.read()*3.3);
		pc.printf("Accelerometer Y : %f\n\r", y.read()*3.3);
		pc.printf("Accelerometer Z : %f\n\r", z.read()*3.3);
		pc.printf("\n");
		wait(1); //wait for 1 second 
	}
}

Output Serial Window

Here we can see ADXL335 analog raw value on serial port getting from X, Y, Z pin serially.