What does the output of ADXL335 in degrees represents?

Other Hardware Sensors
1

Hello all,

I am currently doing a project which includes the accelerometer ADXL335. I have got the code from this site and it worked pretty well. But i am unable to understand the output. What does it represents in degrees? Does it represent anything related to gravity?

My code is :
#include <FileIO.h>

const int xPin = 0;
const int yPin = 1;
const int zPin = 2;

//The minimum and maximum values that came from
//the accelerometer while standing still
//You very well may need to change these
int minVal = 265;
int maxVal = 402;
//to hold the calculated values
double x;
double y;
double z;
Void setup ()
{
Serial.begin (9600);
}
void loop(){
//read the analog values from the accelerometer
int xRead = analogRead(xPin);
int yRead = analogRead(yPin);
int zRead = analogRead(zPin);

//convert read values to degrees -90 to 90 - Needed for atan2
int xAng = map(xRead, minVal, maxVal, -90, 90);
int yAng = map(yRead, minVal, maxVal, -90, 90);
int zAng = map(zRead, minVal, maxVal, -90, 90);

//Calculate 360deg values like so: atan2 (-yAng, -zAng)
//atan2 outputs the value of -? to ? (radians)
//We are then converting the radians to degrees
x = RAD_TO_DEG * (atan2 (-yAng, -zAng) + PI);
y = RAD_TO_DEG * (atan2 (-xAng, -zAng) + PI);
z = RAD_TO_DEG * (atan2 (-yAng, -xAng) + PI);

//Output the calculation
Serial.print (", ");
Serial.print(x);
Serial.print (“, ");
Serial.print(y);
Serial.print (“, ");
Serial.println (z);
delay (1000);
}

My output is attached below

Looking forward to hear from you,

Regards,
Koduri

arduino.png
arduino.png1152×648 134 KB

2

That program is intended to calculate tilt angles, but is partly nonsense. You should ignore it.

3

Can you say where can I find the code to find the acceleration ?

4

Here you read out the acceleration values.

   //read the analog values from the accelerometer
  int xRead = analogRead(xPin);
  int yRead = analogRead(yPin);
  int zRead = analogRead(zPin);

The data sheet for the device will tell you how to interpret the numbers.

5

Hello,

I got the x,y,z reading with respective to "g". The thing is i have placed the accelerometer on the tip of the index finger . Now i am doing a test in which i will tap the index finger on to the thumb finger. I would like to find the distance between the index and thumb finger at respective time instants.

Is it possible?

Looking forward to hear from you,

Regards,
Koduri

6

Theoretically, it is possible. In practise, probably not.