Introduction: Interfacing ADXL335 With ARDUINO

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About: An electronics enthusiast... #Complexity simplified

As the datasheet says, 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.

Step 1: Parts Required

  1. Arduino-Any Arduino/clone will do but I have used Freeduino v1.16
  2. ADXL335 accelerometer
  3. Connecting wires(Relimates)
  4. USB cable for connecting Arduino with your Laptop

Step 2: The Circuit

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.

Step 3: Code




//connect 3.3v to AREF


const int ap1 = A5; 
const int ap2 = A4;
const int ap3 = A3;

int sv1 = 0;        
int ov1 = 0;    
int sv2 = 0;      
int ov2= 0;      
int sv3 = 0;       
int ov3= 0;      

void setup() {
  // initialize serial communications at 9600 bps:
  Serial.begin(9600);

}

void loop() {
  analogReference(EXTERNAL);    //connect 3.3v to AREF
  // read the analog in value:
  sv1 = analogRead(ap1);            
  // map it to the range of the analog out:
  ov1 = map(sv1, 0, 1023, 0, 255);  
  // change the analog out value:
  delay(2);                     
  //
  sv2 = analogRead(ap2);            

  ov2 = map(sv2, 0, 1023, 0, 255); 
 // 
  delay(2);                 
  //
  sv3 = analogRead(ap3);            

  ov3 = map(sv3, 0, 1023, 0, 255);  

  // print the results to the serial monitor:
  Serial.print("Xsensor1 = " );                       
  Serial.print(sv1);      
  Serial.print("\t output1 = ");      
  Serial.println(ov1);   

  Serial.print("Ysensor2 = " );                       
  Serial.print(sv2);      
  Serial.print("\t output2 = ");      
  Serial.println(ov2);   

  Serial.print("Zsensor3 = " );                       
  Serial.print(sv3);      
  Serial.print("\t output3 = ");      
  Serial.println(ov3);   

  delay(3000);                     

}

Step 4: Serial Monitor

We will be displaying two different values for one analog value read. The first value is the ADC converted value in 10-bit resolution(0 to 1023) while the second one is mapped for PWM and it is in 8-bit resolution(0 to 255).
Three values for X, Y & Z axes are displayed together are repeated after an interval of 3 seconds.

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