accelerometer problems

Using Arduino Sensors
1

Hey,
Im using an adxl335 accelerometer, im using an old version of arduino which does not have a 3.3V pin so im using an external 3V supply to power my sensor.The problem is that when i run the program to light up an led when a tilt is detected, the led lights up, but the accelerometer readings gets boosted whenever the led lights up and gets lowered whenever the led goes low.I get the output:
accelerations are x, y, z : 396 391 483//when in stable position and led is ON
accelerations are x, y, z : 396 391 483
accelerations are x, y, z : 396 391 483
accelerations are x, y, z : 396 391 483
accelerations are x, y, z : 351 348 430//it gets lowered when the led turns off while it is still in stable mode
accelerations are x, y, z : 351 348 430
accelerations are x, y, z : 351 348 430
Please help:

int x,y,z;


void setup()
{
  Serial.begin(9600);      // sets the serial port to 9600
pinMode(7,OUTPUT);
pinMode(6,OUTPUT);
pinMode(5,OUTPUT);
pinMode(4,OUTPUT);
pinMode(3,OUTPUT);
}

void loop() 
{
  x = analogRead(0);       // read analog input pin 0
  y = analogRead(1);       // read analog input pin 1
  z = analogRead(2);       // read analog input pin 1
  Serial.print("accelerations are x, y, z: ");
  Serial.print(x, DEC);    // print the acceleration in the X axis
  Serial.print(" ");       // prints a space between the numbers
  Serial.print(y, DEC);    // print the acceleration in the Y axis
  Serial.print(" ");       // prints a space between the numbers
  Serial.println(z, DEC);  // print the acceleration in the Z axis
 if( y > 290 && z < 340)//up
 {
   digitalWrite(7,HIGH);
 }
 else digitalWrite(7,LOW);
 
 if( x<270 && y<270 && z<340)//down
 {
   digitalWrite(6,HIGH);
 }
 else digitalWrite(6,LOW);
 if ( x>260 && x<286 && y<290 && y>240 && z<350 && z>315)//centre
 {
   digitalWrite(5,HIGH);
 }
 else digitalWrite(5,LOW);
 if(x>298 && y>282 && z>310)//right
 {
   digitalWrite(4,HIGH);
 }
   else digitalWrite(4,LOW);
   if(x<235 && y<275 && z<318)//left
   {
     digitalWrite(3,HIGH);
   }
   else digitalWrite(3,LOW);
    
  delay(600);              // wait 100ms for next reading
}
2

I don't know if your problem comes from your code or your circuit so why not showing both? I suspect you didn't have a correct circuit for the LED, which affects the supply voltage of arduino large enough to affect you but without a circuit picture I can only suspect.

3

I wired my leds from digital 7,6,5,4,3 to all the led's +ve pin and connected the ground of all leds together to arduino ground.Then for my accelerometer i wired the 5V from my arduino to 3 Si diodes with voltage taken accross a 1K resistor(this forms the 3.3V to power my accelerometer) connected to 3.3V pin of the sensor, ground of sensor to arduino ground and the X-acc,Y-acc,Z-acc pins of the sensor to analog 0,1,2 pins of arduino.......!!Please help.

4

This description spells a lot of trouble. If you had a newer version of arduino, you would have asked a question:"why is my arduino restarting all the time and USB connect/disconnect sound kept playing?"

Please stop what you're doing. You're hurting your arduino. Take a good picture of your connections and we can give you corrections using the picture and your description.