problem with my pressure sensor HK1100c

Other Hardware Sensors
1

I have connected pressure sensor hk1100c properly to arduino due.code is fine but values i get from sensor output randomly changes.like i am using bar unit so it keep on changing in a range of -0.20 to 0.20
why is it happening?i don't get that.when it is not connected to any pressure(keeping atmospheric pressure constant) then it should give a specific value or may be a a variation of 0.01 or 0.02 but not more than that.
so kindly help me with this mess.

[select]

void setup()
{
  Serial.begin(9600);
}

void loop()
{
  int sensorVal = analogRead(A0);
  float voltage = (sensorVal*5.0)/1024.0; // converting sensorVal into voltage.
  Serial.print("\nVoltage: ");
  Serial.print(voltage);

  float pressure_pascal = (3.0* ((float)voltage-0.75) )* 1000000.0;
  float pressure_bar = pressure_pascal/10e5; // for pressure in bars unit.
  Serial.print("\nPressure = ");
  Serial.print(pressure_bar);
  Serial.print(" bars");



  delay(1000);
}
2

What is your ADC reading at 0 pressure? Should be near 104.
See if this helps out, change "adcMin" to whatever your 0 pressure ADC value is.

int adcMin = 104, // ADC reading @ 0 pressure
    adcMax = 921; //  "     "    " 12 Bar
float pressure, 
      pressureMax = 12.0;

void setup()
{
  Serial.begin(9600);
   
}

void loop()
{
  pressure = (analogRead(A0) - adcMin) / float((adcMax - adcMin)) * pressureMax;
  Serial.println(pressure);
  delay (1000);
}

If you still have problem with "jitter" you might try a 100nF ceramic capacitor from pin A0 to GND, or you may need a "smoothing" routine in your code.

3

you mean sensor value
lowest is 142 and
highest 170