Pressure sensor not working

Hi, I am using a freescale semiconductor MPX4250AP pressure sensor for a project but somehow it doesn't work. I am using the arduino mega board and only using the 'analog read serial code' in the examples. (I am also using arduino 1.5.2)

  Reads an analog input on pin 0, prints the result to the serial monitor.
  Attach the center pin of a potentiometer to pin A0, and the outside pins to +5V and ground.

 This example code is in the public domain.

// the setup routine runs once when you press reset:
void setup() {
  // initialize serial communication at 9600 bits per second:

// the loop routine runs over and over again forever:
void loop() {
  // read the input on analog pin 0:
  int sensorValue = analogRead(A0);
  // print out the value you read:
  delay(1);        // delay in between reads for stability

What happens is that all I see in the serial monitor is 0.

I am fairly sure I have connected it correctly:

Pin 1 - analog input 0 Pin 2 - ground Pin 3 - 5V see attachment for picture

The weird thing is that when I switch the ground and 5V wires, all I see is 1023!

It was working before but somehow stopped! I have done nothing to damage it.

Is it faulty or am I doing something wrong?


First do measure the sensor's output with a voltmeter. You have to read about 1.8Volts.