Honeywell NBP series pressure sensor - How to get the pressure readings

Dear all,

I am trying to get pressure reading from the Honeywell NBPDLNN030PAUNV pressure sensor using a Arduino Mega board. This is an absolute pressure sensor measuring 0 to 30 PSI (Datasheet attached - Page 4, table 6, highlighted in yellow). I have used some analogue sensors (e.g. LM35) in past in with only 1 pin which gives the positive out voltage which we can use to get the temperature. This sensor has two voltage out pins one with Negative voltage (Vout-) and one with positive voltage (Vout+) (table 8 in the attached datasheet). Furthermore, the offset has a range of -7.0 mV to +7.0 mV and the sensitivity is also from 15.5 mV to 26.0 mv. I tried to take the pressure reading from both Vout- and Vout+ separately using the logic

  const float Null = 0.00; // Null VDC
  const float Sensitivity = 21.0;  // Sensitivity 
  pressure = analogRead(ADC_HONEYWELL);
  pressureVDC = (float)pressure * 0.0048828125; // (5/1024 = 0.0048828125)
  pressureVDC = pressureVDC - Null;
  pressurePSI = pressureVDC / Sensitivity * 1000;

None of the pin is giving me correct readings. Please let me know how should I write a code to obtain correct pressure readings. I have also searched on the internet but could not get any details about the code to get the pressure. Do I need to connect the Vout- and Vout+ pins some how and then take the pressure reading or do I need to include both Vout- and Vout+ in some logic to find the correct pressure readings.

I am novice to sensors/automation/electronics. Could someone please suggest me a good blog/tutorial/book which I can follow to get started in this field.

Waiting for your reply!!


NBPDLNN030PAUNV_PressureSensor.pdf (431 KB)

Looks like this sensor contains a Wheatstone bridge. U'll need an instrument amplifier (or two rail to rail OP.AMPs) to get good results. One example is the INA125

The Honeywell NBP sensors are Wheatstone bridges without any amplification or signal conditioning of any kind. Therefore, you need to drive the bridge and amplify/condition the output yourself. A bridge output is the difference between two sides of the bridge, so you will need an instrumentation amplifier (in-amp) or discrete op-amps configured as an in-amp to do this. Simply measuring the output of one side of the bridge to ground will not give you the correct readings.

Look at this application node: