How to Use mpx5100dp Pressure Sensor: Examples, Pinouts, and Specs

The MPX5100DP is a piezoresistive pressure sensor manufactured by MPX Pressure Sensors. It provides an analog output voltage proportional to the applied pressure, making it ideal for precise pressure measurement. The sensor is designed to measure pressures in the range of 0 to 100 kPa (kilopascals) and is commonly used in applications such as:

• HVAC (Heating, Ventilation, and Air Conditioning) systems
• Automotive systems (e.g., manifold air pressure measurement)
• Industrial equipment and process control
• Medical devices (e.g., respiratory systems)

The MPX5100DP features dual ports for differential pressure measurement, allowing it to measure the difference between two pressure sources.

The MPX5100DP has a 6-pin configuration. The table below describes each pin:

1. Power Supply: Connect the V_cc pin to a regulated 5V power supply and the GND pin to the ground of the circuit.
2. Output Signal: The V_out pin provides an analog voltage proportional to the applied pressure. This output can be read using an ADC (Analog-to-Digital Converter) on a microcontroller, such as an Arduino UNO.
3. Pressure Ports: The MPX5100DP has two ports:
   • Port P1: High-pressure port (positive pressure input)
   • Port P2: Low-pressure port (reference or negative pressure input)
   • For absolute pressure measurement, leave P2 open to the atmosphere.

• Filtering: Add a decoupling capacitor (e.g., 0.1 µF) between V_cc and GND to reduce noise.
• Pressure Range: Ensure the applied pressure does not exceed the sensor's maximum rating of 100 kPa to avoid damage.
• Temperature Effects: The sensor is temperature-compensated, but extreme temperatures may still affect accuracy.
• Mounting: Avoid applying mechanical stress to the sensor during installation to maintain accuracy.

Below is an example of how to connect the MPX5100DP to an Arduino UNO and read the pressure:

• MPX5100DP V_cc → Arduino 5V
• MPX5100DP GND → Arduino GND
• MPX5100DP V_out → Arduino A0 (Analog Pin)

// MPX5100DP Pressure Sensor Example Code
// Reads the analog output from the sensor and calculates the pressure in kPa.

const int sensorPin = A0; // Analog pin connected to Vout of MPX5100DP
const float Vcc = 5.0;    // Supply voltage to the sensor
const float VoutMin = 0.2; // Minimum output voltage (0 kPa)
const float VoutMax = 4.7; // Maximum output voltage (100 kPa)
const float pressureMax = 100.0; // Maximum pressure in kPa

void setup() {
  Serial.begin(9600); // Initialize serial communication
}

void loop() {
  int sensorValue = analogRead(sensorPin); // Read the analog value (0-1023)
  float voltage = (sensorValue / 1023.0) * Vcc; // Convert to voltage
  float pressure = ((voltage - VoutMin) / (VoutMax - VoutMin)) * pressureMax;

  // Print the pressure value to the Serial Monitor
  Serial.print("Pressure: ");
  Serial.print(pressure);
  Serial.println(" kPa");

  delay(1000); // Wait for 1 second before the next reading
}

1. No Output Voltage:

   • Ensure the sensor is powered with a regulated 5V supply.
   • Check all connections, especially V_cc, GND, and V_out.

2. Inaccurate Pressure Readings:

   • Verify that the pressure applied is within the sensor's range (0 to 100 kPa).
   • Check for noise in the power supply and add a decoupling capacitor if needed.
   • Ensure the reference port (P2) is open to the atmosphere for absolute pressure measurements.

3. Fluctuating Output:

   • Use a stable power supply and ensure proper grounding.
   • Add a low-pass filter to the output to reduce noise.

Q: Can the MPX5100DP measure negative pressure?
A: Yes, the MPX5100DP can measure differential pressure. If the pressure at P2 is higher than P1, the output voltage will decrease accordingly.

Q: What is the response time of the sensor?
A: The MPX5100DP has a response time of 1 ms, making it suitable for real-time applications.

Q: Can I use the MPX5100DP with a 3.3V microcontroller?
A: The MPX5100DP requires a 5V supply for proper operation. If your microcontroller operates at 3.3V, use a level shifter or ADC with 5V tolerance to interface with the sensor.

This concludes the documentation for the MPX5100DP Pressure Sensor.