MPS20N0040D

Scientific Background

1. Pressure Measurement Principle

The sensor uses MEMS piezoresistive technology. The output voltage ($V_{out}$) relates to applied pressure ($P$) by:

$$ V_{out} = V_{bias} + S \cdot P + \epsilon(T) $$

Where:

• $S$ = Sensitivity (-0.21%FS/°C, datasheet)
• $\epsilon(T)$ = Temperature error (±0.08%FS/°C)

2. Venturi Flow Equation

Flow rate ($Q$) is calculated using Bernoulli's principle:

$$ Q = A_1 \sqrt{\frac{2\Delta P}{\rho(1-\beta^4)}} $$

Where:

• $\beta = \frac{d_2}{d_1}$ (diameter ratio)
• $\rho$ = Fluid density (kg/m³)

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System Diagram

graph LR
  A[MPS20N0040D-S] -->|Differential mV| B[HX710 ADC]
  B -->|24-bit Data| C[Arduino]
  C --> D[Serial Monitor]
  C --> E[Control System]

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Wiring Diagram

The following is a description of the image:

1. The sensor, designated as MPS20N0040D-S, is connected to
   • Pin 1, identified as V+. It is to be connected to a 5V Microcontroller
   • Pin 2 (GND) is to be connected to: Connects to GND Microcontroller
   • Pin 3 (Vout+): Connects to IN+ HX710
   • Pin 4 (Vout-): Connects to IN- HX710

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Installation

1. Download the ZIP and install via Arduino IDE:
   Sketch > Include Library > Add .ZIP Library
2. Or clone to Arduino libraries folder:

   git clone https://github.com/4211421036/mps20n0040d-sensor.git

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Function Documentation

Function	Parameters	Description
begin()	-	Initializes sensor and ADC pins
readPressure()	-	Returns pressure in Pascals (Pa)
calculateFlowRate()	pressureDiff, density (optional)	Computes flow rate in m³/s

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Example Code

#include <MPS20N0040D.h>

// Pin definition
#define PD_SCK 3
#define DOUT 4

MPS20N0040D sensor(PD_SCK, DOUT);

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

void loop() {
  float pressure = sensor.readPressure();
  float flowRate = sensor.calculateFlowRate(pressure, 1000.0); // Water density
  
  Serial.print("Pressure: "); 
  Serial.print(pressure); 
  Serial.println(" Pa");
  
  Serial.print("Flow Rate: "); 
  Serial.print(flowRate * 1000, 2); // Convert to L/s
  Serial.println(" L/s");
  
  delay(1000);
}

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Calibration Procedure

1. Apply known pressures (0-40kPa) using a dead weight tester
2. Record ADC outputs
3. Update these constants in MPS20N0040D.cpp:

   const float V_REF = 5.0;    // Measured reference voltage
   const float FS_OUTPUT = 0.1; // Verified full-scale output

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Technical Specifications

Parameter	Value	Unit
Pressure Range	0-40	kPa
Accuracy	±0.25	% FS
Operating Voltage	2.6-5.5	V
Output Data Rate	10/80	SPS

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Author

1. Ana Maulida
2. GALIH RIDHO UTOMO

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