Pressure Sensor for Pressure cuff

Other Hardware Sensors
1

Need help in utilizing my pressure sensor ( MPS20N0040D)

The sensor always output 8388608 and does not recognize the pressure when the pressure cuff increases in pressure.

#include <SPI.h>
#include <Q2HX711.h>
#include <Average.h>

// Define the pin numbers for control
const int ENA = 5;           // Enable pin connected to ENA on L298N
const int IN1 = 2;           // Control pin 1 connected to IN1 on L298N
const int IN2 = 3;           // Control pin 2 connected to IN2 on L298N
const byte MPS_OUT_pin = 8;  // OUT data pin
const byte MPS_SCK_pin = 9;  // clock data pin
int avg_size = 10;           // #pts to average over

Q2HX711 MPS20N0040D(MPS_OUT_pin, MPS_SCK_pin); // start comm with the HX710B
Average<long> ave(avg_size);

// Conversion factor from sensor output to mmHg (replace 1 with your actual conversion factor)
const float CONVERSION_FACTOR = 1.0; 

void setup() {
  Serial.begin(9600); // start the serial port
  // Initialize the control pins as outputs
  pinMode(ENA, OUTPUT);
  pinMode(IN1, OUTPUT);
  pinMode(IN2, OUTPUT);
}

void loop() {
  // Turn on the air pump
  digitalWrite(ENA, HIGH);   // Enable the motor driver
  digitalWrite(IN1, HIGH);   // Set IN1 HIGH
  digitalWrite(IN2, LOW);    // Set IN2 LOW
  ave.push(MPS20N0040D.read());
  
  // Convert the pressure reading to mmHg and print
  float pressure_mmHg = ave.mean() * CONVERSION_FACTOR;
  Serial.println(pressure_mmHg);
}

image
image1067×800 63.2 KB

2

Try dropping the ave stuff and see what raw data you're getting.

4

I have removed the average stuff in the code, still the readings in the serial monitor is around 8388608 when it should be growing since I also have attached a pressure reader in the pipe

5

Please post the new code.

6 
#include <SPI.h>
#include <Q2HX711.h>

// Define the pin numbers for control
const int ENA = 5;           // Enable pin connected to ENA on L298N
const int IN1 = 2;           // Control pin 1 connected to IN1 on L298N
const int IN2 = 3;           // Control pin 2 connected to IN2 on L298N
const byte MPS_OUT_pin = 8;  // OUT data pin
const byte MPS_SCK_pin = 9;  // clock data pin

Q2HX711 MPS20N0040D(MPS_OUT_pin, MPS_SCK_pin); // start comm with the HX710B

// Conversion factor from sensor output to mmHg (replace 1 with your actual conversion factor)
const float CONVERSION_FACTOR = 1.0; 

void setup() {
  Serial.begin(9600); // start the serial port
  // Initialize the control pins as outputs
  pinMode(ENA, OUTPUT);
  pinMode(IN1, OUTPUT);
  pinMode(IN2, OUTPUT);
}

void loop() {
  // Turn on the air pump
  digitalWrite(ENA, HIGH);   // Enable the motor driver
  digitalWrite(IN1, HIGH);   // Set IN1 HIGH
  digitalWrite(IN2, LOW);    // Set IN2 LOW
  
  // Read the pressure sensor
  long pressure_raw = MPS20N0040D.read();

  // Convert the pressure reading to mmHg and print
  float pressure_mmHg = pressure_raw * CONVERSION_FACTOR;
  Serial.println(pressure_mmHg);

  // Optional delay to slow down the readings (adjust as needed)
  delay(1000); // 1 second delay
}
7

Here is the new code sir

8

Could it be a wiring issue? How did you put it together?

9

You should have received a float.

10

is 0x800000 if that gives any useful clues.

1 Like
11

The module I see is a HX710, not a HX711.
Use a HX710 library for starters.
Leo..

12

Hello, thank you for the help everyone, I was able to find the issue. Apparently, the sensor is really sensitive there should be a certain curve in the tube attached then it will detect the pressure. I calibrated the raw data by making an equation by matching the raw data with its corresponding pressure gauge.

13

This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.