액체 유량 센서를 사용하여 물의 양, 펄스값, 속도 구하기

https://m.blog.naver.com/PostView.naver?isHttpsRedirect=true&blogId=roboholic84&logNo=220534816162 

 

https://blog.daum.net/rockjjy99/2645

 

https://blog.naver.com/roboholic84/220540393392

 

https://youtu.be/rJrfkpOLaQs

액체가 흐르면 내장된 팬이 돌아가고, 그 돌아간 횟수와 빠르기를 측정하여

액체의 양, 펄스값, 속도를 측정할 수 있는 센서입니다.

5V 전압으로 사용할 수 있고, 출력값은 디지털 신호입니다.

 

 

액체 유량 센서의 원리

 

이 센서의 측정원리는 접선류 날개차 방식입니다.

유입구에서 물을 흘러보내면, 날개차를 거쳐 유출구로 빠져나옵니다.

그 과정에서 물의 양에 비례하여 날개차가 회전을 하게 되며,

물의 속도에 비례해 날개차의 회전속도가 변합니다.

즉, 회전횟수에 비례해 물의 양을 구할 수 있으며

회전속도에 비례해 물의 속도를 구할 수 있습니다.

 

이 센서의 초당 시그널 수를 구하는 공식은 

초당 시그널 수 = 8.1 * 분당 유량 - 3 입니다. [ Hz = 8.1 * Flow rate(L/min) - 3 ]

이 공식을 이용하여 초당 유량을 구할 수 있습니다.

 

(초당 시그널 수-3)/8.1 = 분당 유량이며

(초당 시그널 수 - 3 ) / 486 = 초당 유량입니다.

 

 

유량 센서로 유량 측정하기

 

준비물 : 아두이노 우노, LCD , 유량 센서, 가변저항 1개 , 다량의 점프선, 외부 전원

 

#include "LiquidCrystal.h"
LiquidCrystal lcd(7, 8, 9, 10, 11, 12);

// which pin to use for reading the sensor? can use any pin!
#define FLOWSENSORPIN 2

// count how many pulses!
volatile uint16_t pulses = 0;
// track the state of the pulse pin
volatile uint8_t lastflowpinstate;
// you can try to keep time of how long it is between pulses
volatile uint32_t lastflowratetimer = 0;
// and use that to calculate a flow rate
volatile float flowrate;
// Interrupt is called once a millisecond, looks for any pulses from the sensor!
SIGNAL(TIMER0_COMPA_vect) {
  uint8_t x = digitalRead(FLOWSENSORPIN);
  
  if (x == lastflowpinstate) {
    lastflowratetimer++;
    return; // nothing changed!
  }
  
  if (x == HIGH) {
    //low to high transition!
    pulses++;
  }
  lastflowpinstate = x;
  flowrate = 1000.0;
  flowrate /= lastflowratetimer;  // in hertz
  lastflowratetimer = 0;
}

void useInterrupt(boolean v) {
  if (v) {
    // Timer0 is already used for millis() - we'll just interrupt somewhere
    // in the middle and call the "Compare A" function above
    OCR0A = 0xAF;
    TIMSK0 |= _BV(OCIE0A);
  } else {
    // do not call the interrupt function COMPA anymore
    TIMSK0 &= ~_BV(OCIE0A);
  }
}

void setup() {
   Serial.begin(9600);
   Serial.print("Flow sensor test!");
   lcd.begin(16, 2);
   
   pinMode(FLOWSENSORPIN, INPUT);
   digitalWrite(FLOWSENSORPIN, HIGH);
   lastflowpinstate = digitalRead(FLOWSENSORPIN);
   useInterrupt(true);
}

void loop()                     // run over and over again
{ 
  lcd.setCursor(0, 0);
  lcd.print("Pulses:"); lcd.print(pulses, DEC);
  lcd.print(" Hz:");
  lcd.print(flowrate);
  //lcd.print(flowrate);
  Serial.print("Freq: "); Serial.println(flowrate);
  Serial.print("Pulses: "); Serial.println(pulses, DEC);
  
  // if a plastic sensor use the following calculation
  // Sensor Frequency (Hz) = 7.5 * Q (Liters/min)
  // Liters = Q * time elapsed (seconds) / 60 (seconds/minute)
  // Liters = (Frequency (Pulses/second) / 7.5) * time elapsed (seconds) / 60
  // Liters = Pulses / (7.5 * 60)
  float liters = pulses;
  liters /= 7.5;
  liters /= 60.0;

/*
  // if a brass sensor use the following calculation
  float liters = pulses;
  liters /= 8.1;
  liters -= 6;
  liters /= 60.0;
*/
  Serial.print(liters); Serial.println(" Liters");
  lcd.setCursor(0, 1);
  lcd.print(liters); lcd.print(" Liters        ");
 
  delay(1000);
}

//소스 파일은 첨부하였습니다.https://blog.naver.com/roboholic84/220540393392

#include "LiquidCrystal.h"
LiquidCrystal lcd(7, 8, 9, 10, 11, 12);

// which pin to use for reading the sensor? can use any pin!
#define FLOWSENSORPIN 2

// count how many pulses!
volatile uint16_t pulses = 0;
// track the state of the pulse pin
volatile uint8_t lastflowpinstate;
// you can try to keep time of how long it is between pulses
volatile uint32_t lastflowratetimer = 0;
// and use that to calculate a flow rate
volatile float flowrate;
// Interrupt is called once a millisecond, looks for any pulses from the sensor!
SIGNAL(TIMER0_COMPA_vect) {
  uint8_t x = digitalRead(FLOWSENSORPIN);
  
  if (x == lastflowpinstate) {
    lastflowratetimer++;
    return; // nothing changed!
  }
  
  if (x == HIGH) {
    //low to high transition!
    pulses++;
  }
  lastflowpinstate = x;
  flowrate = 1000.0;
  flowrate /= lastflowratetimer;  // in hertz
  lastflowratetimer = 0;
}

void useInterrupt(boolean v) {
  if (v) {
    // Timer0 is already used for millis() - we'll just interrupt somewhere
    // in the middle and call the "Compare A" function above
    OCR0A = 0xAF;
    TIMSK0 |= _BV(OCIE0A);
  } else {
    // do not call the interrupt function COMPA anymore
    TIMSK0 &= ~_BV(OCIE0A);
  }
}

void setup() {
   Serial.begin(9600);
   Serial.print("Flow sensor test!");
   lcd.begin(16, 2);
   
   pinMode(FLOWSENSORPIN, INPUT);
   digitalWrite(FLOWSENSORPIN, HIGH);
   lastflowpinstate = digitalRead(FLOWSENSORPIN);
   useInterrupt(true);
}

void loop()                     // run over and over again
{ 
  lcd.setCursor(0, 0);
  lcd.print("Pulses:"); lcd.print(pulses, DEC);
  lcd.print(" Hz:");
  lcd.print(flowrate);
  //lcd.print(flowrate);
  Serial.print("Freq: "); Serial.println(flowrate);
  Serial.print("Pulses: "); Serial.println(pulses, DEC);
  
  // if a plastic sensor use the following calculation
  // Sensor Frequency (Hz) = 7.5 * Q (Liters/min)
  // Liters = Q * time elapsed (seconds) / 60 (seconds/minute)
  // Liters = (Frequency (Pulses/second) / 7.5) * time elapsed (seconds) / 60
  // Liters = Pulses / (7.5 * 60)
  float liters = pulses;
  liters /= 7.5;
  liters /= 60.0;
 
  Serial.print(liters); Serial.println(" Liters");
  lcd.setCursor(0, 1);
  lcd.print(liters); lcd.print(" Liters        ");
 
  delay(1000);
}