Laser Water Flow sensor

#include <SevenSeg.h>

SevenSeg disp(1,8,3,4,5,6,7);            

const int numOfDigits=4;

int digitPins[numOfDigits]={12,11,10,9};

int buzzer=13;                      // initialize digital IO pin that controls the buzzer

int FlowPin = 2;  

double flowRate;

int lastFlow = -1;

int currentFlow = 0;

volatile int count;

const char *flowStrings[3] = { “OFF”, “HIGH”, “LO” };

void setup() {

  pinMode(buzzer,OUTPUT);            // set pin mode as “output”

  pinMode(FlowPin, INPUT);           //Sets the pin as an input

  attachInterrupt(0, Flow, RISING);  //Configures interrupt 0 (pin 2 on the Arduino Uno) to run the function “Flow”  

  disp.setDigitPins(numOfDigits, digitPins);

  disp.setTimer(2);

  disp.startTimer();

}  

void loop() {

  count = 0;      // Reset the counter so we start counting from 0 again

  interrupts();   //Enables interrupts on the Arduino

  delay (2000);   //Wait 2 seconds

  noInterrupts(); //Disable the interrupts on the Arduino

  flowRate = (count * 2.25);        //Take counted pulses in the last second and multiply by 2.25mL

  flowRate = flowRate * 60;         //Convert seconds to minutes, giving you mL / Minute

  flowRate = flowRate / 1000;       //Convert mL to Litres, giving you Litres / Minute

  if (flowRate < 1) {

    currentFlow = 0;

    digitalWrite(buzzer, HIGH);                 // produce sound

  } else if ((flowRate > 1) && (flowRate < 2)) {

    currentFlow = 2;

    digitalWrite(buzzer, LOW);

  } else {

    currentFlow = 1;

  }

  if (lastFlow != currentFlow) {

    disp.write(flowStrings[currentFlow]);

    lastFlow = currentFlow;

    digitalWrite(buzzer, LOW);

  }

 }

void Flow()

{

  count++; //Every time this function is called, increment “count” by 1

  }

ISR(TIMER2_COMPA_vect){

  disp.interruptAction();

}