//*******************************************************
//  FlowMeter
//*******************************************************
void setupFlowMeter() {
  pinMode(hallsensor, INPUT); //initializes digital pin 2 as an input
  attachInterrupt(0, pulseCounter, RISING); //and the interrupt is attached
  loopTime = millis();
  sei();  //enable interupts
}
void pulseCounter() {               //This is the function that the interupt calls 
  pulseCount++;              //This function measures the rising and falling edge of the hall effect sensors signal
} 
void checkFlow() {
    if(millis() >= (loopTime + 2000)){  
      Calc = (pulseCount * 60 / (7.5 * 2)); //(Pulse frequency x 60) / 7.5Q, = flow rate in L/hour 
      flowMenu();
      pulseCount = 0;
      loopTime = millis();;  // Updates loopTime
    }
}