Code

// Define the input pin for the flow meter
const int flowMeterPin = 2; // Example pin, adjust as needed

// Variables to store flow rate and pulse count
volatile unsigned int pulseCount;
float flowRate;

// Timer variables
unsigned long startTime;
unsigned long currentTime;

void setup() {
  Serial.begin(9600); // Initialize serial communication
  
  // Attach interrupt for flow meter pulse
  attachInterrupt(digitalPinToInterrupt(flowMeterPin), pulseCounter, FALLING);
  
  // Initialize variables
  pulseCount = 0;
  flowRate = 0.0;
  startTime = millis(); // Start time for flow rate calculation
}

void loop() {
  // Calculate flow rate every second
  currentTime = millis();
  if (currentTime - startTime >= 1000) {
    detachInterrupt(digitalPinToInterrupt(flowMeterPin)); // Disable interrupts during calculation
    flowRate = pulseCount / 7.5; // Convert pulse count to flow rate (example conversion, adjust based on sensor specifications)
    pulseCount = 0; // Reset pulse count
    startTime = currentTime; // Update start time

    // Display flow rate on serial monitor
    Serial.print("Flow Rate: ");
    Serial.print(flowRate);
    Serial.println(" L/min");

    // Display "CLEAN THE PIPE!" message if flow rate is zero
    if (flowRate == 0.0) {
      Serial.println("CLEAN THE PIPE!");
    }

    attachInterrupt(digitalPinToInterrupt(flowMeterPin), pulseCounter, FALLING); // Re-enable interrupts
  }
}

// Interrupt service routine to count pulses
void pulseCounter() {
  pulseCount++;
}