YF-S201 Hall effect Flow Sensor help getting code to return a value.

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1

I set up my YF-S201 flow meter with my Arduino Uno board and had it working fine.

I then tried to replicate it using a LoLin Node MCU V3 ESp 8266

I copied the code across and modified the interrupt function using ICACHE_RAM_ATTR to get it running OK.

However I am just getting 0 returned as the flowrate even if I blow through the meter.

Can anyone see where my code may be wrong for the device?

Code below:

Thanks

volatile int  flow_frequency;  // Measures flow meter pulses
unsigned int  l_hour;          // Calculated litres/hour                      
unsigned char flowmeter = D2;  // Flow Meter Pin number
unsigned long currentTime;
unsigned long cloopTime;

void ICACHE_RAM_ATTR flow ()                  // Interrupt function
{ 
   flow_frequency++;
} 

void setup()
{ 
   pinMode(flowmeter, INPUT);
   Serial.begin(9600); 
   attachInterrupt(0, flow, RISING); // Setup Interrupt 
                                     // see http://arduino.cc/en/Reference/attachInterrupt
   sei();                            // Enable interrupts  
   currentTime = millis();
   cloopTime = currentTime;
} 

void loop ()    
{
   currentTime = millis();
   // Every second, calculate and print litres/hour
   if(currentTime >= (cloopTime + 1000))
   {     
      cloopTime = currentTime;              // Updates cloopTime
      // Pulse frequency (Hz) = 7.5Q, Q is flow rate in L/min. (Results in +/- 3% range)
      l_hour = (flow_frequency * 60 / 7.5); // (Pulse frequency x 60 min) / 7.5Q = flow rate in L/hour 
      flow_frequency = 0;                   // Reset Counter
      Serial.print(l_hour, DEC);            // Print litres/hour
      Serial.println(" L/hour");
   }
}
2

Are you sure D2 is interrupt 0?

Why don't you use the digitalPinToInterrupt() function there instead, as explained a.o. here?