Hookup suggestions for connecting a Photon to a pulsing energy meter

Hardware
5

Ended upp with the following hookup,with an Active High circuit (following the left figure).

GND ---\
       |
       O 10k
       |
D3 ----+------ 41

3v3 -----------42
```

This is my code:
```cpp
/* 
Pulse counter to measure used kWh and calculate current W usage from a GM3D
*/

// According to EN62052-31 pulse lenght are ≥100ms <120 msec (ON)
byte minPulseWidth = 99;

unsigned long pulseTime=0;
volatile unsigned int pulseCount=0;
volatile unsigned long pulsePower=0;


    
void blink() {
  if ( (millis() - pulseTime) > minPulseWidth) {
    pulseCount++;
    //GM3D outputs 100 pulses/kWh (60m*60s*1000ms*10 = 36'000'000)
    pulsePower = 36000000 / (millis() - pulseTime); 
    pulseTime = millis();
  }
}

void setup() {
  pinMode(D3, INPUT);  
  attachInterrupt(D3, blink, RISING);
}

void loop() {
String data = "power:" + String(pulsePower) 
    + ",count:" + String(pulseCount)
  Spark.publish("data", data);
  delay(5000);
}
```

The results looks pretty promising. 

Thank you for all help!