int sensorPin = D3;
int ledPin = D2;

void setup() {
    pinMode(ledPin, OUTPUT);
    Particle.subscribe("blinkLED", handleActivateLED);
    blinkLED(3, ledPin);
}

unsigned long readQTR() {
    unsigned long duration = 0;
    pinMode(sensorPin, OUTPUT);
    digitalWrite(sensorPin, HIGH);
    delayMicroseconds(10);
    pinMode(sensorPin, INPUT);
    while(digitalRead(sensorPin) == HIGH) {
        duration++;
        if(duration > 3000) break;
    }
    return duration;
}

void loop() {
    unsigned long sensorValue = readQTR();
    if(sensorValue < 3000) {
        digitalWrite(ledPin, HIGH);
        Particle.publish("doPairedPublish");
    } else {
        digitalWrite(ledPin, LOW);
    }
    delay(100);
    if(doBlink) {
        blinkLED(6, ledPin);
        doBlink = false;
    }
}

void blinkLED( int times, int pin ){
    
    for( int i = 0; i < times ; i++ ){
        digitalWrite( pin, HIGH );
        delay( 500 );
        digitalWrite( pin, LOW );
        delay( 500 );
    }
    
}

void handleActivateLED( const char *event, const char *data)
{
   doBlink = true;
}