Переписываю библиотеку DHT sensor (arduino). Непонятки по структуре

// Turn off interrupts temporarily because the next sections are timing critical
// and we don't want any interruptions.
interruptLock();
// End the start signal by setting data line high for 40 microseconds.
digitalWrite(_pin, HIGH);
delayMicroseconds(40);
// Now start reading the data line to get the value from the DHT sensor.
pinMode(_pin, INPUT_PULLUP);
delayMicroseconds(10); // Delay a bit to let sensor pull data line low.
// First expect a low signal for ~80 microseconds followed by a high signal
// for ~80 microseconds again.
if (expectPulse(LOW) == 0) {
    DEBUG_PRINTLN(F("Timeout waiting for start signal low pulse."));
    _lastresult = false;
    interruptUnlock();
    return _lastresult;
}
if (expectPulse(HIGH) == 0) {
    DEBUG_PRINTLN(F("Timeout waiting for start signal high pulse."));
    _lastresult = false;
    interruptUnlock();
    return _lastresult;
}
// Now read the 40 bits sent by the sensor. Each bit is sent as a 50
// microsecond low pulse followed by a variable length high pulse. If the
// high pulse is ~28 microseconds then it's a 0 and if it's ~70 microseconds
// then it's a 1. We measure the cycle count of the initial 50us low pulse
// and use that to compare to the cycle count of the high pulse to determine
// if the bit is a 0 (high state cycle count < low state cycle count), or a
// 1 (high state cycle count > low state cycle count). Note that for speed all
// the pulses are read into a array and then examined in a later step.
for (int i=0; i<80; i+=2) {
    cycles[i] = expectPulse(LOW);
    cycles[i+1] = expectPulse(HIGH);
}
interruptUnlock();
// Timing critical code is now complete.