Serialize bits from input/output pin with VHDL

// Return values:

// DHTLIB_OK              0 => OK
// DHTLIB_ERROR_CHECKSUM -1 => Checksum error
// DHTLIB_ERROR_TIMEOUT  -2 => Timeout


int read(int pin)
{
	
	uint8_t bits[5]; // BUFFER TO RECEIVE
	uint8_t cnt = 7; // bit counter 0..7
	uint8_t idx = 0; // buffer index

	// EMPTY BUFFER
	for (int i=0; i<5; i++) bits[i] = 0;

	// REQUEST SAMPLE
	pinMode(pin, OUTPUT);    // set pin for output
	digitalWrite(pin, LOW);  // write '0'
	delay(18);               // delay 18ms
	digitalWrite(pin, HIGH); // write '1'
	delayMicroseconds(40);   // delay 40 microseconds

	pinMode(pin, INPUT);     // set pin for input

	// ACKNOWLEDGE or TIMEOUT
	unsigned int loopCnt = 10000; 
	while(digitalRead(pin) == LOW)
		if (loopCnt-- == 0) return DHTLIB_ERROR_TIMEOUT;

	loopCnt = 10000;
	while(digitalRead(pin) == HIGH)
		if (loopCnt-- == 0) return DHTLIB_ERROR_TIMEOUT;

	// READ OUTPUT - 40 BITS => 5 BYTES or TIMEOUT
	for (int i=0; i<40; i++)
	{
		loopCnt = 10000;
		while(digitalRead(pin) == LOW)
			if (loopCnt-- == 0) return DHTLIB_ERROR_TIMEOUT;

		unsigned long t = micros();  // this function returns the timestamp in microseconds

		loopCnt = 10000;
		while(digitalRead(pin) == HIGH)
			if (loopCnt-- == 0) return DHTLIB_ERROR_TIMEOUT;

		if ((micros() - t) > 40) bits[idx] |= (1 << cnt);
		if (cnt == 0)   // next byte?
		{
			cnt = 7;    // restart at MSB
			idx++;      // next byte!
		}
		else cnt--;
	}

	// WRITE TO RIGHT VARS
              // as bits[1] and bits[3] are allways zero they are omitted in formulas.
	humidity    = bits[0]; 
	temperature = bits[2]; 

	uint8_t sum = bits[0] + bits[2];  

	if (bits[4] != sum) return DHTLIB_ERROR_CHECKSUM;
	return DHTLIB_OK;
}