Modifying the clock rate for shiftin()

Projects Programming
2

The file is "wiring_shift.c", and in my installation, it's located in "\Arduino\hardware\arduino\avr\cores\arduino".

This is the function:-

uint8_t shiftIn(uint8_t dataPin, uint8_t clockPin, uint8_t bitOrder)
{
	uint8_t value = 0;
	uint8_t i;

	for (i = 0; i < 8; ++i)
        {
		digitalWrite(clockPin, HIGH);
		if (bitOrder == LSBFIRST)
			value |= digitalRead(dataPin) << i;
		else
			value |= digitalRead(dataPin) << (7 - i);
		digitalWrite(clockPin, LOW);
	}
	return value;
}