Description
Shifts out a byte of data one bit at a time. Starts from either the most (i.e. the leftmost) or least (rightmost) significant bit. Each bit is written in turn to a data pin, after which a clock pin is pulsed (taken high, then low) to indicate that the bit is available.
Note- if you’re interfacing with a device that’s clocked by rising edges, you’ll need to make sure that the clock pin is low before the call to shiftOut()
, e.g. with a call to digitalWrite(clockPin, LOW)
.
This is a software implementation; see also the SPI library, which provides a hardware implementation that is faster but works only on specific pins.
Syntax
shiftOut(dataPin, clockPin, bitOrder, value)
Parameters
dataPin
: the pin on which to output each bit (int)
clockPin
: the pin to toggle once the dataPin has been set to the correct value (int)
bitOrder
: which order to shift out the bits; either MSBFIRST or LSBFIRST.
(Most Significant Bit First, or, Least Significant Bit First)
value
: the data to shift out. (byte)
Returns
Nothing