SN74HC165 is a parallel In, Serial Out shift register.   I use it for dip switches controlling LEDs  Dip switch 0/1 read in and I send the signal to the SN74HC595 SIPO SR to control the LEDs.  

8 Bit
Parallel In, Serial Out

SH74HC165 to Arduino
Pin 1: Parallel load
Pin 2: Clock
Pin 7: Data
Pin 15: Clock Enable

Parallel Inputs:  A to H
Wide operating voltage range of 2 V to 6 V


int ploadPin = 7; // Connects to Parallel load pin the 165
int clockEnablePin = 4; // Connects to Clock Enable pin the 165
int dataPin = 5; // Connects to the Q7 pin the 165
int clockPin = 6; // Connects to the Clock pin the 165