Nano Relay Module

This project consists of an Arduino Nano, 74LS164N shift register, ULN2803A relay driver and SPDT relays. The aim of this is to reduce the number of wires connected with Arduino.

We took only two wires from the Nano to serial to parallel shift register. One for data and another for clock pulse. From the SR, we took 8 wires to the relay module which is already interfaced with the ULN2803A relay driver.

Shift register output pins are act as solo 8-bit port.