This is a quick breakout board for the 74HC165 shift register which is an 8-bit parallel-in serial-out shift register, ideal for button input expansion for micro-controllers such as Arduino, ESP32 and ESP8266.

The board features 8 tactile pushbutton switches and pin headers to connect external pushbuttons. It also features duplicate pin headers for pins which are shared with a second shift register in order to allow cascading or 'daisy chaining' multiple modules for more button inputs.

The pulldown resistors are 10K but anything between 4.7K-26K should work. The decoupling capacitor is 0.1uF ceramic disc.

This board should help when developing projects with the 74HC165 allowing input from multiple buttons with just 4 wires.

To fit UM72 x70mm DIN rail enclosure e.g. CAMDENBOSS, Dinkle