1x4 Independent Button Keypad - 4 Standalone Keys tv-b-gone It can serve as half-wave

It can serve as half-wave and full-wave rectifiers

Simple speed and direction control: adds useful value when choosing parts for a build

There are two arrays

10 x analog inputs

and other small controllers

1x4 Independent Button Keypad - 4 Standalone Keys tv-b-gone It can serve as half-waveHere's a pretty nifty device! The Keypad 1x4 Independent Button is an Arduino compatible electronic module that offers four momentary button inputs for your projects. You can connect to it using the five male header pins onboard. Each of the four buttons has one pin, and the remaining connects to the common ground line. Specifications: Size: 37*15*11mm Library: None Inclusions: 1 x 4 Independent Key Button Keypad Keyboard Module Documents: Close Up