Arduino UNO The Uno is a microcontroller board based on the ATmega328P. It has 14 digital input/output pins (of which 6 can be used as PWM outputs), 6 analog inputs, a 16 MHz quartz crystal, a USB ...

In our hardware the push button is input which is connected to the second pin of the Arduino. ... After knowing the basics about the Arduino you can try interface the basic components like 16x2 LCD, ...