Arduino UNO is the widely used microcontroller board for developing a different kind of projects and prototypes. This small development board has all the features of its native IC Atmega328p with additional features. This comes with on-board programmer CH340, so no need to connect an external programmer. Arduino Uno board has a 12V DC barrel jack which can accept up to 12V but use for 9V Max. It has onboard LEDs to indicate power. The IC Atmega328p is removable, so if the Atmega IC is not working then it can be replaced with another one.