A microcontroller requires very few external components to work in an electronic circuit. The present tutorial will expose the minimum components we need to get an ATtiny841 up and running, an 8 bit microcontroller, and what is the purpose of those external elements in reference to the microcontroller.
1.2. Using an Arduino as an ISP programmer.
This tutorial explains how an Arduino Leonardo could be used as an Atmel ISP programmer so that we could burn hex files into Atmel microcontrollers natively, this way we could save up on having to buy a programmer.